Telecommunications
Distribution
Methods
MANUAL
14th Edition
Volume 1
We welcome all comments about this manual. If you have any questions about BICSI and its services, please
contact our office at 800.242.7405 (USA/Canada toll free);+ 1 813.979.1991; fax+ 1 813.971.4311; e-mail
bicsi@bicsi.org; Website www.bicsi.org.
BICSIID, Tampa, FL 33637
© 2020 BICS P'
All rights reserved.
Fourteenth edition published 2020
First printing February 2020
Printed in the United States ofAmerica
All rights reserved
ISBN (Print) 978-1-928886-82-2
ISBN (Electronic) 978-1-928886-85-3
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No part of this manual may be used, reproduced, or transmitted in any form or by any means, electronic or
mechanical, including photocopying, recording, or by any information storage and retrieval system, without
prior agreement and written permission from BfCSL
The contents ofthis manual are subject to revision without notice due to continued progress in information
and communications technology (ICT) methodology, design, and manufacturing.
THIS MANUAL IS SOLD AS IS, WITHOUT WARRANTY OF ANY KIND, RESPECTING THE
CONTENTS OF THIS MANUAL, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES
FOR THE MANUAL'S QUALITY, PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR ANY
PARTICULAR PURPOSE. BTCSI SHALL NOT BE LIABLE TO THE PURCHASER OR ANY OTHER
ENTITY WITH RESPECT TO ANY LIABILITY, LOSS, OR DAMAGE CAUSED DIRECTLY OR
INDIRECTLY BY THIS MANUAL.
BICSI World Headquarters
8610 Hidden River Parkway
Tampa, FL 33637-1000 USA
Tel.: +1 813.979.1991 or
·rei.: 800.242.7405 (USA & Canada toll-free)
Fax: +I 813.971.4311
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Website: www.bicsi.org
~.®
Bicsi
Thank you for ordering the Telecommunications Distribution iVJethods Manual, 14th edition. Please place the
chapter tabs and appendix tabs in f]·ont of the title page for each chapter and appendix.
The section tabs should be inserted in front of the following pages:
Chapter 5: Horizontal Distribution Systems
5-5
Horizontal Cabling Systems
5-65
Horizontal Pathways
5-117
ADA Requirements
Chapter 21: Project Administration and Execution
21-1
Professional Development
21-5
Project Management
21-63
Disaster Recovery Planning and Risk Management
Chapter 22: Special Design Considerations
22-5
MICE Considerations
This publication is not a single source document but a compendium of many sources of information
and communications technology (ICT)-related practices, processes, and procedures.
The information contained in this publication includes, but is not limited to, national and international codes,
de jure and de facto standards, and industry-accepted best practices terminology. All source information can
be found in Appendix A: Codes, Standards, Regulations, and Organizations and the Bibliography section of
this manual.
BICSI® recommended best practices are industry established best practices and not specifically developed
by BICSI. When necessary, BICSI will select and recommend widely used and acceptable methods for
the performance of a particular task or process based on numerous factors, including, but not limited to,
widespread field acceptance, manufacturer's recommended methods, and safety.
WARNING
It is the responsibility of the user of this manual to determine the use of the applicable safety and
health practices (e.g., in the United States, Occupational Safety and Health Administration [OSHA],
National Electrical Code® [NEG®], National Electrical Safety Code [NESC®]) associated with ICT
installation and design practices. BICSI shall not be liable to the purchaser or any other entity with
respect to any liability, loss, or damage caused directly or indirectly by application or use of this
manual. No project is so important nor any completion deadline so critical to justify nonconformance
to ICT industry standards. This publication does not address safety issues associated with its use. It
is the ICT industry professional's responsibility to use established and appropriate safety and health
practices and to determine the applicability of all regulatory issues.
New TDMM is the Blueprint for the Modern ICT Industry
Greetings and welcome to the brand new 14th edition of BlCSl's flagship manual, the
Telecommunications Distribution Methods· Manual (TDMM)- the blueprint for the modern
ICT industry! I have relied on the TDMM over many years in my day-to-day duties as a
senior-level Telecommunications Engineer and even participated in the review cycle for
the 13th edition, but this new edition has special meaning as I was tasked with being the
Publication Subject Matter Expert Team Leader responsible for overseeing its creation.
Given the rapidly changing world of ICT, creating a thorough, current reference manual can
be a challenge. Fortunately, the volunteer review team was nothing short of outstanding.
Representing all facets of the ICT industry from around the world, and collectively having
more than 500 years of experience, the team worked diligently and consistently to review the
current material. The result is a reference manual that is accurate, current, and compliant with
applicable codes and standards.
This edition also is notable for several firsts as it concerns BICSl reference manuals.
)
One, this is the first publication to have its content "modularized." While it has not changed
the physical presentation of the technical material within the manual, this initiative has
resulted in several improvements to the manual review and development process. These
include easier editing, streamlined adding/updating of material, better version control, and the
ability to have material readily available to use in other related BICSI publications.
Two, this edition of the TDMMhas been fully mapped to the requirements contained within
the RCDD Job Tasks Analysis (JTA) document. The JTA forms the basis for determining the
qualifications to hold the RCDD credential. The JTA is used not only to provide the roadmap
for the required content within the TDMM, but also detennines the RCDD credential exam
scope and the various BICSI training programs that suppmt the RCDD credential. From the
beginning of the review cycle through to the final Editorial Review, the team ensured that
all the requirements within the JTA were identified and satisfactorily addressed within the
manual content.
Some of the updates in this 14th edition include:
1. Additions to reflect the latest applicable codes, standards and regulations.
2. A revised chapter to more clearly outline the ICT designer's role in project design and
execution as part of overall project management.
3. A new section covering Disaster Recovery and Risk Management incorporated with
Project Administration and Execution.
4. A new chapter on Special Design Considerations to address premises other than typical
commercial types.
5. Expanded Power over Ethernet content (e.g., power source, link layer discovery protocol)
with new figures and tables.
6. A new section on Circuit and Pathway Designations that covers Classes
(e.g., Class A, B, C) and Levels (e.g., Level 0, I, 2) with additional figures.
8610 Hidden River Pkwy, Tampa, FL 33637-1000 USA / Tel: +1813.979.1991 or 800.242.7405 (USA & Canada toll-free) / Fax: +1813.971.4311 / Web: www.bicsi.org
7. Added information on Category 8 copper and OMS multimode optical fiber cables per the
applicable TIA standards, and specifications that OM I and OM2 multimode fiber are now
to be used to expand existing installations only.
8. Updated information in chapters related to Health Care, Wireless Networks, Electronic
Safety and Security, Data Centers, Building Automation Systems, Outside Plant, and
Audiovisual Systems to reflect latest technologies and methods.
Development ofthe 14th edition ofthe TDM!vfwas truly a TEAM effort. There arc two
groups that were instrumental in this regard, and I cannot thank them enough for their time,
dedication, effort, help, and guidance in the production of this edition of the TDMlvf.
The first is the dedicated volunteer Chapter/Section Subject Matter Expert Team Leaders and
their respective Subject Matter Expert team members, many of whom are members ofthe
BlCSI Technical Information and Methods Committee, and the volunteer members from the
BlCSI Registration and Credentials Supervision Committee who assisted with the review of
the manual material for compliance with the RCDD JTA document.
The second is the BICSI staff members from the Professional Development, Publications,
Standards, Credentialing, and Administrative departments and groups within the BICSI
organization. These individuals were indispensable in supporting and guiding the volunteers
with logistics, oversight, and the necessary work to create a professional, user-friendly, and
valuable publication for the lCT industry. Much of this work is invisible to many within
the BICSI membership, but the dedication of the staff members to BICSI and its members is
beyond phenomenal and is truly a labor of love on their part.
Whether you are just beginning your career in the ICT industry or are a seasoned veteran,
Thope you will find this 14th edition ofthe TDMM a useful addition to your reference
materials. As always, feedback from you, good and bad, on the scope and content of the
TDMM is most certainly welcome! If you feel you can be a contributor to the content of this
and other BICSI publications, then I urge you to volunteer as a Subject Matter Expert and add
your skills, knowledge, and experience to the group that produced this manual.
Lastly, I would like to thank my grandfather and father, who were career members of the
telephone industry, starting with the old Bell System and ending with Verizon. Their interest
in sharing, teaching, and mentoring me in the various facets of the industry over the years has
provided me with a roadmap in all facets of my lCT career from Lineman, Installer, Crew
Chief, Trainer, and Senior Design Engineer. Their legacy is the reason for my enthusiasm and
success within both BICSI and the ICT industry over the years.
All the Best,
Robert B. "Bob" Hertling Jr., RCDD, OSP
Vice-Chair, BICSI Technical Information and Methods Committee
Acknowledgments
BICSI's 'T'echnicallnformation and Methods (TI&M) Committee serves to coordinate the
information within all ofBICSI's technical publications. BICSI officers, membership, and
Publications staff wish to thank the TI&M Committee and its many volunteer contributors
who helped in the development of the fourteenth edition of BlCSI's Telecommunications
Distribution Methods Manual (TDMM).
The f()llowing dedicated TI&M Subject Matter Expert Team Leaders (SMETLs) and Subject
Matter Experts (SMEs) provided the key expertise required for the development of this
manual's technical content:
Tl&M Chair:
MichaelA. Collins, RCDD, RTPM; AT&T
TI&M Vice-Chair and TDMM 14th Edition
SMETL:
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons T!-ansportation Group
Chapter 1:
Principles of Transmission
Richard S. Anderson, RCDD; Servamatic
SMETL:
SME Contributors:
Chapter 2:
Electromagnetic
Compatibi1ity
SMETL:
SME Contributors:
© 2020 BICSI®
Chris Frazer, RCDD; Layer Zero Services
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons T!-ansportation Group
Mike Patterson, RCDD, PE; Physical Layer
Telecommunications Consulting, LLC
Scott Smith, RCDD, TECH, CT; JCT Ti-aining
Group, LLC
Kiyofmni Tomonaga, RCDD, ESS; KT Consulting
Dr. Paulo Sergio Marin, EE/BSc MSc, PhD;
Electrical Engineer/JCT Consultant
Gordon .J. Ash, RCDD, CTS; Ford Motor Company
Joseph A. Concepcion, RCDD, OSP; Physical Layer
Telecommunications Consulting, LLC
George M. Fewell, RCDD; NCllnc.
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Ti·an()portation Group
Mike Patterson, RCDD, PE; Physical Layer
Telecommunications Consulting, LLC
John Romanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
TDMM, 14th edition
Acknowledgments, continued
Chapter 3:
Telecommunications Spaces
SMETL:
Ray Emplit; Harger Lightning and Grounding
SME Contributors:
Chapter 4:
Backbone Distribution
Systems
TDMM, 14th edition
Gordon .J. Ash, RCDD, CTS; Ford Motor Company
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
rVal-lvfart Stores Inc.
George M. Fewell, RCDD; NCI Inc.
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
John Romanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
Barry Shambrook, RCDD; Tuckers Consultan(v Ltd
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
SMETL:
George M. Fewell, RCDD; NCI Inc.
SME Contributors:
RichardS. Anderson, RCDD; Servamatic
Marl\: Corp, RCDD, OSP, RTPM, TECH, CT;
Wai-Mart Stores Inc.
James R. "Ray" Craig, RCDD, NTS, TECH, CT,
CDCTP; Craig Consulting Services
Ray Emplit, Harger Lightning and Grounding
RobertS. '"Bob" Erickson, RCDD, NTS, OSP, WD,
RTPM; Communications Network Design
Robert B. "Bob" Hertling .Jr., RCDD, OSP;
Parsons· Transportation Group
John Romanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
Scott Smith, RCDD, TECH, CT; 1CT Training
Group, LLC
ii
© 2020 BICSI®
Acknowledgments, continued
Chapter 5:
Horizontal Distribution
Systems
SMETL:
SME Contributors:
Chapter 6:
ICT Cables and Connecting
Hardware
© 2020 BICSI®
SMETL:
Sl\fE Contributors:
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
vVi:d-Mart Stores Inc.
Ray Emplit, Harger Lightning and Grounding
Kandasamy Ganesan, RCDD, NTS, DCDC, TECH,
CT, CTS; e-sharp Computer Training
Robert B. "Bob" Hertling .Jr., RCDD, OSP;
Parsons Transportation Group
F. Patrick Mahoney, RCDD, CST CDT; Direct
Suppzv, Inc.
Michael Watts, TECH; Noovis
Philip W. Janeway, RCDD; JDH Contracting
Chris Frazer, RCDD; Layer Zero Services
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
Kiyofumi Tomonaga, RCDD, ESS; KT Consulting
iii
TDMM, 14th edition
Acknowledgments, continued
Chapter 7:
Firestop Systems
SMETL:
SME Contributors:
Chapter 8:
Bonding and Grounding
(Earthing)
Chapter 9:
Power Distribution
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
Wal-Mart Stores Inc.
Chris Frazer, RCDD; Layer Zero Services
Philip W..Janeway, RCDD; JDH Contmcting
John Romansid, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
.James Stahl Jr., ITS Consultant; Specified
Technologies, Inc.
SMETL:
Ray Emplit, Harger Lightning and Grounding
SME Contributors:
Peter Oldcrs, RCDD, NTS, OSP, TECH;
CompuServe
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
SMETL:
SME Contributors:
TDMM, 14th edition
Justin Pine, RCDD; Specified Technologies, Inc.
Brent .J. Lehmkuhl, RCDD, PE; The Johns Hopkins
Universi~v Applied Physics Laboratory
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
Wal-Mart Stores Inc.
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
John Romansld, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
Vince Saturno, PE, LEED AP, DCEP; Whitman,
Requardt and Associates
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
iv
© 2020 BICSI®
Acknowledgments, continued
Chapter 10:
Telecommunications
Administration
SMETL:
SME Contributors:
Chapter 11:
Field Testing of
Structured Cabling
SMETL:
SME Contributors:
Chapter 12:
Outside Plant
SMETL:
SME Contributors:
© 2020 BICSI®
Jonathan L. Jew, ITS Consultant; .J&M
Consultants, Inc.
John C. Adams, RCDD, OSP, CT; Adams Telecomm
Mark Corp, RCDD, OSP, RTPM, TECH, Cl';
Wai-Mart Stores Inc.
Robert S. "Bob" Erickson, RCDD, NTS, OSP, WD,
RTPM; Communications Network Design
Robert B. "Bob" Hertling .Jr., RCDD, OSP;
Parsons Transportation Group
Scott Smith, RCDD, TECH, CT; ICT Training
Group, LLC
.James R. "Ray" Craig, RCDD, NTS, TECH, CT,
CDCTP; Craig Consulting Services
Craig Buckingham, RCDD; R&M
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
Wal-lvlart Stores Inc.
George M. Fewell, RCDD; NCI!nc.
Robert B. "Bob" Hertling .Jr., RCDD, OSP;
Parsons Transportation Group
Scott Smith, RCDD, TECH, CT; JCT Training
Group, LLC
Kiyofmni Tomonaga, RCDD, ESS; KT Consulting
.John C. Adams, RCDD, OSP, CT; Adams Telecomm
Joseph A. Concepcion, RCDD, OSP; Physical Layer
Telecommunications Consulting, LLC
Robert S. "Bob" Erickson, RCDD, NTS, OSP, WD,
RTPM; Communications Network Design
George M. Fewell, RCDD; NCI Inc.
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
David W. Houtz, RCDD, OSP, TECH; Puwerhouse
Communications, LLC
.John Romanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
Dale A. Shinseld-Hironaka, Department of the
US. Army
v
TDMM, 14th edition
Acknowledgments, continued
Chapter 13:
Audiovisual Systems
SMETL:
SME Contributors:
Chapter 14:
Building Automation Systems
Chapter 15:
Data Networks
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
Wed-Mart Stores inc.
F. Patrick Mahoney, RCDD, CSI CDT: Direct
Supply, Inc.
John Romansld, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
SMETL:
Beatriz M. "Hetty" Bezos, RCDD, NTS, OSP, WD,
ESS, DCDC, CT; Bezos Technologies
SME Contributors:
Gordon J. Ash, RCDD, CTS; Ford lvfotor Company
Mark Corp, RCDD, OSP, RTPM, TECll, CT;
Waf- Mart Stores Inc.
George M. Fewell, RCDD; NCI Inc.
Robert B. "Hob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
F. Patrick Mahoney, RCDD, CSI CDT; Direct
Supply, Inc.
SMETL:
SME Contributors:
TDMM, 14th edition
Gordon .J. Ash, RCDD, CTS; Ford Motor Company
Chris Scharrer, RCDD, NTS, OSP, WD; Square
Mile Systems. Inc.
Craig Bucldngham, RCDD; R&M
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
Shawna Irwin, RCDD, WD; City of Overland
Park, Kansas
vi
© 2020 BICSI®
Acknowledgments, continued
Chapter 16:
\-Vireless Networks
SMETL:
SME Contributors:
Chapter 17:
Electronic Safety
and Security
SMETL:
SME Contributors:
© 2020 BICSI®
Mike Patterson, RCDD, PE; Physical Layer
Telecommunications Consulting, LLC
Gordon J. Ash, RCDD, CTS; Ford Motor Company
Craig Buckingham, RCDD; R&M
Joseph A. Concepcion, RCDD, OSP; Physical L(zver
Telecommunications Consulting, LLC
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
Wai-Mart Stores Inc.
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons T!·ansportation Group
John Romanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting .S'ervices. Inc.
Dr. Paulo Sergio Marin, EE/BSc MSc, PhD;
Electrical Engineer/ICT Consultant
F. Patrick Mahoney, RCDD, CST COT; Direct
Supply, Inc.
Mark Corp, RCDD, OSP, RTPM, TECH, CT;
rVai-Mart Stores Inc.
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
.John Romanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
vii
TDMM, 14th edition
Acknowledgments, continued
Chapter 18:
nata Centers
SMETL:
Jonathan L. Jew, ITS Consultant; J&M
Consultants·, Inc.
SME Contributors:
Gordon .J. Ash, RCDD, CTS; Ford Motor Company
Beatriz M. "'Betty" Bezos, RCDD, NTS, OSP, WD,
ESS, DCDC, CT; Bezos Technologies
Stuart Kennedy, RCDD; Morgan Stanley
John H.omanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, Inc.
Barry Shambrook, RCDD; Tuckers Consultancy Ltd
Chapter 19:
Health Care
SMETL:
SME Contributors:
F. Patrick Mahoney, RCDD, CST CDT; Direct
Supply, Inc.
Gordon .J. Ash, RCDD, CTS; Ford Motor Cmnpany
Robert B. "Bob" Herding Jr., RCDD, OSP;
Parsons Transportation Group
Chapter 20:
Residential Cabling
SMETL:
SME Contributors:
Richard S. Anderson, RCDD; Servamatic
Robert B. "Bob" Hertling .Jr., RCDD, OSP;
Parsons Transportation Group
Philip W. Janeway, RCDD; JDH Contracting
TDMM, 14th edition
viii
© 2020 BICSI®
Acknowledgments, continued
Chapter 21:
J>roject Administration
and Execution
Chapter 22:
Special Design
Considerations
SMETL:
SME Contributors:
SMETL:
SME Contributors:
Appendix A:
Codes, Standards,
Regulations, and
Organizations
© 2020 IUCSI®
SMETL:
SME Contributors:
Philip W. Janeway, RCDD; JDH Contracting
Gordon .J. Ash, RCDD, CTS; Ford iVfotor Company
Beatriz M. "Betty" Bezos, RCDD, NTS, OSP, WD,
ESS, DCDC, CT; Bezos Technologies
RobertS. "Bob" Erickson, RCDD, NTS, OSP, WD,
RTPM; Communications Network Design
Robert U. "Bob" Herding .Jr., RCDD, OSP;
Parsons Transportation Group
Shawna Irwin, RCDD, WD; City of Overland
Park, Kansas
John Romanski, OSP, WD, ESS, DCDC, RTPM;
Precision Contracting Services, inc.
Robert B. "Bob" Hertling .Jr., RCDD, OSP;
Parsons Transportation Group
Philip W. Janeway, RCDD; JDH Contracting
Robert B. "Bob" Hertling .Jr., RCDD, OSP;
Parsons Transportation Group
Paul Cave, RCDD, RTPM, TECH; Excel
Murat Erenturk, DCDC; Goradata Consulting and
Sofiware Ltd.
Anthony Frassetta, RCDD, NICET; Kimball
Corporation
Gautier Humbert, RCDD; Legrand
Philip W. .Janeway, RCDD; JDH Contracting
Youngsoo Kim, RCDD, PE, LEED AP BD-+-C; Jacobs
Miguehingel Ochoa, RCDD; JTTERA
Peter Olders, RCDD, NTS, OSP, TECH;
CompuServe
Karin Pasalich, Aecom Australia Pty. Ltd.
Peter N. Rock, RCDD, NTS; United States Army
Network Enterprise Technology Command
Murray Teale, VTJ Services
.Juan Enrique Torres, Neutel
Bruce Turner, RCDD, NTS, DCDC; Aurecon
ix
TDMM, 14th edition
Acknowledgments, continued
Appendix B:
Legal Considerations
SMETL:
SME Contributors:
Bibliography:
SMETL:
SIVlE Contributor:
Master Glossary:
SMETL:
SME Contributors:
TDMM, 14th edition
M. Georgia Gibson Henlin, QC; Hen/in Gibson
Hen/in Attorneys·-at-Law & Notaries Public
Gordon J. Ash, RCDD, CTS; Ford Motor Company
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
Robert B. "Bob" Hertling Jr., RCDD, OSP;
Parsons Transportation Group
Jeff Silveira, RITP, CAE;
BICSI Director of Standards
Justin Pine, RCDD; Specified Technologies, Inc.
Beatriz M. "Betty" Bezos, RCDD, NTS, OSP, WD,
ESS, DCDC, CT; Bezos Technologies
.Joseph A. Concepcion, RCDD, OSP; Physical Laver
Telecommunications Consulting, LLC
Ray Emplit; Harger Lightning and Grounding
Larry L. Hamlin, RCDD, OSP, CHIP;
Black & Veatch
Philip W. Janeway, RCDD; JDH Contracting
Reece ".Jay" Miller, RCDD; ICT Consultant
Mike Patterson, RCDD, PE; Physical Layer
Telecommunications Consulting, LLC
© 2020 BICSI®
Acknowledgments, continued
RCSC Pre-Editorial JTA Review, Tampa, FL, February 11-12, 2019
RobertS. "Bob" Erickson, RCDD, N'T'S, OSP, WD, RTPM
Brian Ensign, RCDD, NTS, OSP, RTPM
Brian Hansen, RCDD, NTS
Robert B. "Bob" Hertling, RCDD, OSP
Russell "Russ" Oliver, RCDD, NTS, ESS, DCDC, RTPM
Participants, TDMM 14th Edition Editorial Review, Tampa, FL, February 13-16, 2019:
Richard S. Anderson, RCDD
Michael A. Collins, RCDD, RTPM
Mark Corp, RCDD, OSP, RTPM, TECH, CT
Ray Emplit
Brian Ensign, RCDD, NTS, OSP, RTPM
Robert S. "Bob" Erickson, RCDD, NTS, OSP, WD, RTPM
George M. Fewell, RCDD
Robert B. "Bob" Hertling, RCDD, OSP
Philip W. Janeway, RCDD
F. Patrick Mahoney, RCDD
.Justin Pine, RCDD
John Romanski, OSP, WD, ESS, DCDC, RTPM
BICSI Staff Attending:
Allen Dean
John Ditzel
.Jeff Giarrizzo
Clarke W. Hammersley
Gail Moore-Swaby
.Jeff Silveira, RITP, CAE
Editorial Review Logistics:
Audrey Linn
© 2020 BICSI®
xi
TDMM, 14th edition
Acknowledgments, continued
The following BICSI Professional Development statT members produced this manual at BICSI World
Headquarters, Tampa, FL:
Vice President of
Professional Development:
Gail Moore-Swaby
Project Manager/
Director of Publications:
Clarke W. Hammersley
Lead Technical Editor:
Jeff Giarrizzo
Co-Technical Editors:
Allen Dean
Amy Woodland (under contract)
Senior Publications Designer:
John Ditzel
TDMM, 14th edition
xii
© 2020 BICSI®
About BICSI. .. Advancing Information and Communications
Technology (ICT)
BICSI provides information, education, and knowledge assessment for individuals
and companies in the ICT industry. We serve more than 23,000 lCT professionals,
including designers, telecommunications project managers, installers, and technicians.
These individuals provide the fundamental infrastructure and project management for
telecommunications, audio/video, life safety, and automation systems. Through courses,
conferences, publications, and professional registration programs, BICSI staff and volunteers
assist ICT professionals in delivering critical products and services and offer opportunities for
continual improvement and enhanced professional stature.
Headquartered in Tampa, Florida, USA, BICSI membership spans nearly 100 countries.
BICSI Vision Statement
BICSI"" is the worldwide preeminent source of information, education, and knowledge
assessment for the constantly evolving ICT industry.
BICSI Mission Statement
BTCST's mission is to:
• Lead the ICT industry with excellence in publications, education, and knowledge
assessment.
• Advance our members' ability to deliver the highest quality products and services.
• Provide our members with opportunities for continual improvement and enhanced
professional stature.
BICSI 2020 Board of Directors
President: Todd W. Taylor, RCDD, NTS, OSP
President-Elect: Carol Everett Oliver, RCDD, ESS, DCDC
Secretary: Robert ''Bob" Erickson, RCDD, NTS, OSP, WD, RTPM
Treasurer: David M. Richards, RCDD, NTS, OSP, TECH, CT
Canadian Region Director: Fernando Neto, RCDD
EMEA Region Director: Barry Sham brook, RCDD
U.S. North-Central Region Director: Randal Reusser, TECH, CT
U.S. Northeast Region Director: William Foy, RCDD, NTS, OSP, WD, ESS
U.S. South Central Region Director: Mark Reynolds, RCDD
U. S. Southeast Region Director: Lee Renfroe, RCDD, ESS, TECH
U.S. Western Region Director: Pat McMurray, RCDD, NTS, OSP, DCDC, PMP
BICSI Executive Director & Chief Executive Officer: John H. Daniels
© 2020 BICSI®
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TDMM, 14th edition
International Credentials
BICSI's professional registration programs are internationally recognized.
• RCDD'" Credential
- Registered Communications Distribution Designer (RCDD) credential holders
demonstrate expertise in the design, implementation, integration of telecommunications
and data communications systems, and infrastructure components.
• DCDC Credential
-Data Center Design Consultant (DCDC) credential holders demonstrate knowledge
and ability over multiple facets within data center design, including the planning,
implementing, and making of critical decisions regarding data centers.
• OSP Credential
-Outside Plant (OSP) design credential holders demonstrate proficiency in the ability
to understand and apply a vast collection ofOSP technology, including right-of-way,
route design, media selection, cabling hardware, bonding and grounding (earthing), and
electrical protection systems.
• RTPM Credential
- Registered Telecommunications Project Manager (RTPM) credential holders demonstrate
proficiency in a vast collection of telecommunications project management principles,
concepts, tools, and technology.
• BICSI Installer 1; Installer 2, Copper; Installer 2, Optical Fiber; Technician
- BICST Installers and '['echnicians are proficient in the latest ICT industry standards and
codes requirements and in various topics, including the pulling, terminating, testing, and
troubleshooting of copper and optical fiber cable using BICSI global best practices as a
guide.
TDMM, 14th edition
xiv
© 2020 BICSI®
Become a BICSI Member!
BICSI membership is your key to a successful career in the ICT industry. Member benefits
extend into the technical, legislative, and even the financial realms of this competitive
industry. Membership offers ample opportunities for professional networking and career
development and advancement. Join BICSl and combine your expertise with your colleagues
in the network of ICT professionals.
Member Benefits
Gain the Competitive Edge!
Combine all the benefits of BlCSI membership into one complete package and you will
understand why BTCSl members hold a competitive advantage. BICSI keeps you ahead
of your competition through a continuous flow of new information in the fast-changing
ICf field. By prominently displaying your BICSI membership, you make known your
professional ability to industry contacts.
fast Access to Information
BICSI's website (www.bicsi.org) is a quick way to find a wide variety of detailed BICSI
information. While on the website, find answers to industry questions and communicate with
members and colleagues through BlCSl's online forums and social media sites. Search for
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Member Discounts
BICSI members receive substantial discounts on quality education-publications, standards,
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Educational Conferences
Each year, BICSI hosts conferences in North America as well as regularly scheduled
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BICSI also offers a variety of other local educational opportunities in the form of region
meetings, Breakfast Clubs, Pub Clubs, and Lunch and Learns.
Technical Publications
Become a member and you will receive substantial discounts on BICSl 's highly acclaimed
publications long considered the definitive reference source ofthe industry. BICSI's
manuals serve as valuable reference and study tools for BJCSI courses and exams. BICSI
publications are based on global best practices that follow and, in many cases, exceed the
requirements of recognized international codes, standards, and regulations.
In addition to the TDMM, our publications include the Outside Plant Design Reference
Manual (OSPDRM), Telecommunications Project Management Manual (TPMM),
Jnj()rmation Technology Systems Installation Methods Manual (!T.SJMM), and many other
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TDMM, 14th edition
Member Benefits, continued
Our standards include ANSI/BICSI 001, Il(/ormation and Communication Technolot,ry
Systems Design and Implementation Best Practices for Educational Institutions and
Facilities; ANSIIBICSl 002, Data Center Design and hnplementation Best Practices;
ANSI/BICSI 003, Building Information Modeling (BIM) Practices for b(/ormation
Technology Systems; ANSf!BICSI 004, Information Communication Technology .~)!stems
Design and Implementation Best Practices for Healthcare Institutions and Facilities;
ANSI/BICSI 005, Electronic Safety and Security (ESS) System Design and Implementation
Best Practices; ANSI/BICSI 006, Distributed Antenna System (DAS) Design and
Implementation Best Practices; ANSI/BICSI 007, b((ormation Communication Technology
Design and Implementation Practices for intelligent Buildings and Premises;
ANSJ/BICST 008, Wireless Local Area Net>vork (WLAN) Systems Design and Implementation
Best Practices; BICSI G 1-17, ICT Outside Plant Construction and Installation: General
Practices; ANSl/BICSI N 1, installation Practicesfbr Telecommunications and ICT Cabling
and Related Cabling Infi·astructure, and ANSI/BTCST N2, Practices For The b1stallation of
Telecommunications and ICT Cabling Intended to Support Remote Power Applications.
loin BICSI Today!
BlCSf membership is open to individuals and corporations serving the IC'r and building
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TDMM, 14th edition
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© 2020 BICSI®
BICSI Policy for Numeric Representation of Units
of Measurement
BICSI technical manuals primarily follow the modern metric system, known as
the International System of Units (SI). The Sl is intended as a basis for worldwide
standardization of measurement units. With the exception of conduit measurements, units of
measurement in this manual are expressed in general and approximate Sl terms, followed by
an equivalent imperial (U.S. customary) unit of measurement in parentheses (see exceptions
listed below):
• In general, approximate (soft) conversions are used in this manual and are denoted with
the approximate symbol(:::::;) in front of the metric number. Approximate conversions are
considered reasonable and practicable; they are not precise equivalents. In some instances,
equivalents (hard conversions) may be used when it is a:
- Manufacturer requirement for a product (e.g., conduit sizes).
- Standard or code requirement.
- Safety factor.
• ln general, approximate Sl units of measurement are convQrted to an imperial unit of
measurement and placed in parentheses. Exception: When the reference material from
which the value is pulled is provided in imperial units only, the imperial unit is the
benchmark.
• For metric conversion guidelines, refer to IEEE/ ASTM SI 10, A1nerican National Standard
frJr Metric Practice.
• Trade size is approximated for both metric and non-metric purposes. Example:
: : :; 100 millimeters (mm [4 trade size]).
• In some instances (e.g., optical fiber media specifications), the physical dimensions and
operating wavelengths are designated.
© 2020 BICSI®
xvii
TDMM, 14th edition
HOW TO USE THIS MANUAL
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Chapter number and name are indicated '
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1: Principles of Transmission
I Chapters are divided into sections. I
Section Heading
Topic Heading
Each chapter
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• Bullets indicate important terms and phrases.
Bullets are often followed by more detailed information.
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TDMM, 14th edition
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1
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'~========:-:-,-scc:""'='~~77":c~~~~"'""~c-c:J1 page number.
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TDMM, 14th edition
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© 2020 BICSI®
© 2020 BICSI®
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Teleconmumications Distribution Methods Manual (TDMM), 14th edition
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xix
TDMM, 14th edition
Table of Contents
Table of Contents
Chapter 1: Principles of Transmission
Metallic Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Electrical Conductors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
American Wire Gauge (AWG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Balanced Twisted-Pair Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Environmental Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Cable Shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Drain Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Analog Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
Digital Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Types of Transmission Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-39
Asynchronous and Synchronous Transmission . . . . . . . . . . . . . . . . . . . . . . . . . 1-40
Digital Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-41
Video Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
Transmission Line Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-48
Balanced Twisted-Pair Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-57
Balanced Twisted-Pair Channel Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-58
Balanced Twisted-Pair Permanent Link Performance . . . . . . . . . . . . . . . . . . . . . 1-62
Balanced Twisted-Pair Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-63
Optical Fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-78
Optical Fiber Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-79
Optical Fiber Receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
Optical Fiber Medium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-89
Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-91
Optical Fiber Applications Support Information . . . . . . . . . . . . . . . . . . . . . . . . . 1-103
Verifying Optical Fiber Performance and Electronics Compatibility . . . . . . . . . . . . 1-105
Selecting an Optical Fiber Core Size to Application or Original Equipment
Manufacturer (OEM) Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-116
Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy
(SOH) Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-116
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-121
© 2020 BICSI®
TDMM, 14th edition
Table of Contents
Chapter 2: Electromagnetic Compatibility
Electromagnetic Compatibility (EMC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Electromagnetic Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Electromagnetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Measuring Electromagnetic Compatibility (EMC) . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Electromagnetic Interference (EMI)-A Problem . . . . . . . . . . . . . . . . . . . . . . . . 2-12
Electromagnetic Compatibility (EMC)-The Solution . . . . . . . . . . . . . . . . . . . . . . 2-15
Electromagnetic Interference (EMI) and Cabling . . . . . . . . . . . . . . . . . . . . . . . . 2-18
Electromagnetic Qualification Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
Unwanted Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24
Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27
Minimizing Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
Considerations for Electromagnetic Compatibility (EMC) in Cabling Systems ..... 2-36
Interference Reduction in Shielded Rooms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42
Telecommunications Cabling within Joint-Use Tunnel . . . . . . . . . . . . . . . . . . . . . 2-44
Chapter 3: Telecommunications Spaces
Telecommunications Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Telecommunications Spaces Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Telecommunications Rooms (TRs) and Telecommunications Enclosures (TEs) .... 3-18
Telecommunications Room (TR) and Telecommunications Enclosure (TE)
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
Telecommunications Room (TR) Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
General Requirements for All Telecommunications Enclosures (TEs) . . . . . . . . . . 3-26
Equipment Rooms (ERs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
Equipment Room (ER) Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-30
Locating the Equipment Room (ER) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
Space Allocation and Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37
Cable Installation and Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42
Electrical Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
Heating, Ventilation, and Air-Conditioning (HVAC) Environmental Control ...... 3-48
Miscellaneous Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Design Approval, Buildout, and Final Inspection . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Entrance Facilities (EFs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52
TDMM, 14th edition
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© 2020 BICSI®
Table of Contents
Chapter 4: Backbone Distribution Systems
Backbone Distribution Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Cabling Topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Hierarchical Star Campus Backbone Designs . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Telecommunications Rooms (TRs) and Telecommunications Enclosures (TEs) .... 4-31
Building Backbones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-32
Choosing Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38
Backbone Building Pathways (Internal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41
Miscellaneous Support Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-47
Bonding and Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-49
Backbone Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-49
Indoor Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
Ethernet in the First Mile (EFM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
Chapter 5: Horizontal Distribution Systems
Horizontal Distribution Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
SECTION 1: HORIZONTAL CABLING SYSTEMS
Horizontal Cabling Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Horizontal Cabling Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Work Areas and Open Office Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
Simultaneous Data and Power Transmission within Horizontal Cabling . . . . . . . . . 5-37
Centralized Optical Fiber Cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
Fiber-To-The-Outlet (FTTO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-48
Horizontal Pathways for Fiber to the Office (FTTO) Systems
. . . . . . . . . . . . . . . 5-53
Passive Optical Networks (PONs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-56
SECTION 2: HORIZONTAL PATHWAYS
Horizontal Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-65
Types of Horizontal Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-70
Ceiling Distribution Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-93
Other Horizontal Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-110
SECTION 3: ADA REQUIREMENTS
Americans with Disabilities Act (ADA) Requirements . . . . . . . . . . . . . . . . . . . . 5-117
Appendix: Disabled Access and the Americans with Disabilities Act (ADA) ..... 5-125
© 2020 BICSI®
iii
TDMM, 14th edition
Table of Contents
.Chapter 6: ICT Cables and Connecting Hardware
ICT Cables and Connecting Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Balanced Twisted-Pair Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Optical Fiber Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
Coaxial Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
Balanced Twisted-Pair Connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-33
Balanced Twisted-Pair Connecting Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-55
Balanced Twisted-Pair Connecting Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-61
Optical Fiber Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-77
Optical Fiber Connecting Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Coaxial Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-95
Coaxial Connecting Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-103
Chapter 7: firestop Systems
Firestop Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Firestop and Disaster Avoidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Fire-Resistance Rated Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Firestop Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Testing and Guidelines for Firestops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11
Types of Firestop Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19
Firestop for Brick, Concrete Block, and Concrete Walls . . . . . . . . . . . . . . . . . . . 7-32
Firestop for Framed Wall Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-36
Firestop for Lath and Plaster Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-42
Firestop for Combination Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-42
Firestop for Floor Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-43
Firestop for Floor/Ceiling Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-44
Structural Steel Floor Units with Concrete Floor Fill without Suspended
Ceiling Membranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-47
Firestop for Roof/Ceiling Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-47
Fire-Rated Vertical Shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-48
Firestop for Curtain Wall Floor/Ceiling Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49
General
Firesto~
Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-52
Appendix A: Approved Firestop Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-54
Appendix B: Testing and Guidelines for Firestops . . . . . . . . . . . . . . . . . . . . . . 7-108
Chapter 8: Bonding and Grounding (Earthing)
Bonding and Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Alternating Current (ac) Grounding (Earthing) Electrode System . . . . . . . . . . . . . 8-5
Equipment Grounding (Earthing) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8
Telecommunications Bonding Infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
Lightning Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26
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Chapter 9: Power Distribution
Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
Alternating Current (ac) Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2
American Wire Gauge (AWG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-15
Alternating Current (ac) Voltage Quality Problems . . . . . . . . . . . . . . . . . . . . . . 9-18
Power Distribution for Information Technology Equipment (ITE) Spaces ........ 9-25
Electrical Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-28
Power System Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-31
Power Conditioning/Power Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-36
Direct Current (de) Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-52
Installation of Direct Current (de) Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-61
Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-63
Power System Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-72
Power System Monitoring and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-75
Conductor Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-77
Chapter 10: Telecommunications Administration
Telecommunications Administration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
Identification Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
Identification Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-23
Labeling and Recordkeeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-31
Administration of Large Telecommunications Spaces . . . . . . . . . . . . . . . . . . . . 10-39
Chapter 11: field Testing of Structured Cabling
Field Testing of Structured Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
Balanced Twisted-Pair Cabling Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Balanced Twisted-Pair Cabling Acceptance Tests . . . . . . . . . . . . . . . . . . . . . . . 11-11
Coaxial Cabling Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-18
Optical Fiber Cabling Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-19
Optical Fiber Cabling Acceptance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-22
Optical Fiber Cabling Field Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-24
Maintenance and Troubleshooting for Optical Fiber Cabling . . . . . . . . . . . . . . . 11-27
Additional Optical Fiber Troubleshooting Tools and Equipment
11-28
Chapter 12: Outside Plant
Outside Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1
Telecommunications Service Entrances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6
Underground Entrances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6
Buried Entrances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-9
Aerial Entrances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-10
Other Telecommunications Service Entrance Considerations . . . . . . . . . . . . . . . 12-15
Terminating Space for Telecommunications Entrance Facilities . . . . . . . . . . . . . 12-20
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Terminating Conduit Inside a Building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-22
Network Interface (NI) Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-23
Outside Building Terminals (Pedestals and Cabinets) Pedestal Hardware
Mounted on Outside Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-25
Direct-Buried Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-26
Trenches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-28
Underground Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-32
Conduit Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-33
Terminating Conduit at a Designated Property Line . . . . . . . . . . . . . . . . . . . . . 12-38
Maintenance Hole Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-39
Aerial Plant Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-46
Chapter 13: Audiovisual Systems
Audiovisual (AV) Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-2
Types of Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-10
Environmental Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-30
Visual Display Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-38
Program Audio and Speech Reinforcement Systems . . . . . . . . . . . . . . . . . . . . 13-43
Signal Distribution Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-52
Audioconferencing Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-54
Videoconferencing Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-70
Control Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-79
Overhead Paging Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-82
Sound Masking Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-92
Digital Signage Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-96
Cable Television Distribution Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-100
Chapter 14: Building Automation Systems
Building Automation Systems (BAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1
Building Automation Systems (BAS) Interfaces with Other Systems . . . . . . . . . . 14-6
Building Automation Systems (BAS) Communications Networks . . . . . . . . . . . . 14-17
Building Automation Systems (BAS) Electrical Characteristics . . . . . . . . . . . . . . 14-23
Planning Building Automation Systems (BAS) Distribution Cabling . . . . . . . . . . 14-25
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Chapter 15: Data Networks
Data Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1
Open Systems Interconnection (OSI) Reference Model . . . . . . . . . . . . . . . . . . . 15-4
Network Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8
Network Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-14
Network Supported Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-15
Network Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-19
Computer Rooms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-21
Campus and Multisite Network Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-33
Chapter 16: Wireless Networks
Wireless Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-1
Services and Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-2
Frequency and Wavelength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-6
Electromagnetic Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-14
Wireless System Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-22
Selection of Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-25
Components of a Wireless System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-28
Distributed Antenna Systems (DAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-38
Personal Area Networks (PANs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-65
Wireless LAN (WLAN) Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-67
Wireless LAN (WLAN) Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-69
Chapter 17: Electronic Safety and Security
Electronic Safety and Security (ESS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-1
Electronic and Electrical Door Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-8
Video Surveillance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-21
Intrusion Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-28
Fire Detection and Alarm Systems (FDAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-31
Fire Alarm (FA) Notification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-36
Fire Alarm Control Panels (FACP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-39
Digital Alarm Communicator System (DACS) . . . . . . . . . . . . . . . . . . . . . . . . . 17-49
Area of Refuge and Rescue Two-Way Communication Systems . . . . . . . . . . . . . 17-56
Mass Notification and Emergency Communications (MNEC) Systems . . . . . . . . . 17-59
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Chapter 18: Data Centers
Data Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-1
Data Center Redundancy and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-4
Structured Cabling Hierarchy for Data Centers . . . . . . . . . . . . . . . . . . . . . . . . . 18-9
Guidelines for Telecommunications Cabling, Cable Containment, Equipment
Racks, and Cabinets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-16
Data Center Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-24
Operation, Ownership Costs, Environmental Impact, and Efficiency. . . . . . . . . . 18-30
Data Center Planning Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-30
Chapter 19: Health Care
Health Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-1
Space and Pathway Requirements and Considerations . . . . . . . . . . . . . . . . . . . . 19-2
Nurse Call Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-10
Code Call Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-20
Hospital Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-21
Wireless Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-24
Audiovisual (AV) Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-26
Picture Archiving and Communication System (PACS) . . . . . . . . . . . . . . . . . . . 19-28
Patient Monitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-28
Radio Frequency Identification (RFID)-Based Systems . . . . . . . . . . . . . . . . . . 19-30
Interactive Patient Entertainment and Education Systems . . . . . . . . . . . . . . . . 19-33
Wayfinding and Signage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-37
Regulatory Bodies and Organizations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-38
Chapter 20: Residential Cabling
Residential Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-1
Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-4
Planning the Cabling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-19
Rough-In Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-20
Finish Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-22
Chapter 21: Project Administration and Execution
SECTION 1: PROFESSIONAL DEVELOPMENT
Professional Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-1
SECTION 2: PROJECT MANAGEMENT
Project Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-5
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SECTION 3: DISASTER RECOVERY PLANNING AND RISK MANAGEMENT
Disaster Recovery Planning and Risk Management . . . . . . . . . . . . . . . . . . . . . 21-63
The Disaster Recovery Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-67
Chapter 22: Special Design Considerations
Special Occupancies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-1
SECTION 1: MICE CONSIDERATIONS
MICE Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-5
Appendix A: Codes, Standards, Regulations, and Organizations
Codes, Standards, Regulations, and Organizations . . . . . . . . . . . . . . . . . . . . . . . A-1
International Codes and Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-6
Regional Codes and Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-30
National Codes and Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-42
Enforcement of United States (U.S.) Building Codes, Standards, and
Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-74
Wireless Transmission Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-77
Approval of Electrical Products and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . A-81
Regulations and Standards for Emissions and Immunity . . . . . . . . . . . . . . . . . . A-86
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-86
Commercial Products Marketed in the United States (U.S.) . . . . . . . . . . . . . . . . A-86
Radiation Limits for Class A and Class B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-87
Emission Limits for Class A and Class B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-88
Commercial Products Marketed Outside the United States (U.S.) . . . . . . . . . . . . A-88
Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-93
Network Interfaces and Demarcation Points in the United
States (U.S.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-93
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-94
Classifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-94
Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-94
Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-95
Analog Voice Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-96
Analog Data Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-116
Network Channel Equipment Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-134
Appendix B: Legal Considerations
Legal Aspects of Information and Communications Technology (ICT) Design ..... B-1
Glossary
Bibliography
Index
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Figures
Chapter 1: Principles of Transmission
Figure 1.1
Calculated attenuation values for cables insulated with FEP, ECTFE,
and PVC from 1 MHz to 135 MHz at 22 °C (72 °F) . . . . . . . . . . . . . . . . 1-11
Figure 1.2
Calculated and measured attenuation values for cables insulated
with FEP, ECTFE, and PVC from 1 MHz to 135 MHz at 40 °C (104 °F)
1-12
Calculated and measured attenuation values for cables insulated
with FEP, ECTFE, and PVC from 1 MHz to 135 MHz at 60 °C (140 °F)
1-12
Figure 1.3
Figure 1.4
Example 1 of a sinusoidal signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Figure 1.5
Example 2 of a sinusoidal signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
Figure 1.6
IP telephony architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27
Figure 1.7
DS1 frame format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
Figure 1.8
E1 frame format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-32
Figure 1. 9
Polar non-return-to-zero level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36
Figure 1.10
Bipolar AMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36
Figure 1.11
Biphase Manchester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36
Figure 1.12
Two binary bits encoded into one quaternary (2B1Q) . . . . . . . . . . . . . 1-36
Figure 1.13
MLT-3, also referred to as NRZI-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
Figure 1.14
Composite video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
Figure 1.15
Two-conductor transmission line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-48
Figure 1.16
Resistive model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-49
Figure 1.17
Capacitance model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-49
Figure 1.18
Inductive model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-50
Figure 1.19
Primary transmission line parameters . . . . . . . . . . . . . . . . . . . . . . . . 1-51
Figure 1.20
General transmission model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-52
Figure 1.21
Example of a channel test configuration . . . . . . . . . . . . . . . . . . . . . . . 1-58
Figure 1.22
Permanent link test configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-62
Figure 1.23
Typical configuration of endspan and midspan power source
equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-77
Figure 1.24
Spectral profile comparison of laser and LED . . . . . . . . . . . . . . . . . . . 1-80
Figure 1.25
Spectral width of an LED source showing full width half maximum .... 1-81
Figure 1.26
Numerical aperture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-82
Figure 1.27
System bandwidth versus distance example . . . . . . . . . . . . . . . . . . . . 1-91
Figure 1.28
Pulse distortion because of rise time and data rate . . . . . . . . . . . . . . . 1-93
Figure 1.29
Link bandwidth at 1300 nm using 62.5/125 micrometer multimode
optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-97
Figure 1.30
Core and coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-100
Figure 1.31
DSX optical multiplexing design . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-118
Figure 1.32
SONET multiplexing design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-119
Figure 1.33
WDM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-120
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Chapter 2: Electromagnetic Compatibility
Figure 2.1
Electromagnetic spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Figure 2.2
Dependence of the safe distance to EMI source on its power ........ 2-10
Figure 2.3
Model T for a short wire channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21
Figure 2.4
Surge test voltage waveform sample . . . . . . . . . . . . . . . . . . . . . . . . . 2-23
Figure 2.5
CM versus DM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Figure 2.6
Ground loops in shielded cabling systems . . . . . . . . . . . . . . . . . . . . . 2-28
Figure 2. 7
Ground loop because of stray capacitance at high frequencies ....... 2-29
Figure 2.8
Common impedance coupling interference . . . . . . . . . . . . . . . . . . . . . 2-30
Figure 2.9
Field-to-cable and ground loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31
Figure 2.10
Coupling reduction as function of grounding (earthing) practice ...... 2-32
Figure 2.11
Higher frequency twist decrease . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Figure 2.12
Typical power line filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39
Figure 2.13
Isolation transformer scheme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
Figure 2.14
Samples of ferrite toroids, beads, and sleeves . . . . . . . . . . . . . . . . . . 2-41
Figure 2.15
Balance concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
Figure 2.16
EMI susceptibility of circuits and systems connected through
unshielded cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
Figure 2.17
Ground loop and EMI immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47
Chapter 3: Telecommunications Spaces
Figure 3.1
Typical cabinet and rack mounting hole spacing arrangements ....... 3-15
Figure 3.2
Rack unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Figure 3.3
Space considerations when sizing a telecommunications space ....... 3-17
Figure 3.4
Typical TR layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Figure 3.5
Typical sleeve/conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
Figure 3.6
Typical shallow room layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
Figure 3. 7
Typical AP ER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
Figure 3.8
Typical ER layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38
Chapter 4: Backbone Distribution Systems
Figure 4.1
Star topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Figure 4.2
Hierarchical star topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Figure 4.3
Ring topology (simplified) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Figure 4.4
Buildings connected by a physical ring topology . . . . . . . . . . . . . . . . . . 4-9
Figure 4.5
Main backbone ring and redundant backbone star combined ........ 4-10
Figure 4.6
Physical star/logical ring topology . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Figure 4. 7
Clustered star topology with physical star/logical ring . . . . . . . . . . . . . 4-12
Figure 4.8
Bus topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Figure 4. 9
Tree and branch topology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Figure 4.10
Fully connected mesh topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
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Figure 4.11
Partially connected mesh topology . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Figure 4.12
Point-to-multipoint optical topology . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Figure 4.13
PTP optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Figure 4.14
PTP balanced twisted-pair topology . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Figure 4.15
Typical backbone hierarchical star topology for multiple buildings on
a campus (inside and outside distribution) . . . . . . . . . . . . . . . . . . . . . 4-24
Figure 4.16
Example of multiple hierarchical level campus backbone design ...... 4-26
Figure 4.17
Levels of cross-connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27
Figure 4.18
Logical bus topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28
Figure 4.19
Logical ring topology implemented using a physical star topology ..... 4-29
Figure 4.20
Logical tree topology implemented using a hierarchical star topology .. 4-29
Figure 4.21
Star building backbone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33
Figure 4.22
Hierarchical star building backbone . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34
Figure 4.23
Redundant routing for building backbone (HCs [FDs] not linked) ..... 4-35
Figure 4.24
Example of combined optical fiber/balanced twisted-pair backbone
supporting voice and data traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
Figure 4.25
ERs and AP cabling system interface cabling . . . . . . . . . . . . . . . . . . . 4-37
Figure 4.26
Typical office building pathway layout . . . . . . . . . . . . . . . . . . . . . . . . 4-44
Figure 4.27
Typical sleeve and slot installations . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45
Figure 4.28
EFM network boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
Chapter 5: Horizontal Distribution Systems
5-2
Figure 5.1
Typical horizontal cabling system elements
Figure 5.2
Horizontal cabling system channel . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Figure 5.3
Horizontal cabling system channel model with four connection points ... 5-8
Figure 5.4
Horizontal cabling system channel model with three connection points .. 5-9
Figure 5.5
Horizontal cabling system permanent link model with three
connection points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
Figure 5.6
Example of connection by means of cross-connection . . . . . . . . . . . . . 5-12
Figure 5. 7
Example of connection by means of interconnection . . . . . . . . . . . . . . 5-13
Figure 5.8
Example of connection by means of cross-connection and
interconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Figure 5.9
Example of connection by means of double cross-connection ........ 5-15
Figure 5.10
Total cable length in the horizontal cabling system channel . . . . . . . . . 5-18
Figure 5.11
Pin/pair assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
Figure 5.12
Typical dimensions for furniture opening for telecommunications
faceplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
Figure 5.13
Example of MUTOA application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
Figure 5.14
CPs used in a combined furniture system and private office work
area environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Figure 5.15
CPs located on all columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Figure 5.16
CPs located in a space between the columns . . . . . . . . . . . . . . . . . . . 5-34
Figure 5.17
CPs located in checkerboard order . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
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Figure 5.18
CPs located on columns close to the building core . . . . . . . . . . . . . . . . 5-36
Figure 5.19
Temperature versus wattage for category cable types
Figure 5.20
Insertion loss versus temperature for category cable types . . . . . . . . . 5-39
Figure 5.21
Centralized optical fiber cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45
Figure 5.22
Traditional structured cabling LAN design compared with FTTO LAN ... 5-49
Figure 5.23
Traditional active Ethernet design compared with PON-based
architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-56
Figure 5.24
Underfloor conduit extended to individual telecommunications outlet
boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-70
Figure 5.25
Typical underfloor conduit system . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-71
Figure 5.26
Conduit bodies recommended for telecommunications cables . . . . . . . . 5-72
Figure 5.27
Recommended pull box configurations . . . . . . . . . . . . . . . . . . . . . . . . 5-82
Figure 5.28
Stringered access floor system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-86
Figure 5.29
Recommended clearance for access floor spaces . . . . . . . . . . . . . . . . . 5-88
Figure 5.30
Typical zoned ceiling (plan view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-96
Figure 5.31
Conduit-based ceiling zone (elevation view) . . . . . . . . . . . . . . . . . . . . 5-97
Figure 5.32
Rules of installation for discrete cable support facilities . . . . . . . . . . . . 5-99
. . . . . . . . . . . . 5-38
Figure 5.33
Raceways and fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-101
Figure 5.34
Attaching various utility columns . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-103
Figure 5.35
Perimeter raceway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-112
Figure 5.36
Molding raceway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-113
Figure 5.37
Side-reach telephones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-121
Figure 5.38
Forward-reach telephones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-122
Figure 5.39
International teletypewriter/text telephone symbol and volume
control telephone symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-124
Chapter 6: ICT Cables and Connecting Hardware
Figure 6.1
Balanced twisted-pair cable construction types . . . . . . . . . . . . . . . . . . . 6-6
Figure 6.2
Examples of balanced twisted-pair cables . . . . . . . . . . . . . . . . . . . . . . 6-7
Figure 6.3
Multimode optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
Figure 6.4
Singlemode optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-17
Figure 6.5
Side view of a loose-tube optical fiber cable . . . . . . . . . . . . . . . . . . . . 6-19
Figure 6.6
Loose-tube furcating harness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19
Figure 6. 7
Loose-tube optical fiber cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Figure 6.8
Tight-buffered optical fiber cable, distribution construction . . . . . . . . . . 6-21
Figure 6.9
Tight-buffered optical fiber cable, breakout construction . . . . . . . . . . . 6-22
Figure 6.10
Series-6 quad shield (screen) coaxial cable . . . . . . . . . . . . . . . . . . . . 6-24
Figure 6.11
Classification of cables and wires according to the NEC . . . . . . . . . . . . 6-30
Figure 6.12
110-style IDC connector design . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
Figure 6.13
Examples of 66-style connector designs . . . . . . . . . . . . . . . . . . . . . . . 6-37
Figure 6.14
BIX-style IDC connector design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40
Figure 6.15
Examples of LSA-style connector designs . . . . . . . . . . . . . . . . . . . . . . 6-42
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Figure 6.16
8P8C unkeyed modular plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45
Figure 6.17
8P8C modular plugs for stranded and solid conductors . . . . . . . . . . . . 6-46
Figure 6.18
8P8C modular jack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Figure 6.19
Modular jack design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Figure 6.20
Eight-position jack pin/pair assignments (front view) . . . . . . . . . . . . . 6-49
Figure 6.21
50-position miniature ribbon connector . . . . . . . . . . . . . . . . . . . . . . . 6-51
Figure 6.22
50-position miniature ribbon connector design . . . . . . . . . . . . . . . . . . 6-52
Figure 6.23
Telecommunications outlet/connectors . . . . . . . . . . . . . . . . . . . . . . . . 6-55
Figure 6.24
Examples of work area telecommunications outlet designs . . . . . . . . . . 6-56
Figure 6.25
Rack-mount
Figure 6.26
Modular patch panel with cable management bar installed in an
~483 mm (19 in) equipment rack . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-59
Figure 6.27
66-style block, 89-style mounting brackets, and a distribution
frame with installed 66-style blocks . . . . . . . . . . . . . . . . . . . . . . . . . 6-61
~483
mm (19 in) modular patch panel . . . . . . . . . . . . . . 6-57
Figure 6.28
110-style wiring blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
Figure 6.29
BIX-style connecting blocks mounted in a distribution frame ........ 6-66
Figure 6.30
25-pair BIX-style connecting strip . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-67
Figure 6.31
LSA-style connecting blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-68
Figure 6.32
10-pair LSA-style connecting block . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69
Figure 6.33
Hybrid equipment cord assembly or hybrid patch cord assembly ...... 6-71
Figure 6.34
Example of MS2 and Type 710 IDC connector splicing contacts ....... 6-73
Figure 6.35
Example of single-pair splice connectors and modules . . . . . . . . . . . . . 6-74
Figure 6.36
Example of multipair splice connectors and modules . . . . . . . . . . . . . . 6-75
Figure 6.37
LC-style optical fiber adapters and connectors . . . . . . . . . . . . . . . . . . 6-80
Figure 6.38
SC-style optical fiber adapters and connectors . . . . . . . . . . . . . . . . . . 6-81
Figure 6.39
ST-style optical fiber connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Figure 6.40
Array-style optical fiber connector and adapter (example of
Type-A MPO configuration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-84
Figure 6.41
Array-style optical fiber connector and adapter (example of
Type-B MPO configuration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-84
Figure 6.42
Fusion splicer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-85
Figure 6.43
Mechanical splice open position . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-86
Figure 6.44
Optical fiber pigtail splicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87
Figure 6.45
Cross-connection of optical fiber cabling segments (first- and
second-level backbone) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-90
Figure 6.46
Interconnection of equipment to backbone cabling . . . . . . . . . . . . . . . 6-91
Figure 6.47
Hybrid optical fiber patch cord assembly . . . . . . . . . . . . . . . . . . . . . . 6-92
Figure 6.48
BNC-style connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-95
Figure 6.49
BNC-style connector components . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-96
Figure 6.50
BNC-style connector plug and jack . . . . . . . . . . . . . . . . . . . . . . . . . . 6-96
Figure 6.51
50-ohm and 75-ohm bayonet BNC-style connectors . . . . . . . . . . . . . . 6-97
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Figure 6.52
One-piece crimp-style F-style connector . . . . . . . . . . . . . . . . . . . . . . 6-99
Figure 6.53
N-style coaxial connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-101
Figure 6.54
Standard wall-mount multimedia and modular furniture
multimedia outlets featuring F-style coaxial connectors . . . . . . . . . . . 6-103
Figure 6.55
BNC-style bracket mount and F-style ~483 mm (19 in) rack-mount
coaxial patch panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-105
Chapter 7: firestop Systems
Figure 7.1
Standard time/temperature curves up to three hours
Figure 7.2
Elastomeric modules (within frames) . . . . . . . . . . . . . . . . . . . . . . . . . 7-20
Figure 7.3
Mechanical firestop system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21
Figure 7.4
Example of fire-rated pathway device . . . . . . . . . . . . . . . . . . . . . . . . 7-22
Figure 7.5
Typical plastic pipe device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24
Figure 7.6
Typical cast-in-place firestop device . . . . . . . . . . . . . . . . . . . . . . . . . 7-25
Figure 7.7
Examples of poke-thru . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-26
Figure 7.8
Continuous conduit penetration through concrete . . . . . . . . . . . . . . . . 7-32
Figure 7.9
Cable penetration in concrete wall or floor . . . . . . . . . . . . . . . . . . . . . 7-33
Figure 7.10
PVC innerduct penetration in concrete wall . . . . . . . . . . . . . . . . . . . . . 7-33
Figure 7.11
PVC innerduct penetration in concrete floor . . . . . . . . . . . . . . . . . . . . 7-34
Figure 7.12
Qualified cable tray seal system in concrete wall . . . . . . . . . . . . . . . . . 7-35
Figure 7.13
Qualified steel pipe system in framed wall . . . . . . . . . . . . . . . . . . . . . 7-36
Figure 7.14
Telecommunications cable seal system for framed wall . . . . . . . . . . . . 7-37
Figure 7.15
Non-metallic innerduct penetration of framed wall . . . . . . . . . . . . . . . 7-38
Figure 7.16
Sleeve systems for retrofit over existing cables . . . . . . . . . . . . . . . . . 7-39
Figure 7.17
Sleeve system with cable tray . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-40
Figure 7.18
Sleeve system with cable support . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-40
Figure 7.19
Expansion joint or slot in a floor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49
Figure 7.20
Expansion joint or slot in a wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-50
Figure 7.21
Perimeter gap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-50
Figure 7.22
Seal system in a curtain wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-51
Figure 7.23
Typical label for all firestops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-53
Figure 7.24
Concrete floor or wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-55
Figure 7.25
Typical framed wall penetration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-56
Figure 7.26
Typical concrete wall penetration . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-57
Figure 7.27
Concrete wall or floor (metallic pipes) . . . . . . . . . . . . . . . . . . . . . . . . 7-58
Figure 7.28
Concrete wall or floor (no penetrating item) . . . . . . . . . . . . . . . . . . . . 7-59
Figure 7.29
Concrete wall or floor (electrical power, telecommunications, and
building signaling cables) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-60
Figure 7.30
Concrete floor (electrical power and telecommunications cables) ..... 7-61
Figure 7.31
Framed wall (steel pipes or conduit) . . . . . . . . . . . . . . . . . . . . . . . . . 7-62
Figure 7.32
Framed wall (cable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-63
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Figure 7.33
Framed wall (steel or aluminum cable trays) . . . . . . . . . . . . . . . . . . . 7-64
Figure 7.34
Concrete wall (cable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-65
Figure 7.35
Concrete floor or wall (bus duct) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-66
Figure 7.36
Concrete floor or wall (steel pipe) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-67
Figure 7.37
Framed wall (cables) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-68
Figure 7.38
Framed wall (PVC pipe [closed or vented]) . . . . . . . . . . . . . . . . . . . . . 7-69
Figure 7.39
Floor or wall (PVC, CPVC, or PB pipe [closed or vented] or RNC) ...... 7-70
Figure 7.40
Wood joist floor (steel or copper pipe) . . . . . . . . . . . . . . . . . . . . . . . . 7-72
Figure 7.41
Concrete floor or wall (electrical power, building signaling, control,
and telecommunications cables) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-73
Figure 7.42
Concrete floor or wall (steel or aluminum cable tray) . . . . . . . . . . . . . . 7-74
Figure 7.43
Framed wall (steel or aluminum cable tray) . . . . . . . . . . . . . . . . . . . . 7-75
Figure 7.44
Floor or wall (steel or aluminum cable tray) . . . . . . . . . . . . . . . . . . . . 7-76
Figure 7.45
Floor or wall (pipes and cable tray) . . . . . . . . . . . . . . . . . . . . . . . . . . 7-77
Figure 7.46
Head of wall joint (framed wall or concrete, fluted deck) . . . . . . . . . . . 7-78
Figure 7.47
Head of wall joint (concrete wall or concrete fluted deck) . . . . . . . . . . . 7-79
Figure 7.48
Concrete floor or wall (telecommunications cable) . . . . . . . . . . . . . . . 7-80
Figure 7.49
Framed wall (telecommunications cable) . . . . . . . . . . . . . . . . . . . . . . 7-81
Figure 7.50
Framed wall (telecommunications cable with sleeve) . . . . . . . . . . . . . . 7-82
Figure 7.51
Framed wall (telecommunications cable with firestop wrap strip) ..... 7-83
Figure 7.52
Concrete floor or wall (telecommunications cable with sleeve) ....... 7-84
Figure 7.53
Concrete floor or wall (telecommunications cable with firestop collar) .. 7-85
Figure 7.54
Framed wall stud cavity (electrical outlet box) . . . . . . . . . . . . . . . . . . 7-86
Figure 7.55
Concrete floor or wall (no penetrating item) . . . . . . . . . . . . . . . . . . . . 7-87
Figure 7.56
Concrete floor or wall (PVC innerduct or ENT with optical fiber
cables and firestop wrap strip) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-88
Figure 7.57
Concrete floor or wall (PVC innerduct or ENT with optical fiber cables
and firestop sealant) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-89
Figure 7.58
Framed wall (non-metallic conduit) . . . . . . . . . . . . . . . . . . . . . . . . . . 7-90
Figure 7.59
Framed wall (electrical power, building signaling, control, or
telecommunications cable steel sleeve system) . . . . . . . . . . . . . . . . . 7-91
Figure 7.60
Framed wall (electrical power, building signaling, control, or
telecommunications cable split sleeve system) . . . . . . . . . . . . . . . . . . 7-93
Figure 7.61
Plenum-rated wrap system for combustible pipe . . . . . . . . . . . . . . . . . 7-95
Figure 7.62
Intumescent blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-96
Figure 7.63
Framed wall (electrical power, building signaling, control, or
telecommunications cable steel sleeve system) . . . . . . . . . . . . . . . . . 7-97
Figure 7.64
Concrete floor or wall (electrical power, building signaling, control,
or telecommunications cable steel sleeve system) . . . . . . . . . . . . . . . . 7-98
Figure 7.65
Framed wall (power, building signaling, control, or
telecommunications split cable pathway system) . . . . . . . . . . . . . . . . 7-99
Figure 7.66
Framed wall (power, building signaling, control, or
telecommunications cable sleeve device system) . . . . . . . . . . . . . . . 7-100
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Figure 7.67
Concrete floor (power, building signaling, control, or
telecommunications cable sleeve system) . . . . . . . . . . . . . . . . . . . . 7-101
Figure 7.68
Framed wall (telecommunications cable steel sleeve membrane
penetration system) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-102
Figure 7.69
Framed wall (telecommunications cable firestop grommet
membrane penetration system) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-103
Figure 7. 70
Framed wall (telecommunications cable firestop grommet
penetration system) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-104
Figure 7. 71
Typical perimeter fire barrier system exterior insulation glass panel
curtain wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-105
Figure 7.72
Typical framed wall HVAC duct . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-106
Figure 7. 73
Concrete floor (power, building signaling, control, or
telecommunications cable pathway system) . . . . . . . . . . . . . . . . . . . 7-107
Chapter 8: Bonding and Grounding (Earthing)
Figure 8.1
Typical supplementary bonding grid . . . . . . . . . . . . . . . . . . . . . . . . . 8-11
Figure 8.2
Small systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14
Figure 8.3
Recommended large system arrangement . . . . . . . . . . . . . . . . . . . . . 8-16
Figure8.4
TypicaiPBB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-17
Figure 8.5
Typical SBB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
Figure 8.6
Equipment rack bonding and grounding (earthing) . . . . . . . . . . . . . . . 8-24
Figure 8. 7
Zone of protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27
Figure 8.8
Cone of protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27
Figure 8.9
Extending zone of protection
8-28
Chapter 9: Power Distribution
Figure 9.1
Measuring amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2
Figure 9.2
Measuring phase difference in a three-phase system . . . . . . . . . . . . . . . 9-3
Figure 9.3
Delta configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
Figure 9.4
Wye configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
Figure 9.5
Center-tapped single-phase configuration . . . . . . . . . . . . . . . . . . . . . . 9-5
Figure 9.6
Typical electrical power system 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Figure 9. 7
Typical electrical power system 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
Figure 9.8
Calculation chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7
Figure 9.9
Voltage and current in phase (resistive load) . . . . . . . . . . . . . . . . . . . . 9-9
Figure 9.10
Current lags voltage (inductive circuit) . . . . . . . . . . . . . . . . . . . . . . . . 9-9
Figure 9.11
Current leads voltage (capacitive load) . . . . . . . . . . . . . . . . . . . . . . . 9-10
Figure 9.12
Panelboard connection to equipment . . . . . . . . . . . . . . . . . . . . . . . . . 9-26
Figure 9.13
PDU connection to equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27
Figure 9.14
Sample Class 1 electrical system topology . . . . . . . . . . . . . . . . . . . . . 9-32
Figure 9.15
Sample Class 2 electrical system topology . . . . . . . . . . . . . . . . . . . . . 9-33
Figure 9.16
Sample Class 3 electrical system topology . . . . . . . . . . . . . . . . . . . . . 9-34
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Figure 9.17
Sample Class 4 electrical system topology . . . . . . . . . . . . . . . . . . . . . 9-35
Figure 9.18
UPS module with maintenance bypass . . . . . . . . . . . . . . . . . . . . . . . . 9-42
Figure 9.19
UPS system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-43
Figure 9.20
Parallel redundant UPS system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-44
Figure 9.21
Isolated redundant UPS system . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-45
Figure 9.22
Distributed redundant UPS system . . . . . . . . . . . . . . . . . . . . . . . . . . 9-46
Figure 9.23
Communications link UPS system . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-47
Figure 9.24
Series configured rotary UPS system . . . . . . . . . . . . . . . . . . . . . . . . . 9-48
Figure 9.25
Elevation of modular UPS system . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-50
Figure 9.26
Typical de power system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-52
Figure 9.27
Identification by color, letter, or marking . . . . . . . . . . . . . . . . . . . . . . 9-78
Chapter 10: Telecommunications Administration
Figure 10.1
Telecommunications administration systems . . . . . . . . . . . . . . . . . . . 10-1
Figure 10.2
Numbering TRs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13
Figure 10.3
Numbering cable trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-15
Figure 10.4
Patch panel labeling within a rack . . . . . . . . . . . . . . . . . . . . . . . . . . 10-18
Figure 10.5
Twisted-pair patch panel labeling with six-port groupings and nearand far-end panel and port identifiers . . . . . . . . . . . . . . . . . . . . . . . 10-19
Figure 10.6
Pair patch panel labeling example where available label space is
limited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-19
Figure 10.7
Optical fiber patch panel labeling using sequential port numbering
identifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-20
Figure 10.8
Optical fiber patch panel labeling with subpanel cassette identifiers . . 10-20
Figure 10.9
Optical fiber patch panel labeling with HDA identifiers . . . . . . . . . . . . 10-21
Figure 10.10 Labeling example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-27
Figure 10.11 Recordkeeping system example . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-35
Figure 10.12 Room grid coordinate example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-39
Figure 10.13 Sample rack and cabinet non-grid identifiers
10-41
Chapter 11: Field Testing of Structured Cabling
Figure 11.1
Wire map testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2
Figure 11.2
Pair electrical lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
Figure 11.3
Propagation delay/delay skew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
Figure 11.4
Return loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Figure 11.5
NEXT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-6
Figure 11.6
ACR-F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7
Figure 11.7
PSNEXT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-7
Figure 11.8
Coaxial TOR test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-10
Figure 11.9
Typical work area three-connector channel. . . . . . . . . . . . . . . . . . . . 11-11
Figure 11.10 Typical work area four-connector channel . . . . . . . . . . . . . . . . . . . . 11-11
Figure 11.11 Typical data center four-connector channel . . . . . . . . . . . . . . . . . . . 11-12
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Figure 11.12 Work area three-connector permanent link . . . . . . . . . . . . . . . . . . . 11-12
Figure 11.13 Work area four-connector permanent link . . . . . . . . . . . . . . . . . . . . 11-13
Figure 11.14 Data center four-connector permanent link . . . . . . . . . . . . . . . . . . . 11-14
Figure 11.15 MPTL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15
Figure 11.16 OTDR display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-21
Chapter 12: Outside Plant
Figure 12.1
Underground pathway plan
12-2
Figure 12.2
Direct-buried pathway plan
12-4
Figure 12.3
Installing underground entrances . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8
Figure 12.4
Examples of building attachment . . . . . . . . . . . . . . . . . . . . . . . . . . 12-11
Figure 12.5
Vertical conduit mast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-12
Figure 12.6
Cable entrance sleeve through a wall . . . . . . . . . . . . . . . . . . . . . . . 12-14
Figure 12.7
Typical joint trenching dimensions (section view through trench) . . . . 12-29
Figure 12.8
Positioning conduit on poles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-37
Figure 12.9
Typical cable MH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-39
Figure 12.10 Basic MH configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-40
Figure 12.11 MH Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-41
Figure 12.12 Typical MH diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-43
Figure 12.13 Typical MH on private property . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-44
Chapter 13: Audiovisual Systems
Figure 13.1
Measuring wavelength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-2
Figure 13.2
Different amplitudes of equal frequency sine waves . . . . . . . . . . . . . . 13-3
Figure 13.3
Equal amplitudes of different frequency sine waves . . . . . . . . . . . . . . . 13-3
Figure 13.4
Two waves offset by 180 degrees . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-4
Figure 13.5
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-5
Figure 13.6
Complex waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-6
Figure 13.7
Building complex waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-7
Figure 13.8
Electromagnetic spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-7
Figure 13.9
Sample rate the size of the signal frequency . . . . . . . . . . . . . . . . . . 13-12
Figure 13.10 Sample rate double the size of the signal frequency . . . . . . . . . . . . . 13-13
Figure 13.11 Video signal building blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-16
Figure 13.12 Video signal bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-17
Figure 13.13 Analog video signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-20
Figure 13.14 RF signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-21
Figure 13.15 Examples of DVI connectors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-22
Figure 13.16 Example of HDMI connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-23
Figure 13.17 Example of a DisplayPort connector. . . . . . . . . . . . . . . . . . . . . . . . . 13-24
Figure 13.18 Optimum and acceptable viewing areas . . . . . . . . . . . . . . . . . . . . . . 13-32
Figure 13.19 Sightlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-33
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Figure 13.20 Flat floor-seats aligned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-34
Figure 13.21 Tiered floor-seats staggered . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-35
Figure 13.22 Chain of typical audio components . . . . . . . . . . . . . . . . . . . . . . . . . . 13-43
Figure 13.23 Example of horn installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-45
Figure 13.24 Potential versus needed acoustic gain measurements . . . . . . . . . . . . . 13-47
Figure 13.25 Loudspeaker dispersion polar plot . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-49
Figure 13.26 Loudspeaker coverage formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-50
Figure 13.27 Typical audioconferencing system . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-55
Figure 13.28 Conference room microphone pickup pattern . . . . . . . . . . . . . . . . . . . 13-58
Figure 13.29 Two connected rooms and their acoustic echo cancellers . . . . . . . . . . . 13-61
Figure 13.30 Telephone hybrid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-63
Figure 13.31 Line echo canceller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-64
Figure 13.32 Loudspeaker coverage angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-66
Figure 13.33 Microphone pickup and loudspeaker coverage patterns . . . . . . . . . . . . 13-68
Figure 13.34 FOV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-73
Figure 13.35 Camera bright-to-dark ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-74
Figure 13.36 Videoconference light setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-75
Figure 13.37 Hexagonal loudspeaker pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-85
Figure 13.38 Square loudspeaker pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-86
Figure 13.39 70 V loudspeaker line loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-89
Figure 13.40 Distributed amplifier system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-91
Figure 13.41 Collaboration of component technology . . . . . . . . . . . . . . . . . . . . . . . 13-97
Figure 13.42 Home run network design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-103
Figure 13.43 Trunk and tap design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-104
Figure 13.44 Video over balanced twisted-pair cabling . . . . . . . . . . . . . . . . . . . . . 13-104
Figure 13.45 Video over optical fiber cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-105
Figure 13.46 Dividing the optical signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-106
Figure 13.47 Signal tilt for
~12.7
mm (0.50 in) hardline . . . . . . . . . . . . . . . . . . . . 13-107
Chapter 14: Building Automation Systems
Figure 14.1
Building system changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-3
Figure 14.2
Example of fire alarm, security, and access control interfaces with BAS. 14-6
Figure 14.3
HVAC system in a small commercial building . . . . . . . . . . . . . . . . . . . 14-9
Figure 14.4
Hierarchical configuration of processor and controller levels . . . . . . . . . 14-18
Figure 14.5
Cabling system elements and channel . . . . . . . . . . . . . . . . . . . . . . . . 14-30
Figure 14.6
Single-point and chained branch devices . . . . . . . . . . . . . . . . . . . . . . 14-31
Figure 14.7
Cabling system topologies for BAS . . . . . . . . . . . . . . . . . . . . . . . . . . 14-37
Figure 14.8
Devices bridged at HC (FD) or HCP . . . . . . . . . . . . . . . . . . . . . . . . . . 14-38
Figure 14.9
Devices chained at the HC (FD) or HCP . . . . . . . . . . . . . . . . . . . . . . . 14-39
Figure 14.10 BAS equipment cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-42
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Figure 14.11 Traditional distributed BAS with multiple horizontal pathways. . . . . . . 14-43
Figure 14.12 Integrated distributed BAS with single horizontal pathway. . . . . . . . . 14-44
Figure 14.13 Separate and consolidated cabling systems . . . . . . . . . . . . . . . . . . . 14-46
Figure 14.14 Reducing quantity and costs of BAS controllers . . . . . . . . . . . . . . . . . 14-48
Chapter 15: Data Networks
Figure 15.1
Example of a LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2
Figure 15.2
Example of a WAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3
Figure 15.3
OSI Reference Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5
Figure 15.4
Message transfer described using the OSI Reference Model . . . . . . . . . 15-7
Figure 15.5
Multiple routers in an internetwork . . . . . . . . . . . . . . . . . . . . . . . . . 15-11
Figure 15.6
Integrated VoiP infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-16
Figure 15.7
Types of network video communications . . . . . . . . . . . . . . . . . . . . . 15-17
Figure 15.8
Functional (top-down) design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-19
Figure 15.9
Physical (bottom-up) design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-20
Figure 15.10 Class 1 telecommunications infrastructure . . . . . . . . . . . . . . . . . . . . 15-22
Figure 15.11 Class 2 telecommunications infrastructure . . . . . . . . . . . . . . . . . . . . 15-22
Figure 15.12 Class 3 telecommunications infrastructure . . . . . . . . . . . . . . . . . . . . 15-23
Figure 15.13 Class 4 telecommunications infrastructure . . . . . . . . . . . . . . . . . . . . 15-24
Figure 15.14 Server-to-switch connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-25
Figure 15.15 Redundant server-to-switch connections . . . . . . . . . . . . . . . . . . . . . 15-26
Figure 15.16 Server-to-storage director connections . . . . . . . . . . . . . . . . . . . . . . 15-27
Figure 15.17 Redundant server-to-storage director connections . . . . . . . . . . . . . . 15-28
Figure 15.18 Example of Class 3 and Class 4 network and storage infrastructure. . . 15-29
Figure 15.19 Centralized data center topology. . . . . . . . . . . . . . . . . . . . . . . . . . . 15-30
Figure 15.20 End-of-row data center topology . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-31
Figure 15.21 Top-of-rack data center topology . . . . . . . . . . . . . . . . . . . . . . . . . . 15-32
Figure 15.22 Example of campus network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-33
Figure 15.23 Links from customer site to SP. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-35
Figure 15.24 Example of a centralized WAN design . . . . . . . . . . . . . . . . . . . . . . . 15-37
Figure 15.25 Example of a partial mesh WAN design . . . . . . . . . . . . . . . . . . . . . . 15-38
Figure 15.26 Partial mesh WAN after a link failure . . . . . . . . . . . . . . . . . . . . . . . . 15-39
Figure 15.27 Example of a full mesh WAN design
15-40
Chapter 16: Wireless Networks
Figure 16.1
Frequency, amplitude, and wavelength . . . . . . . . . . . . . . . . . . . . . . . 16-6
Figure 16.2
Propagation velocity through free space . . . . . . . . . . . . . . . . . . . . . . . 16-7
Figure 16.3
Fresnel zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-8
Figure 16.4
Ground and sky waves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-11
Figure 16.5
Isotropic gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-12
Figure 16.6
Amplitude modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-14
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Figure 16.7
Frequency modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-15
Figure 16.8
Phase modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-16
Figure 16.9
Pulse modulation techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-17
Figure 16.10 Harmonic distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-19
Figure 16.11 Power injector with tower-mounted preamplifier. . . . . . . . . . . . . . . . 16-35
Figure 16.12 Power injector for WLAN AP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-36
Figure 16.13 Typical DAS environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-40
Figure 16.14 Omnidirectional antennas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-42
Figure 16.15 Directional antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-43
Figure 16.16 Radiating cable standoff mount. . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-46
Figure 16.17 Headend and backend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-50
Figure 16.18 Optical to RF coupling power relationship. . . . . . . . . . . . . . . . . . . . . 16-52
Figure 16.19 ESS using a wireless distribution system . . . . . . . . . . . . . . . . . . . . . 16-70
Figure 16.20 ESS using a cable distribution system . . . . . . . . . . . . . . . . . . . . . . . 16-71
Figure 16.21 PTP bridging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-74
Figure 16.22 Point-to-multipoint bridging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-75
Figure 16.23 Repeating bridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-76
Chapter 17: Electronic Safety and Security
Figure 17.1
Elements of a security program . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-2
Figure 17.2
Threat, risk, and vulnerability assessments . . . . . . . . . . . . . . . . . . . . 17-3
Figure 17.3
Security quandary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-4
Figure 17.4
MPTL with one CP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-12
Figure 17.5
Electric strikes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-15
Figure 17.6
Magnetic locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-17
Figure 17.7
Electric locksets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-18
Figure 17.8
Electric latch and mechanical operation . . . . . . . . . . . . . . . . . . . . . . 17-19
Figure 17.9
Electrified exit hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-20
Figure 17.10 Grid display layouts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-25
Figure 17.11 Typical fire alarm pull station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-34
Figure 17.12 Example of a Class N pathway . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-42
Figure 17.13 Redundant cables in Class N pathways . . . . . . . . . . . . . . . . . . . . . . 17-43
Figure 17.14 Additional pathway between Switch 1 and 2 . . . . . . . . . . . . . . . . . . . 17-44
Figure 17.15 Endpoint servicing more than one device. . . . . . . . . . . . . . . . . . . . . 17-44
Figure 17.16 Enhanced annunciator panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-54
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Chapter 18: Data Centers
Figure 18.1
Relationship of spaces in a data center . . . . . . . . . . . . . . . . . . . . . . . 18-2
Figure 18.2
Hierarchical structure of a data center from CENELEC EN 50173-5
and ISO/IEC 11801-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-14
Figure 18.3
Example of TIA-942-B data center topology . . . . . . . . . . . . . . . . . . . 18-15
Figure 18.4
Cabling cross-sectional area comparison . . . . . . . . . . . . . . . . . . . . . 18-16
Figure 18.5
Example of equipment cabling using overhead infrastructure ....... 18-19
Figure 18.6
Example of overhead communications cabling with power and
bonding conductors beneath raised access floor . . . . . . . . . . . . . . . . 18-21
Figure 18.7
Example of communications, power, and earth conductors installed
in raised access floor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-22
Figure 18.8
Layering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-26
Chapter 19: Health Care
Figure 19.1
TDR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-5
Figure 19.2
Redundancy option 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-6
Figure 19.3
Redundancy option 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-7
Figure 19.4
Redundancy option 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-8
Figure 19.5
Redundancy option 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-9
Figure 19.6 Typical nurse call staff emergency station . . . . . . . . . . . . . . . . . . . . 19-12
Figure 19.7
Typical nurse call bedside station . . . . . . . . . . . . . . . . . . . . . . . . . . 19-13
Figure 19.8
Typical nurse call code call station . . . . . . . . . . . . . . . . . . . . . . . . . . 19-14
Figure 19.9
Typical nurse call staff station . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-15
Figure 19.10 Nurse call system traditional one-line diagram . . . . . . . . . . . . . . . . . 19-18
Figure 19.11 Typical physiological monitor remote wiring diagram . . . . . . . . . . . . . 19-29
Figure 19.12 Typical RFID tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-31
Figure 19.13 Typical IPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-36
Chapter 20: Residential Cabling
Figure 20.1
Residential cabling layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-4
Figure 20.2
Media room with one balanced twisted-pair and three coaxial cable
runs to a telecommunications outlet . . . . . . . . . . . . . . . . . . . . . . . . . 20-9
Figure 20.3
Example of a residential premises cabling system . . . . . . . . . . . . . . . 20-10
Figure 20.4
Multi-dwelling unit cabling layout . . . . . . . . . . . . . . . . . . . . . . . . . . 20-12
Figure 20.5
Telecommunications backbone and distribution cabling layout for an
apartment building with a central backbone . . . . . . . . . . . . . . . . . . . 20-13
Figure 20.6
Telecommunications backbone and distribution cabling layout for an
apartment building with multiple backbones. . . . . . . . . . . . . . . . . . . 20-14
Figure 20.7
Example of conduit distribution for a seven-unit townhouse ........ 20-15
Figure 20.8
Cabling distribution for a side-by-side duplex residence . . . . . . . . . . . 20-16
Figure 20.9
Example of cable distribution for frame apartment projects ........ 20-17
Figure 20.10 Example of an apartment complex with backbone cable . . . . . . . . . . 20-18
Figure 20.11 Telecommunications outlets/connectors. . . . . . . . . . . . . . . . . . . . . . 20-23
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Chapter 21: Project Administration and Execution
Figure 21.1
Simple OBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-17
Figure 21.2
PERT or network logic diagram using the precedence diagram
method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-21
Figure 21.3
Milestone chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-21
Figure 21.4
Gantt chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-22
Figure 21.5
Calendar of schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-22
Figure 21.6
Example of budgeted cost of work schedules . . . . . . . . . . . . . . . . . . 21-25
Figure 21.7
Example of plotted BCWP, BCWS, and ACWP . . . . . . . . . . . . . . . . . . 21-25
Figure 21.8
Client/supplier model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-27
Figure 21.9
United States National CAD Standard@ layer name format . . . . . . . . . 21-53
Chapter 22: Special Design Considerations
Figure 22.1
Industrial floor area described by MICE classification 1, 2, or 3 ....... 22-6
Appendix A: Codes, Standards, Regulations, and Organizations
Figure A.1
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Conformite europeenne (CE) mark . . . . . . . . . . . . . . . . . . . . . . . . . . A-82
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Tables
Chapter 1: Principles of Transmission
Table 1.1
Conductor descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Table 1.2
Solid conductor properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Table 1.3
Electrical characteristics of common insulation types . . . . . . . . . . . . . . . 1-7
Table 1.4
Explanations of insulation electrical characteristics . . . . . . . . . . . . . . . . 1-8
Table 1.5
Types of cable shields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Table 1.6
Common units of frequency measurement . . . . . . . . . . . . . . . . . . . . . 1-18
Table 1.7
Spectrums of standard frequency bands . . . . . . . . . . . . . . . . . . . . . . 1-20
Table 1.8
Power ratios from 0 to 60 dB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
Table 1.9
Transmission data rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Table 1.10
Coding methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-35
Table 1.11
ADSL standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-43
Table 1.12
ADSL performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-44
Table 1.13
VDSL data rate and target range . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-44
Table 1.14
Propagation delay/delay skew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-55
Table 1.15
Balanced twisted-pair cabling channel performance . . . . . . . . . . . . . . . 1-64
Table 1.16
Applications supported using 100-ohm balanced twisted-pair cabling .. 1-65
Table 1.17
Media selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 7
Table 1.18
Transmission, speed, distance, and pair requirements . . . . . . . . . . . . . 1-69
Table 1.19
IEEE 802.3 PoE classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-76
Table 1.20
Characteristics of typical LED sources . . . . . . . . . . . . . . . . . . . . . . . . 1-83
Table 1.21
Characteristics of typical short wavelength laser . . . . . . . . . . . . . . . . . 1-84
Table 1.22
Characteristics of typical VCSELs . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-85
Table 1.23
Characteristics of typical LD sources . . . . . . . . . . . . . . . . . . . . . . . . . 1-86
Table 1.24
Comparison of transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-87
Table 1.25
Optical fiber cable performance by type . . . . . . . . . . . . . . . . . . . . . . . 1-90
Table 1.26
Summarized comparison of core sizes of multimode and
singlemode optical fiber cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-98
Table 1.27
Typical characteristics of multi mode optical fiber . . . . . . . . . . . . . . . . . 1-99
Table 1.28
Characteristics of 50/125 !Jm multimode optical fiber . . . . . . . . . . . . 1-100
Table 1.29
Characteristics of 62.5/125 1-1m multimode optical fiber . . . . . . . . . . . 1-101
Table 1.30
Typical characteristics of singlemode optical fiber . . . . . . . . . . . . . . . 1-102
Table 1.31
Maximum cable attenuation coefficient . . . . . . . . . . . . . . . . . . . . . . 1-104
Table 1.32
Mismatch of core size and power loss . . . . . . . . . . . . . . . . . . . . . . . 1-106
Table 1.33
Calculating optical fiber performance . . . . . . . . . . . . . . . . . . . . . . . . 1-108
Table 1.34
System gain, power penalties, and link loss budget calculations . . . . . 1-111
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Table 1.35
Calculating losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-112
Table 1.36
Splice loss values in decibels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-113
Table 1.37
Minimum system loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-114
Table 1.38
Common SONET and SDH transmission rates . . . . . . . . . . . . . . . . . . 1-117
Table 1.39
Levels of multiplexing and carrier transmission in North America .... 1-123
Table 1.40
Levels of multiplexing and carrier transmission in Europe
1-125
Chapter 2: Electromagnetic Compatibility
Table 2.1
Factors that can affect EMI in telecommunications equipment
Table 2.2
2-12
Factors that can affect EMI in sites . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Table 2.3
Four levels of immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
Table 2.4
ESD susceptibility ranges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
Table 2.5
Mutual capacitance ranges for telecommunications cables . . . . . . . . . . 2-21
Table 2.6
Minimum separation distances from possible sources of EMI
exceeding 5 kVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
Table 2.7
Separation requirements between metallic cabling and specific EMI
sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
Chapter 3: Telecommunications Spaces
Table 3.1
Size guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Table 3.2
Smaller buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Table 3.3
Allocating termination space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Table 3.4
Layout considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Chapter 4: Backbone Distribution Systems
Table 4.1
Backbone distribution system components . . . . . . . . . . . . . . . . . . . . . . 4-1
Table 4.2
EFM installed singlemode optical fiber . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Table 4.3
Common conduit sizes with vernacular . . . . . . . . . . . . . . . . . . . . . . . 4-41
Table 4.4
Summary of EFM physical layer signaling systems . . . . . . . . . . . . . . . 4-54
Chapter 5: Horizontal Distribution Systems
Table 5.1
Maximum allowable cable lengths with the use of multiuser
telecommunications outlet assemblies. . . . . . . . . . . . . . . . . . . . . . . . 5-28
Table 5.2
Comparison of CP locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Table 5.3
PoE and HDBaseT current specifications . . . . . . . . . . . . . . . . . . . . . . . 5-37
Table 5.4
Primary PON variations and their source standards . . . . . . . . . . . . . . . 5-57
Table 5.5
Maximum channel attenuation and supported distance for PON
versions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-60
Table 5.6
EMT 40 percent conduit fill rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-74
Table 5. 7
Typical EMT conduit fill rate for varying cable diameters. . . . . . . . . . . . 5-75
Table 5.8
Conduit fill with 1 bend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-76
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Table 5.9
Conduit fill with 2 bends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-77
Table 5.10
Bend radii guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-80
Table 5.11
Adapting designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-81
Table 5.12
Typical space requirements for pull boxes having conduit enter at
opposite ends of the box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-83
Table 5.13
Slip sleeves and gutters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-84
Table 5.14
Coverings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-90
Table 5.15
Load capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-90
Table 5.16
Guidelines for recommending ceiling panels . . . . . . . . . . . . . . . . . . . . 5-94
Table 5.17
Common types of cable trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-105
Table 5.18
Common cable tray dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-107
Table 5.19
ADA height requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-120
Chapter 6: ICT Cables and Connecting Hardware
Table 6.1
Comparison of the terms class and category within ISO/IEC and
TIA standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Table 6.2
Balanced twisted-pair cabling channel performance . . . . . . . . . . . . . . . . 6-4
Table 6.3
Balanced twisted-pair cable designations . . . . . . . . . . . . . . . . . . . . . . . 6-4
Table 6.4
Balanced cable designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Table 6.5
Optical fiber cable transmission performance parameters . . . . . . . . . . . 6-15
Table 6.6
Typical distances supported by optical fiber cabling . . . . . . . . . . . . . . . 6-18
Table 6.7
Examples of regional fire safety standards . . . . . . . . . . . . . . . . . . . . . 6-27
Table 6.8
Communications cable types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Table 6.9
Optical fiber cable types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29
Table 6.10
Interclass relativity of NEC and IEC fire safety specifications ........ 6-31
Table 6.11
Comparison between NEC CM ratings and CSA FT requirements ...... 6-32
Table 6.12
Connecting hardware transmission performance categories for
110-style connector-based connecting hardware . . . . . . . . . . . . . . . . . 6-35
Table 6.13
Connecting hardware transmission performance categories . . . . . . . . . 6-38
Table 6.14
Connecting hardware transmission performance categories for
BIX-style connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40
Table 6.15
Connecting hardware transmission performance categories for
LSA-style connector-based connecting hardware . . . . . . . . . . . . . . . . . 6-43
Table 6.16
Modular plug transmission performance categories . . . . . . . . . . . . . . . 6-47
Table 6.17
Modular jack transmission performance categories . . . . . . . . . . . . . . . 6-50
Table 6.18
50-position miniature ribbon connector transmission performance
categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Table 6.19
Optical fiber link transmission performance calculations worksheet .... 6-78
Table 6.20
Splice insertion loss guidelines and objectives . . . . . . . . . . . . . . . . . . 6-86
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Chapter 7: Firestop Systems
Table 7.1
Barrier standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6
Table 7.2
European test standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12
Table 7.3
Rating classifications, standards, and definitions . . . . . . . . . . . . . . . . . 7-13
Table 7.4
Limiting temperature for each test standard . . . . . . . . . . . . . . . . . . . . 7-16
Table 7.5
Pipes, conduits, sleeve systems, innerducts, cable trays, and
cable penetration firestop methods (in ceilings) . . . . . . . . . . . . . . . . . 7-44
Table 7.6
Electrical apparatus, boxes, and access panels firestop methods
(in ceilings) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-45
Table 7. 7
Pipes, conduits, sleeve systems, innerducts, cable trays, and cable
penetration firestop methods (in floors/ceilings) . . . . . . . . . . . . . . . . . 7-45
Table 7.8
Underfloor pipe, conduit, sleeve system, and innerduct firestop
methods (in floors) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-46
Table 7.9
Pipe sizes and fire ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-71
Table 7.10
Sizes of pipe chokes, wrap strip layers, and fire ratings . . . . . . . . . . . . 7-91
Table 7.11
United States firestop standards. . . . . . . . . . . . . . . . . . . . . . . . . . . 7-109
Table 7.12
Canadian firestop standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-111
Table 7.13
International firestop standards . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-112
Chapter 8: Bonding and Grounding (Earthing)
Table 8.1
Telecommunications bonding component terms cross-reference ....... 8-2
Table 8.2
Basic guide to calculating bonding conductor resistance values ....... 8-21
Chapter 9: Power Distribution
Table 9.1
Electrical formulas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-14
Table 9.2
Circular mils of standard AWG conductors . . . . . . . . . . . . . . . . . . . . . 9-16
Table 9.3
Voltage and current fluctuations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
Table 9.4
K-rating based on load makeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-22
Table 9.5
Calculating maximum input current . . . . . . . . . . . . . . . . . . . . . . . . . . 9-58
Table 9.6
Calculating voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-60
Table 9.7
Major alarms (de) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-72
Table 9.8
Minor alarms (de) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-73
Table 9.9
Major alarms (UPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-73
Table 9.10
Color code for conductors in the United States . . . . . . . . . . . . . . . . . . 9-77
Table 9.11
Color code for conductors in the United Kingdom and Ireland. . . . . . . . 9-79
Chapter 10: Telecommunications Administration
Table 10.1
Required identifiers by class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-6
Table 10.2
Minimum and optional administration system elements . . . . . . . . . . . . 10-8
Table 10.3
Color codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-22
Table 10.4
Identifying pathways. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-32
Table 10.5
Required records by class. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-37
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Chapter 11: Field Testing of Structured Cabling
Table 11.1
Determining worst-case attenuation coefficient . . . . . . . . . . . . . . . . . 11-23
Chapter 12: Outside Plant
Table 12.1
Service diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-17
Table 12.2
Terminating space. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-20
Table 12.3
Vertical/horizontal separations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-28
Table 12.4
Metallic conduit types and sizes used in telecommunications . . . . . . . 12-33
Table 12.5
Direct-bury PVC conduit types and sizes used in
telecommunications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-34
Table 12.6
Non-metallic conduit types and sizes used in telecommunications .... 12-35
Chapter 13: Audiovisual Systems
Table 13.1
Color temperature ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-9
Table 13.2
Typical audio signal units of measurement . . . . . . . . . . . . . . . . . . . . 13-11
Table 13.3
Common bit resolutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-14
Table 13.4
Supported video formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-24
Table 13.5
SDTV versus HDTV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-26
Table 13.6
Front and rear projection advantages and disadvantages. . . . . . . . . . 13-41
Table 13.7
Area covered by horns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-87
Table 13.8
AI speech intelligibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-95
Table 13.9
Example of loss values per ~30.5 m (100ft) of the coaxial cable for
the lowest and highest channels in a 60-channel system .......... 13-107
Chapter 14: Building Automation Systems
Table 14.1
Typical work and BAS coverage area sizes . . . . . . . . . . . . . . . . . . . . 14-33
Chapter 16: Wireless Networks
Table 16.1
Balanced twisted-pair cabling channel performance . . . . . . . . . . . . . . 16-21
Table 16.2
Transceiver types and application . . . . . . . . . . . . . . . . . . . . . . . . . . 16-28
Chapter 18: Data Centers
Table 18.1
Comparison of the standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-10
Chapter 20: Residential Cabling
Table 20.1
Recognized tenant area residential cabling by grade . . . . . . . . . . . . . . 20-3
Table 20.2
Guidance in planning the wall space allocated for DD and
associated equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-7
Table 20.3
Telecommunications outlets/connectors for residences . . . . . . . . . . . . 20-9
Table 20.4
Minimum space for a multi-dwelling unit CTR . . . . . . . . . . . . . . . . . . 20-11
Chapter 21: Project Administration and Execution
Table 21.1
© 2020 BICSI®
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Chapter 22: Special Design Considerations
Table 22.1
List of applicable IEC test procedures . . . . . . . . . . . . . . . . . . . . . . . . 22-8
Table 22.2
IP codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-10
Table 22.3
Enclosure ratings and IP codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-11
Table 22.4
Comparison of specific applications of enclosures for indoor
non-hazardous locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-12
Appendix A: Codes, Standards, Regulations, and Organizations
Table A.1
Relationship between series EN 50174 and other design standards .... A-30
Table A.2
Sections of the Canadian Electrical Code . . . . . . . . . . . . . . . . . . . . . . A-44
Table A.3
Federal Communications Commission documents . . . . . . . . . . . . . . . . A-52
Table A.4
NESC® parts, sections, and rules applicable to telecommunications
distribution requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-54
Table A.5
NEC® 2011 chapters, articles, and sections that impact
telecommunications installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-59
Table A.6
Federal safety and health standards . . . . . . . . . . . . . . . . . . . . . . . . . A-71
Table A.7
Federal Communications Commission Regulations . . . . . . . . . . . . . . . . A-75
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Examples
Chapter 1: Principles of Transmission
Example 1.1 Optical fiber performance calculations example . . . . . . . . . . . . . . . . 1-109
Chapter 14: Building Automation Systems
Example 14.1 SoW checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-26
Chapter 21: Project Administration and Execution
Example 21.1
WBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-19
Example 21.2
WBS in a text outline format . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21-20
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Acronyms and Abbreviations
Acronyms and Abbreviations
=A
AID
analog-to-digital
A&E
architecture and engineering
ABA
Architectural Barriers Act
ac
alternating current
ACEG
alternating current equipment ground
ACK
acknowledgment
ACL
access control list
ACR
attenuation-to-crosstalk ratio
ACRF
attenuation-to-crosstalk ratio, far-end
ACS
access control system
ACWP
actual cost of work performed
ADA
Americans with Disabilities Act
ADAAG
Americans with Disabilities Act Accessibility Guidelines
ADF
area distribution facility
ADO
auxiliary disconnect outlet
ADPCM
adaptive differential pulse code modulation
ADR
alternative dispute resolution
ADSL
asymmetric digital subscriber line
ADSS
all-dielectric self-support
AEC
acoustic echo canceller
AEC
architecture, engineering, and construction
© 2020 BICSI®
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TDMM, 14th edition
Acronyms and Abbreviations
AES
advanced encryption standard
AF
audio frequency
AFEXT
alien far-end crosstalk
AFF
above finished floor
AGC
automatic gain control
AHJ
authority having jurisdiction
AHU
air handling unit
AI
analog input
AI
articulation index
AIM
automated infrastructure management
AM
amplitude modulation
AMES
architectural, mechanical, electrical, structural
AMI
alternate mark inversion
AMSL
above mean sea level
AN EXT
alien near-end crosstalk
AO
analog output
AP
access point
AP
access provider
APC
angle physical contact
API
application programming interface
AS
Australian standard
ASCII
American standard code for information interchange
ASP
authorized service provider
ATM
asynchronous transfer mode
ATM
automatic teller machine
TDMM, 14th edition
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© 2020 BICSI®
Acronyms and Abbreviations
ATR
all-threaded-rod
ATS
automatic transfer switch
AUTO NEG
autonegotiation
AV
audiovisual
AWG
American wire gauge
AWS
advanced wireless services
AXT
alien crosstalk
=B
BACnet®
building automation and control network
BAS
building automation systems
BBC
backbone bonding conductor
BBMD
BACnetqc broadcast management device
BC
bonding conductor
BCT
bonding conductor for telecommunications
BCWP
budgeted cost of work performed
BCWS
budgeted cost of work scheduled
BD
building distributor
BDA
bidirectional amplifier
BDSL
bit rate digital subscriber
BER
bit error rate
BET
building entrance tenninal
BIBB
BACnet"1 interoperability building block
BIM
building information modeling
© 2020 BICSI®
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TDMM, 14th edition
Acronyms and Abbreviations
BMS
building management system
BN
bonding network
BNC
Bayonet Neill-Concelman
BOM
bill of material
BPSK
binary phase shift keying
BRI
basic rate interface
BSC
base station controller
BSS
basic service set
BTL
BACnet@ Testing Laboratories
BTS
base transceiver station
BVLL
BACnd" virtual link layer
=C
c
chrominance signal
CAD
computer-aided design
CADD
computer-aided drafting and design
CAFM
computer-aided facility management
CAN
campus area network
CAP
carrierless amplitude and phase
CAT
category
CATV
cable TV
CBC
coupled bonding conductor
CBN
common bonding network
CBS
core bore seal
CCD
charge coupled device
TDMM, 14th edition
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© 2020 BICSI®
Acronyms and Abbreviations
CCK
complementary code keying
cct
circuit (European)
CCTV
closed-circuit TV
ccu
coronary care unit
ccu
critical care unit
cd
candela
CD
campus distributor
CD
construction document
CDF
campus distribution facility
COMA
code division multiple access
CE
common element
CE
Conformite Europeene
Consumer Electronics Bus
CENELEC
Comite Europeen de Normalisation Electrotechnique
CENTREX
central exchange
CER
common equipment room
CEV
controlled environment vault
CFR
Code ofFederal Regulations (U.S.)
CHCC
comprehensive health care clinic
C/1
carrier-to-interference ratio
CI
circuit integrity
CIA
confidentiality, integrity, and availability
CIC
CEBus11 Industry Council
en
critical infrastructure industry
© 2020 BICSI®
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TDMM, 14th edition
Acronyms and Abbreviations
CIS
common intelligibility scale
ckt
circuit (U.S.)
CLEC
competitive local exchange carrier
CM
common mode
CM
construction manager
CM
control module
CMP
communications plenum
CMR
communications riser
CMRR
common-mode rejection ratio
CMU
concrete masonry unit
CMUC
communications undercarpet
CMX
communications residential
co
central office
co
change order
CON
certificate of need
COR
close observation room
COT
central office terminal
CP
consolidation point
CPE
customer premises equipment
CPl
cost performance index
CPM
critical path method
CPU
central processing unit
CPVC
chlorinated polyvinyl chloride
CR
computer room
CRAC
computer room air conditioning
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© 2020 BICSI®
Acronyms and Abbreviations
CRC
cyclic redundancy check
CRI
color rendition index
CRO
construction ride out
CRT
cathode ray tube
CSI
Construction Specifications Institute
CSMA/CA
carrier sense multiple access with collision avoidance
CSMA/CD
carrier sense multiple access with collision detection
csu
channel service unit
CTCSS
continuous tone coded squelch system
CTR
common telecommunications room
CTS
clear to send
CUE
concrete universal enclosure
CWDM
coarse wavelength division multiplexing
=D
D/A
digital-to-analog
DA
distributed automation
DA
distribution amplifier
DAC
direct attach cable
DACR
digital alarm communicator receiver
DACS
digital alarm communicator system
DACT
digital alarm communicator transmitter
DARR
digital alarm radio receiver
DARS
digital alarm radio system
DART
digital alarm radio transmitter
© 2020 BICSI®
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TDMM, 14th edition
Acronyms and Abbreviations
DAS
direct-attached storage
DAS
distributed antenna system
DAQ
delivered audio quality
llB
design-build
dB a
A-weighted decibel
dBd
decibels relative to a half wavelength dipole
dBi
decibels relative to an isotropic radiator
DBS
direct broadcast satellite
dBu
decibel unit
de
direct current
DCIE
data center infrastructure efficiency
DCS
digital cellular system
DCS
digital coded squelch
DD
design development
DD
design document
DD
distribution device
DDC
direct digital control
DDS
dynamic digital signage
DECT
digital enhanced cordless telecommunications
DE PIC
dual expanded plastic insulated conductor
DHCP
dynamic host configuration protocol
DI
digital input
DLC
data link control
DM
differential mode
TDMM, 14th edition
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© 2020 BICSI®
Acronyms and Abbreviations
DMD
differential mode delay
DMT
discrete multitone
DMVPN
Dynamic Multipoint Virtual Private Network
IlMZ
demilitarized zone
DNR
digital noise reduction
DO
digital output
DoS
denial of service
DP
demarcation point
DS
digital signal
DS
distribution system
DSO
digital signaling level zero
DSl
digital signal level one
DS1C
digital signal level one C
DS2
digital signal level two
DS3
digital signal level three
DSL
digital subscriber line
DSP
digital signal processor
DSS
digital satellite signal
DSSS
direct sequence spread spectrum
DSU
data service unit
DSX
digital signal cross-connect
DTE
data terminal equipment
DTV
digital TV
DVB
digital video broadcast
DVD
digital versatile disc
© 2020 BICSI®
AA-9
TDMM, 14th edition
Acronyms and Abbreviations
DVI-A
digital visual interface-analog
OVI-D
digital visual interface-digital
DVI-1
digital visual interface-integrated
DVMS
digital video management system
DVR
digital video recorder
DVT
digital video technology
=E
E&O
errors and omissions
E/0
electronic-to-optical
EAC
electronic access control
Eb/NO
energy per bid to noise density ratio
EBC
equipment bonding conductor
ECTFE
ethylene chlorotrifluoroethylene
EDA
equipment distribution area
EDP
electrical distribution panel
EEA
European economic area
EESS
Earth Exploration-Satellite Service
EF
entrance
EFM
Ethernet in the first mile
EFT
electrical fast transient
EHF
extremely high frequency
EIA
Electronic Industries Alliance
EIRP
effective isotropic radiated power
EIRP
equivalent isotropic radiated power
TDMM, 14th edition
t~tcility
AA-10
© 2020 BICSI®
Acronyms and Abbreviations
ELF
extremely low frequency
ELFEXT
equal level far-end crosstalk
EM
electromagnetic
EMU
effective modal bandwidth
EMC
electromagnetic compatibility
EMI
electromagnetic interference
EMP
electromagnetic pulse
EMR
electromagnetic radiation
EMS
emergency medical service
EMS
energy management system
EMT
electrical metallic tubing
ENI
external network interface
ENT
electrical non-metallic tubing
EO
equipment outlet
EoDSL
Ethernet over digital subscriber line
EOLR
end-of-line resistor
EP
entrance point
EPO
emergency power off
EPON
Ethemet passive optical network
EPR
earth potential rise
EQ
equalizer
ER
equipment room
ERP
efiective radiated power
ERRCS
emergency responder radio coverage systems
ESD
electrostatic discharge
© 2020 BICSI®
AA-11
TDMM, 14th edition
Acronyms and Abbreviations
ESF
extended superfi·ame
ESMR
enhanced specialized mobile radio
ESN
electronic serial number
ESS
electronic security and safety
ESS
extended service set
ETSI
European Telecommunications Standards Institute
ETL
Electronic Testing Laboratories (Intertek)
EV
earned value
=F
F/UTP
foil screened with unshielded twisted-pairs
FA
fire alarm
FACP
fire alarm control panel
fax
facsimile
FC
ferrule connector
FC
fiber connector
FC
fixed connector
FCC
Federal Communications Commission
FCS
frame check sequence
FD
floor distributor
FDDI
fiber distributed data interface
FDM
frequency division multiplexing
FEC
forward error correction
FEP
fluorinated ethylene propylene
FEXT
far-end crosstalk
TDMM, 14th edition
AA-12
© 2020 BICSI®
Acronyms and Abbreviations
FHSS
frequency-hopping spread spectrum
FirstNet
First Responder Network Authority
FIT
frame interline transfer
-FLA
flooded lead acid
FLS
fire-! ife-safety
FM
frequency modulation
FMC
flexible metal conduit
FMT
flexible metallic tubing
FO
fiber optic
FO
field order
FOV
field of view
F-PDCH
forward packet data channel
FR
fire retardant
FRS
Family Radio Service
FS
factor of safety
:FS
Fixed Service
FSO
free space optics
FTC
failure to capture
FTP
file transfer protocol
FTP
foil twisted-pair
FTTH
fiber to the home
FTTO
fiber to the office
FTTx
fiber to the x
FWHM
full width half maximum
© 2020 BICSJ:®
AA-13
TDMM, 14th edition
Acronyms and Abbreviations
=G
G
conductance
GAN
global area network
GbE
Gigabit Ethernet
GC
general contractor
GE
grounding equalizer
GEC
grounding electrode conductor
GFCl
ground fault circuit interrupter
GIS
geographic information system
GMP
guaranteed maximum price
GPON
gigabit passive optical network
GPR
ground penetrating radar
GPR
ground potential rise
GSl\1
Global System fen· Mobile Communications
GUI
graphical user interface
=H
HAAT
height above average tenain
HC
horizontal cross-connect
HCP
horizontal connection point
HD
high definition
HDA
horizontal distribution area
HDMI
high-definition multimedia interface
HDPE
high density polyethylene
HDSDI
high-definition serial digital interface
TDMM, 14th edition
AA-14
© 2020 BICSI®
Acronyms and Abbreviations
HDSL
high bit-rate digital subscriber line
HDTV
high definition TV
HF
high frequency
HFC
hybrid fiber-coax
HH
handhole
HIPAA
Health Insurance Portability and Accountability Act of 1996
hostid
host identification
HR
human resources
HRJDSSS
high rate direct sequence spread spectrum
HSAB
high-speed air blown (procedure)
HSPDA
high-speed downlink packet access
HTTP
hypertext transfer protocol
HVAC
heating, ventilation, and air-conditioning
=I
1/0
input/output
I
current
I
in-phase signal
lAPP
interaccess point protocol
IB
intelligent building
IBC
International Building Code
IHN
isolated bonding network
IBSS
independent basic service set
IC
integrated circuit
IC
intermediate cross-connect
© 2020 BICSI®
AA-15
TDMM, 14th edition
Acronyms and Abbreviations
ICT
information and communications technology
ICU
intensive care unit
ID
identifier
ID
inside diameter
ID
intelligent device
ID
intermediate distributor
JDC
initiating device circuit
IDC
insulation displacement connector
IDF
intermediate distribution frame
IDS
intrusion detection systems
IEC
International Electrotechnical Commission
lESS
integrated electronic security systems
lETF
Internet Engineering Task Force
IF
intermediate frequency
IFC
intrafacility cabling
IG
isolated ground
ILEC
incumbent local exchange carrier
lMC
intermediate metal conduit
lOR
index of refraction
loT
internet of things
IP
ingress protection (e.g., IP52)
IP
internet protocol
IPD
integrated project delivery
IPsec
internet protocol security
IPTS
interactive patient TV system
TDMM, 14th edition
AA-16
© 2020 BICSJ®
Acronyms and Abbreviations
IR
infrared
lR
insulation resistance
ISDN
integrated services digital network
ISM
industrial, scientific, and medical
ISO
International Organization for Standardization
ISOC
Internet Society
ISP
inside plant
ISP
internet service provider
IT
information technology
ITB
invitation to bid
ITE
information technology equipment
ITS
information technology systems
ITU
International Telecommunications Union
IW
inside wire
=J
JCAHO
Joint Commission on Accreditation of Healthcare Organizations
JIS
Japanese Industrial Standard
.JPEG
Joint Photographic Experts Group
=K
KSU
key service unit
KTS
key telephone system
KVM
keyboard/video/mouse
© 2020 BICSI®
AA-17
TDMM, 14th edition
Acronyms and Abbreviations
=L
L2TP/IPSec
Layer 2 Tunneling Protocol/ internet protocol security
LAD
link access device
LC
latching connector
LCD
liquid crystal display
LCE
limited common element
LCX
leaky coaxial
LD
laser diode
LDP
local distribution point
LEC
line echo canceller
LEC
local exchange carrier
LED
light-emitting diode
LEED
Leadership in Energy and Environmental Design
LF
low frequency
LiDAR
light imaging detection and ranging
LLC
logical link control
LMDS
local multipoint distribution service
LMR
land mobile radio
LIVIS
land mobile service
locap
low-capacitance
LORAN
long range navigation
LoS
line of sight
LOTO
lock out- tag out
LP
low pressure
LPC
license plate capture
TDMM, 14th edition
AA-18
© 2020 BICSI®
Acronyms and Abbreviations
LPDA
log-periodic dipole array
LPR
license plate recognition
LSOH
low smoke zero halogen
LSA
Lotfrei Schraubfei Abisolierfrei
LSZH
low smoke zero halogen
LT
line terminal
LVD
low voltage disconnect
LW
long wavelength
LWAPP
lightweight access point protocol
=M
MAC
media access control
MAC
move, add, and change
MAHO
mobile assisted handoff
MAN
metropolitan area network
MAP
mobile application part
MC
main cross-connect
MC
metal clad
MCC
motor control center
MC-CDMA
multi-carrier code division multiple access
MCU
master control unit
MD
main distributor
MDA
main distribution area
MDI
medium dependent interface
MDP
main distribution panel
© 2020 BICSI®
AA-19
TDMM, 14th edition
Acronyms and Abbreviations
MDU
multi-dwelling unit
MDU-TR
multi-dwelling unit telecommunications room
MEGB
main electrical grounding busbar
mesh-BN
meshed bonding network
MF
medium frequency
MFD
mode field diameter
MGN
multiground neutral
MH
maintenance hole
MIB
management information base
MICE
Mechanical, Ingress, Climatic/Chemical, Electromagnetic
MIMO
multiple input multiple output
MIN
mobile identification number
M-JPEG
Motion-Joint Photographic Experts Group
MLT
multilevel transmission
MM
multimode
MMDS
multi-channel multipoint distribution service
MMDS
multipoint microwave distribution system
MMF
multimode fiber
MOV
metal oxide varistor
MP3
Moving Picture Experts Group layer 3
MPEG
Moving Picture Experts Group
MPO
multifiber push-on
MPOE
minimum point of entry
MPP
modular patch panel
MPTL
modular plug terminated link
TDMM, 14th edition
AA-20
© 2020 BICSI®
Acronyms and Abbreviations
MRE
makeready engineering
MRl
magnetic resonance imaging
MS
mobile station
MSC
mobile switching center
MSDS
material safety data sheet
MSS
meteorological-satellite service
MTBF
mean time between failure
MTTR
mean time to repair
MUTOA
multi-user telecommunications outlet assembly
=N
NA
numerical aperture
NAC
network admission control
NAC
notification appliance circuit
NAS
network attached storage
NC
network computer
NC
noise criterion
NCS
National CAD Standard
NEBS
Network Equipment-Building Systems
NE("l~
National Electrical Code@
NEMA
National Electrical Manufacturers Association
netid
network identification
NEXT
near-end crosstalk
NFPA
National Fire Protection Association
NI
network interface
© 2020 BICSI®
AA-21
TDMM, 14th edition
Acronyms and Abbreviations
NlC
network interface card
NiCd
nickel cadmium
NICU
neonatal intensive care unit
NIO
network interface device
NIST
National Institute of Standards and Technology
NMC
network management center
NOC
network operations center
NOS
network operating system
NPLFA
non-power-limited fire alarm
NPSBN
Nationwide Public Safety Broadband Network
NRC
noise reduction coefficient
NRTL
nationally recognized testing laboratory
NRZ
non-return-to-zero
NRZI
non-return-to-zero inverted
NT
network terminal
NTIA
National Telecommunications and Information Administration
NTSC
National Television System Committee
NVP
nominal velocity of propagation
NVR
network video recorder
NZS
New Zealand Standard
=0
0/E
optical-to-electronic
O&M
operations and maintenance
OBS
organization breakdown structure
TDMM, 14th edition
AA-22
© 2020 BICSI®
Acronyms and Abbreviations
oc
optical carrier
oc
outlet cable
OCPD
overcurrent protection devices
OD
outside diameter
ODBC
open database connectivity
OEM
original equipment manufacturer
OET
Office of Engineering and Technology
OFC
optical fiber conductive
OFCG
optical ftber conductive general purpose
OFCP
optical fiber conductive plenum
OFCR
optical fiber conductive riser
OFDM
orthogonal frequency division multiplexing
OFDMA
orthogonal frequency division multiple access
OFL
overfilled launch
OFN
optical fiber non-conductive
OFNG
optical fiber non-conductive general purpose
OFNP
optical fiber non-conductive plenum
OFNR
optical fiber non-conductive riser
OLED
organic light-emitting diode
OLT
optical line tet111inalltermination
OLTS
optical loss test set
OM
optical multimode
OMJ
optical rnultimode 1
OM2
optical multirnode 2
© 2020 BICSI®
AA-23
TDMM, 14th edition
Acronyms and Abbreviations
OM3
optical multimode 3
OM4
optical multimode 4
ONT
optical network terminal
ONU
optical network unit
OPM
optical power meter
OS
operating system
OS
optical singlemode
OSl
optical singlemode 1
OS2
optical singlemode 2
OSHA
Occupational Safety and Health Administration
OSI
Open Systems Interconnection
OSP
Office of Strategic Planning and Policy Analysis
OSP
outside plant
OSPF
Open Shortest Path First
OTDR
optical time domain reflectometer
=P
PA
average power
public address
PABX
private automatic branch exchange
PAD
packet assembler/disassembler
PAL
phase alternation line
PAM
pulse amplitude modulation
PAN
personal area network
PB
polybutylene
TDMM, 14th edition
AA-24
© 2020 BICSI®
Acronyms and Abbreviations
PB
pull box
PBB
primary bonding busbar
PBCC
packet binary convolutional coding
PBPP
pathway barrier penetration plates
PBX
private branch exchange
PC
physical contact
PCB
printed circuit board
PCM
pulse code modulation
PCS
personal communications system/service
PD
powered device
PDU
power distribution unit
PDU
protocol data unit
PE
polyethylene
PE
professional engineer
PERT
program evaluation review technique
PET
protected entrance terminal
PF
power factor
PFAS
personal fall arrest system
PFM
pulse frequency modulation
PHY
physical
PIC
plastic insulated conductor
PH>
passive infrared detector
PIN
personal identification number
PIN
positive intrinsic negative
© 2020 BICSI®
AA-25
TDMM, 14th edition
Acronyms and Abbreviations
PIR
passive infrared
PlY
personal identification verification
PL
performance level
PL
power-limited
PLC
programmable logic controller
PLFA
power-limited fire alarm
PM
phase modulation
PM
project management/manager
PMA
physical medium attachment
PMD
physical medium dependent
POCSAG
Post Office Code Standardization Advisory Group
PoE
power over Ethernet
POF
plastic optical fiber
PON
passive optical network
POP
point of presence
POS
point of sale
POT
portable operator's terminal
POTS
plain old telephone service
POU
power outlet unit
pp
peak power
PPE
personal protective equipment
PPM
pulse position modulation
PPTP
Point-to-Point Tunneling Protocol
PRCS
permit required confined space
TDMM, 14th edition
AA-26
© 2020 BICSI®
Acronyms and Abbreviations
PRJ
primary rate interface
PRR
pulse repetition rate
PSAACR-F
power sum attenuation-to-alien crosstalk ratio at far-end
PSAACR-N
power sum attenuation-to-alien crosstalk ratio at near-end
PSACR
power sum attenuation to crosstalk ratio
PSACRF
power sum attenuation-to-crosstalk ratio-far end
PSAFEXT
power sum alien far-end crosstalk
PSANEXT
power sum alien near-end crosstalk
PSE
power sourcing equipment
PSELFEXT
power sum equal level far-end crosstalk
PSIM
physical security information management
PSK
phase-shift keying
PSNEXT
power sum near-end crosstalk
PSTN
public switched telephone network
PTC
positive temperature coefficient
PTP
point-to-point
PTZ
pan, tilt, and zoom
PUC
public utilities commission
PUE
power usage effectiveness
PVC
permanent virhwl circuit
PVC
polyvinyl chloride
PWM
pulse width modulation
© 2020 BICSI®
AA-27
TDMM, 14th edition
Acronyms and Abbreviations
=Q
Q
quadrature signal
QAM
quadrature amplitude modulation
QC
quality control
QoS
quality of service
QPSK
quadrature phase-shift keying
=R
R/W
right-of-way
RACE
rescue, alarm, confine, extinguish
RADIUS
remote authentication dial-in user service
RADSL
rate-adaptive digital subscriber line
RAID
redundant array of independent disks
RARSR
radio alarm repeater station receiver
RAS
radio alarm system
RASSR
radio alarm supervising station receiver
RAT
radio alarm transmitter
RBB
rack bonding busbar
RBC
rack bonding conductor
REX
request to exit
RF
radio frequency
RFB
request for bid
RFI
radio frequency interference
RFI
request for information
RFI
request for interest
TDMM, 14th edition
AA-28
© 2020 BICSI®
Acronyms and Abbreviations
RFI
request for interpretation
RFID
radio frequency identification
RFoG
radio frequency over glass
RFI>
request for proposal
RFQ
request for qualifications
RFQ
request for quotation
RG
radio grade
RGB
rack grounding busbar
RGB
red, green, blue
RlJ
relative humidity
RJ
registered jack
RL
return loss
RMC
rigid metal conduit
rms
root mean square
RMU
rack mounting unit
RNC
rigid non-metallic conduit
RO
remote office
ROI
return on investment
RPE
radiation pattern envelope
RPP
remote power panel
RPR
resilient packet ring
RSTP
rapid spanning tree protocol
RTS
request to send
RU
rack unit
RZ
return to zero
© 2020 BICSI®
AA-29
TDMM, 14th edition
Acronyms and Abbreviations
=S
2G
second generation
S/E
signal to error
S/FTP
screened/foil twisted-pair
s
s1emen
Sa aS
software as a service
SAC
security and access control
SAN
storage area network
SAP
service access point
SAT
source address table
SAT
systems acceptance test
SBB
secondary bonding busbar
SBG
supplementary bonding grid
sc
subscriber connector
scs
structured cabling system
SCADA
supervisory control and data acquisition
sco
synchronous connection-oriented
SCSI
small computer system interface
ScTP
screened twisted-pair
scu
special care unit
SCUPC
subscriber connector-ultra physical contact
SD
schematic design
SDH
synchronous digital hierarchy
SDI
serial digital interface
TDMM, 14th edition
AA-30
© 2020 BICSI®
Acronyms and Abbreviations
SDK
software development kit
SDP
service discovery profile
SDR
software defined radio
SDR
standard dimension ratio
SDSL
symmetrical digital subscriber line
SEC AM
sequentiel couleur avec memoire
SF/UTP
overall braid and foil screened with unshielded twisted-pair
SFF
small form factor
SFP
small form factor pluggable
SHF
super high frequency
Sl
International System of Units
SIM
subscriber identity module
SLC
signaling line circuit
SM
singlemode
SMA
subminiature A
SMF
singlemode fiber
SMR
specialized mobile radio
SMS
short message service
SNI
standard network interface
SNMP
simple network management protocol
SNR
signal-to-noise ratio
SO NET
synchronous optical network
SoW
scope of work
SP
service provider
© 2020 BICSI®
AA-31
TDMM, 14th edition
Acronyms and Abbreviations
SPD
surge protection device
SPF
shortest path first
SPG
single-point ground
SPI
schedule performance index
SPL
sound pressure level
SPP
serial port profile
SRL
structural return loss
SS7
Signaling System No. 7
SSB
single sideband modulation
SSID
service set identifier
sso
single sign-on
ST
straight terminus
STDM
statistical time division multiplexing
STP
shielded twisted-pair
STS
shared tenant service
STS
static transfer switch
STS
synchronous transport signal
svc
switched virtual circuit
SWR
standing wave ratio
=T
3G
third generation
3GPP2
Third Generation Partnership Project Two
Tl
trunk level I
T3
trunk level 3
TDMM, 14th edition
AA-32
© 2020 BICSI®
Acronyms and Abbreviations
T&C
terms and conditions
TB
terminal block
TBB
telecommunications bonding backbone
TBBIBC
telecommunications bonding backbone interconnecting bonding conductor
TBC
telecommunications bonding conductor
TCP
transmission control protocol
TCP/IP
transmission control protocol/ internet protocol
TDD
telecommunications device for the deaf
TDD
time division duplex
TDM
time division multiplexing
TDR
technology distribution room
TDR
time domain reflectometer
TD-SCDMA
time division synchronous code division multiple access
TE
telecommunications enclosure
TEBC
telecommunications equipment bonding conductor
TEC
technology equipment center
TERM
terminal
TGB
telecommunications grounding busbar
TIA
'T'elecommunications Industry Association
TL
transmission level
TM
trade mark
TMGB
telecommunications main grounding busbar
TO
telecommunications outlet
TP
transition point
© 2020 BICSI®
AA-33
TDMM, 14th edition
Acronyms and Abbreviations
TP-PMD
twisted-pair physical medium dependent
TR
telecommunications room
TSB
Telecommunications Systems Bulletin
TTY
teletypewriter/text telephone
TVL
TV line
TX
transmitter
TXOP
transmit opportunity
=U
U/FTP
unshielded twisted-pair cable with foil screened twisted-pair conductors
U-NII
unlicensed national information infrastructure
U/UTP
unshielded twisted-pair cable with unshielded twisted-pair conductors
UBC
unit bonding conductor
uc
unified communications
UDP
user datagram protocol
UDS
uniform data system
UHF
ultrahigh frequency
UMTS
Universal Mobile Telecommunications Service
UPC
ultra physical contact
UPC
universal product code
UPS
uninterruptible power supply
USB
universal serial bus
USGBC
U.S. Green Building Council
usoc
universal service order code
TDMM, 14th edition
AA-34
© 2020 BICSI®
Acronyms and Abbreviations
UTC
undercarpet telecommunications cable
UTP
unshielded twisted-pair
uv
ultraviolet
=V
VAV
variable air volume
VCSEL
vertical cavity surface emitting laser
VDL
vertical down lead
VE
value engineering
VDSL
very high bit-rate digital subscriber line
VF
voice frequency
VFL
visual fault locator
VGA
video graphics array
VHF
very high frequency
VLA
vented lead-acid
VLAN
virtual LAN
VLF
very low frequency
VoiP
voice over internet protocol
VOM
volt-ohm-milliammeter
VPN
virtual private network
VRLA
valve-regulated lead-acid
vss
video surveillance system
VSWR
voltage standing wave ratio
© 2020 BICSI®
AA-35
TDMM, 14th edition
Acronyms and Abbreviations
=W
WA
work area
WAN
wide area network
WAP
wireless access point
WATS
wide area telephone service
WBS
work breakdown structure
WCDMA
wideband code division multiple access
WDM
wavelength division multiplexing/multiplexer
WEP
wired equivalent privacy
WG
working group
Wi-Fi
wireless fidelity
WLAN
wireless LAN
WMTS
wireless medical telemetry service
WPAN
wireless personal area network
ww
wireway
=X
xDSL
x digital subscriber line
XGA
extended graphics array
XLPE
cross-linked polyethylene
XML
extensible markup language
XPD
cross-polarization discrimination
=Z
ZD
zone distributor
ZDA
zone distribution area
TDMM, 14th edition
AA-36
© 2020 BICSI®
Acronyms and Abbreviations
Units of Measurement
oc
degree Celsius
OF
degree Fahrenheit
A
ampere
AH
ampere hour
amp
ampere
b
bit
b/s
bit per second
BTU
British thermal unit
cfm
cubic foot per minute
em
centimeter
dB
decibel
dB/km
decibel per kilometer
dB A
decibel A-weighting
dBm
decibel milliwatt
dBmV
decibel millivolt
dBu
decibel unloaded
dBV
decibel volt
dBW
decibel watt
EHz
exahertz
eV
electron volt
fc
foot-candle
© 2020 BICSI®
AA-37
TDMM, 14th edition
Acronyms and Abbreviations
fps
frames per second
ft
foot
ft2
square foot
ft3
cubic foot
Gb
gigabit
Gh/s
gigabit per second
GeV
giga-electron volt
GHz
gigahertz
H
henry
h
hour
HP
horsepower
Hz
hertz
in
inch
inWC
inch water column
in 2
square inch
K
Kelvin
kb
kilobit
kb/s
kilobit per second
kcmil
one thousand circular mils
KeV
Kilo-electron-vo It
kg
kilogram
kHz
kilohertz
km
kilometer
TDMM, 14th edition
AA-38
© 2020 BICSI®
Acronyms and Abbreviations
km/s
kilometer per second
kN
kilonewton
kPa
kilopascal
kV
kilovolt
kVA
kilovolt-ampere
kW
kilowatt
kWh
kilowatt hour
lb
pound
lbf
pound-force
m
meter
m2
square meter
mA
milliampere
Mb
megabit
Mb/s
megabit per second
MCM
one thousand circular mil
MeV
mega-electron volt
MHz
megahertz
MHz•km
megahertz• kilometer
mi
mile
mils
mile per second
mil
circular mil
Mm
megameter
mm
millimeter
© 2020 BICSI®
AA-39
TDMM, 14th edition
Acronyms and Abbreviations
mm2
square millimeter
ms
millisecond
mV
mill ivo It
mW
milliwatt
N
newton
mn
nanometer
ns
nanosecond
Pa
pascal
pF
picofarad
pF/m
picof~lrad
PHz
petahertz
ps
picoseconds
psi
pound per square inch
RU
rack unit
s
second
Tb/s
terabit per second
THz
terahertz
v
volt
V/m
volt per meter
VA
volt-ampere
Vac
volts alternating current
Vdc
volt direct current
Vpp
volts peak-to-peak
TDMM, 14th edition
per meter
AA-40
© 2020 BICSI®
Acronyms and Abbreviations
Vrms
volt root-mean-square
w
watt
YHz
Yottahertz
ZHz
Zettahertz
f!lli
micron
~as
microsecond
f!V
microvolt
© 2020 BICSI®
AA-41
TDMM, 14th edition
Acronyms and Abbreviations
bois
A
amplitude
c
capacitance
c
speed of light
f
frequency
G
conductance
I
current
L
inductance
N
refractivity
p
atmospheric pressure
p
power
R
resistance
T
temperature
t
time
z
impedance
£
permittivity
'A
wavelength
n
pi
q>
phase
TDMM, 14th edition
AA-42
© 2020 BICSI®
Chapter 1
Principles of
Transmission
Chaptet 1 focuses on the main concepts related to
signal transmission through metallic and optical fiber
transmission media, and current information related
to PoE.
Chapter 1: Principles of Transmission
Table of Contents
Metallic Media .....••...
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Electrical Conductors ....
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Description of Conductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Comparison of Solid Conductors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Solid Conductors versus Stranded Conductors . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Composite Conductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
American Wire Gauge (AWG) . . . . . . . . . . . • . • • . . . . . . . . . . . • • • • . . . 1-6
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Insulation . . • . . . . . . . . . . . • . • . . . . . . . . . . • • • . . . . .
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Electrical Characteristics of Insulation Materials . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Balanced Twisted-Pair Cables • . • . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Pair Twists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Tight Twisting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Environmental Considerations . . . • . . . . . . . . . . . • . . • . . . . . . . . . . . . 1-10
Electromagnetic Interference (EMI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Temperature Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Cable Shielding.
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Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Shielding Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Types of Shields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Solid Wall Metal Tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Conductive Non-metallic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Selecting a Cable Shield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Comparison of Cable Shields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Drain Wires
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Specifying Drain Wire Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
© 2020 BICSI®
1-i
TDMM, 14th edition
Chapter 1: Principles of Transmission
Analog Signals
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Sinusoidal Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Standard Frequency Bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
Decibel (dB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
Echo and Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22
Phase and Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22
Telephony
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
Telephone Line Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24
Telephony Echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24
Telephony Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25
Internet Protocol (IP) Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
Internet Protocol (IP) Telephony Devices . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
Internet Protocol (IP) Telephony Architecture . . . . . . . . . . . . . . . . . . . . . . . 1-26
Mission-Critical Data Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28
Digital Signals
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Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Transmission Data Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Converting an Analog Signal to a Digital Signal. . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Quantizing/Companding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-30
Pulse Code Modulation (PCM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-30
Time Division Multiplexing (TDM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
Converting Digital Data to Digital Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33
Encoding Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33
Quadrature Amplitude Modulation (QAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
Discrete Multitone (DMT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
8B/1Q4 PAMS Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
Digital versus Analog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-38
Types of Transmission Circuits ..••...........••..•..••..••.•• 1-39
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-39
Simplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-39
Half-Duplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-39
Full-Duplex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-39
TDMM, 14th edition
1-ii
© 2020 BICSI®
Chapter 1: Principles of Transmission
Asynchronous and Synchronous Transmission . . . . . . . . . . . . . . . . . . . 1-40
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-40
Asynchronous Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-40
Synchronous Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-40
Digital Hierarchy
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-41
Integrated Services Digital Network (ISDN) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-41
Digital Subscriber Line (DSL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-42
High Bit-Rate Digital Subscriber Line (HDSL) . . . . . . . . . . . . . . . . . . . . . . . . . . 1-42
Symmetrical Digital Subscriber Line (SDSL) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-42
Asymmetric Digital Subscriber Line (ADSL) Technologies . . . . . . . . . . . . . . . . . . 1-43
Rate-Adaptive Digital Subscriber Line (RADSL) . . . . . . . . . . . . . . . . . . . . . . . . . 1-44
Very High Bit-Rate Digital Subscriber Line (VDSL) . . . . . . . . . . . . . . . . . . . . . . . 1-44
Video Transmission
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Baseband Analog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
Composite Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
Component Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-47
Broadband Video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-47
Balanced Twisted-Pair Media Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . 1-47
Transmission line Concepts ••••.......•.•...........•..•••.. 1-48
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-48
Characteristic Impedance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53
Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-53
Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-54
Nominal Velocity of Propagation (NVP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-54
Propagation Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-54
Delay Skew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-55
Reflection Coefficient. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-55
Return Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-55
Signal-to-Noise Ratio (SNR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-56
Attenuation-to-Crosstalk Ratio (ACR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-56
Power Sum Attenuation-to-Crosstalk Ratio (PSACR) . . . . . . . . . . . . . . . . . . . . . 1-56
Power Sum Attenuation-to-Alien-Crosstalk Ratio at the Near End (PSAACRN) .... 1-56
Power Sum Attenuation-to-Alien-Crosstalk Ratio at the Far End (PSAACRF) ..... 1-56
Balanced Twisted-Pair Performance ...•..............••.•••.•. 1-57
© 2020 BICSI 0
1-iii
TDMM, 14th edition
Chapter 1: Principles of Transmission
Balanced Twisted-Pair Channel Performance .••••............... 1-58
Channel Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-58
Performance Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-59
Insertion Loss Performance Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-59
Near-End Crosstalk (NEXT) Loss Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-59
Power Sum Equal Level Far-End Crosstalk (PSELFEXT) Loss Limits . . . . . . . . . . . 1-59
Return Loss Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-60
Power Sum Attenuation-to-Crosstalk Ratio (PSACR) . . . . . . . . . . . . . . . . . . . . . 1-60
Concept of Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-60
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-61
Balanced Twisted-Pair Permanent link Performance ...•••.••..•• 1-62
Permanent Link Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-62
Balanced Twisted-Pair Patch Cords and Cross-Connect Jumpers . . . . . . . . . . . . . 1-62
Balanced Twisted-Pair Applications ........•.••............... 1-63
Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-63
100-0hm Balanced Twisted-Pair Performance Category . . . . . . . . . . . . . . . . . . . 1-64
Media Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-67
Distances and Pair Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-69
Shared Sheath Applications and Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . 1-72
Media Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-73
Impedance-Matching Devices (Baluns) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-73
Signal Converters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-73
Media Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-74
Transceivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 4
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-74
Power Over Ethernet (PoE). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 5
Power Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-75
Link Layer Discovery Protocol (LLDP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-76
Power Sourcing Equipment (PSE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-77
Optical Fiber
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-78
TDMM, 14th edition
1-iv
© 2020 BICSI®
Chapter 1: Principles of Transmission
Optical Fiber Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-79
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-79
Light-Source Characteristics that Influence Optical Fiber Selection . . . . . . . . . . . 1-79
Center Wavelength. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-79
Spectral Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-80
Average Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-81
Modulation Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-83
Transmitter Light Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-83
Light-Emitting Diode (LED) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-83
Short Wavelength Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-84
Vertical Cavity Surface Emitting Laser (VCSEL) . . . . . . . . . . . . . . . . . . . . . . 1-84
Laser Diodes ( LDs). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-86
Comparison of transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-87
Optical Fiber Receivers . . . . • • • . . . . . . . . . • . . . . . . . . . . . . . . . . . • . . 1-88
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
Characteristic Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
Sensitivity and Bit Error Rate (BER) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
Dynamic Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-88
Optical Fiber Medium
II
••
II
II
••
II
••
II
•
II
II
•
II
II
II
II
•
II
•
II
II
•
II
•
II
•
II
II
•
II
•
II
a
•
II
1-89
Optical Fiber Core Size Selection Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 1-89
Active Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-89
Transmission Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-90
Bandwidth . ....
1!11
•
Ill
••••••••••••
11
II
••••••••••••••••••••
II
•
"
••
1-91
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-91
Transmitters and Rise Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-92
Optical Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-94
Singlemode System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-94
Multimode System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-94
Chromatic and Modal Dispersion in Multimode Systems . . . . . . . . . . . . . . . . . . . 1-95
Chromatic Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-95
Modal Dispersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-95
Measurement and Specification of Multimode Systems . . . . . . . . . . . . . . . . . . . 1-95
Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-96
Classification of Optical Fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-98
Multimode Optical Fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-99
Wavelength Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l-101
Singlemode Optical Fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-102
© 2020 BICSI®
1-v
TDMM, 14th edition
Chapter 1: Principles of Transmission
Optical Fiber Applications Support Information .........••...... 1-103
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-103
Supportable Distances and Channel Attenuation . . . . . . . . . . . . . . . . . . . . . . . 1-103
Verifying Optical fiber Performance and Electronics Compatibility .. 1-105
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-105
Key Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-105
Verification Theory and Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-106
Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-107
Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-107
A. Calculating the Link Loss Budget . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-110
B. Calculating the Passive Cable System Attenuation . . . . . . . . . . . . . . . . . 1-112
Effects of Temperature on Optical Fiber Loss . . . . . . . . . . . . . . . . . . . . . . . 1-113
C. Verifying Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-113
Selecting an Optical Fiber Core Size to Application or Original
Equipment Manufacturer (OEM) Specifications . . . . . . . . . . . . . . . . . 1-116
Synchronous Optical Network (SONET) and Synchronous Digital
Hierarchy (SOH) Concepts .••.•••.••.••..••..•.......•••••• 1-116
System Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-118
Appendix ...............
II
•••••••••••••••
Ill
••••••••••••••••
1-121
North American Digital Signal (DS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-121
Digital Signal Level Zero (DSO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-121
Digital Signal Level One (DS1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-121
Digital Signal Level One C (DS1C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-122
Digital Signal Level Two (DS2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-122
Digital Signal Level Three (DS3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-122
Higher Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-123
European E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-124
B Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-124
E1 Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-124
E2 Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-124
E3 Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-124
Higher Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-125
TDMM, 14th edition
1-vi
© 2020 BICSI®
Chapter 1: Principles of Transmission
Figures
Figure 1.1
Calculated attenuation values for cables insulated with FEP, ECTFE,
and PVC from 1 MHz to 135 MHz at 22 °C (72 °F) . . . . . . . . . . . . . . . . 1-11
Figure 1.2
Calculated and measured attenuation values for cables insulated
with FEP, ECTFE, and PVC from 1 MHz to 135 MHz at 40 °C (104 °F)
1-12
Calculated and measured attenuation values for cables insulated
with FEP, ECTFE, and PVC from 1 MHz to 135 MHz at 60 °C (140 °F)
1-12
Figure 1.3
Figure 1.4
Example 1 of a sinusoidal signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Figure 1.5
Example 2 of a sinusoidal signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
Figure 1.6
IP telephony architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27
Figure 1.7
DS1 frame format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
Figure 1.8
E1 frame format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-32
Figure 1.9
Polar non-return-to-zero level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36
Figure 1.10
Bipolar AMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36
Figure 1.11
Biphase Manchester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36
Figure 1.12
Two binary bits encoded into one quaternary (281Q) . . . . . . . . . . . . . 1-36
Figure 1.13
MLT-3, also referred to as NRZI-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
Figure 1.14
Composite video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-46
Figure 1.15
Two-conductor transmission line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-48
Figure 1.16
Resistive model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-49
Figure 1.17
Capacitance model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-49
Figure 1.18
Inductive model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-50
Figure 1.19
Primary transmission line parameters . . . . . . . . . . . . . . . . . . . . . . . . 1-51
Figure 1.20
General transmission model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-52
Figure 1.21
Example of a channel test configuration . . . . . . . . . . . . . . . . . . . . . . . 1-58
Figure 1.22
Permanent link test configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-62
Figure 1.23
Typical configuration of endspan and midspan power source
equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-77
Figure 1.24
Spectral profile comparison of laser and LED . . . . . . . . . . . . . . . . . . . 1-80
Figure 1.25
Spectral width of an LED source showing full width half maximum .... 1-81
Figure 1.26
Numerical aperture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-82
Figure 1.27
System bandwidth versus distance example . . . . . . . . . . . . . . . . . . . . 1-91
Figure 1.28
Pulse distortion because of rise time and data rate . . . . . . . . . . . . . . . 1-93
Figure 1.29
Link bandwidth at 1300 nm using 62.5/125 micrometer multimode
optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-97
Figure 1.30
Core and coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-100
Figure 1.31
DSX optical multiplexing design . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-118
Figure 1.32
SONET multiplexing design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-119
Figure 1.33
WDM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-120
© 2020 BICSI®
1-vii
TDMM, 14th edition
Chapter 1: Principles of Transmission
Tables
Table 1.1
Conductor descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Table 1.2
Solid conductor properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Table 1.3
Electrical characteristics of common insulation types. . . . . . . . . . . . . . . 1-7
Table 1.4
Explanations of insulation electrical characteristics . . . . . . . . . . . . . . . . 1-8
Table 1.5
Types of cable shields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Table 1.6
Common units of frequency measurement . . . . . . . . . . . . . . . . . . . . . 1-18
Table 1. 7
Spectrums of standard frequency bands . . . . . . . . . . . . . . . . . . . . . . 1-20
Table 1.8
Power ratios from 0 to 60 dB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
Table 1.9
Transmission data rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29
Table 1.10
Coding methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-35
Table 1.11
ADSL standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-43
Table 1.12
ADSL performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-44
Table 1.13
VDSL data rate and target range . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-44
Table 1.14
Propagation delay/delay skew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-55
Table 1.15
Balanced twisted-pair cabling channel performance . . . . . . . . . . . . . . . 1-64
Table 1.16
Applications supported using 100-ohm balanced twisted-pair cabling .. 1-65
Table 1.17
Media selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-67
Table 1.18
Table 1.19
Transmission, speed, distance, and pair requirements . . . . . . . . . . . . . 1-69
Table 1.20
Characteristics of typical LED sources . . . . . . . . . . . . . . . . . . . . . . . . 1-83
Table 1.21
Characteristics of typical short wavelength laser . . . . . . . . . . . . . . . . . 1-84
Table 1.22
Characteristics of typical VCSELs . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-85
Table 1.23
Characteristics of typical LD sources . . . . . . . . . . . . . . . . . . . . . . . . . 1-86
Table 1.24
Comparison of transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-87
Table 1.25
Optical fiber cable performance by type. . . . . . . . . . . . . . . . . . . . . . . 1-90
Table 1.26
Summarized comparison of core sizes of multimode and
singlemode optical fiber cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-98
Table 1.27
Typical characteristics of multi mode optical fiber. . . . . . . . . . . . . . . . . 1-99
Table 1.28
Characteristics of 50/125 (Jm multimode optical fiber . . . . . . . . . . . . 1-100
Table 1.29
Characteristics of 62.5/125 !Jm multimode optical fiber . . . . . . . . . . . 1-101
Table 1.30
Typical characteristics of singlemode optical fiber . . . . . . . . . . . . . . . 1-102
Table 1.31
Maximum cable attenuation coefficient . . . . . . . . . . . . . . . . . . . . . . 1-104
Table 1.32
Mismatch of core size and power loss . . . . . . . . . . . . . . . . . . . . . . . 1-106
Table 1.33
Calculating optical fiber performance. . . . . . . . . . . . . . . . . . . . . . . . 1-108
Table 1.34
System gain, power penalties, and link loss budget calculations . . . . . 1-111
TDMM, 14th edition
IEEE 802.3 PoE classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-76
1-viii
© 2020 BICSI®
Chapter 1: Principles of Transmission
Table 1.35
Calculating losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-112
Table 1.36
Splice loss values in decibels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-113
Table 1.37
Minimum system loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-114
Table 1.38
Common SONET and SDH transmission rates . . . . . . . . . . . . . . . . . . 1-117
Table 1.39
Levels of multiplexing and carrier transmission in North America .... 1-123
Table 1.40
Levels of multiplexing and carrier transmission in Europe . . . . . . . . . 1-125
Examples
Example 1.1 Optical fiber performance calculations example . . . . . . . . . . . . . . . . 1-109
© 2020 BICSJ®
1-ix
TDMM, 14th edition
Chapter 1: Principles of Transmission
Metallic Media
IMPORI'ANT: It is assumed that the reader has an elementary knowledge of physics,
electronics, and electrical concepts.
Overview
Section 1 of this chapter provides basic information about how signals are transmitted
and received over metallic media. Section l also presents information specific to balanced
twisted-pair transmission topics, including:
• Transmission fundamentals.
• Standards.
• Applications support.
• Performance and equipment compatibility.
Section 2 of this chapter addresses optical fiber transmission topics, including:
• Transmission fundamentals.
• Standards.
• Applications support.
• Performance and equipment compatibility.
© 2020 BICSI®
1-1
TDMM, 14th edition
Chapter 1: Principles of Transmission
Electrical Conductors
Overview
An electrical conductor is any material that can carry an electric charge from one point to
another. The properties and cost of copper make it a suitable conductor for processing into
ICT wire and cable.
The most common electrical conductors for ICT wire and cable are:
• Copper.
• Copper-covered steel.
• High-strength copper alloys.
• Aluminum.
Silver and gold also are good electrical conductors, but they are not generally used because of
their high cost.
TDMM, 14th edition
1-2
© 2020 BICSI®
Chapter 1: Principles of Transmission
Description of Conductors
Table 1.1 gives a brief description of the most common conductors.
Table 1.1
Conductor descriptions
Conductor
Description
Copper
Sets the standard for comparing the conductivity of other
metals. Annealed copper is used as the reference value
(e.g., 100% conductivity). Other common conductors have
less than l 00% of annealed copper's electrical conductivity.
Copper-covered
Also known as copper-clad steel, it combines the
conductivity of copper with the strength of steel. It is
typically used as a conductor for aerial, self-supporting drop
wire. In the production of this type of conductor, a copper
layer is bonded to a steel core.
High-strength
A mixture of copper and other metals to improve certain
copper alloy properties and characteristics of copper. Alloys
such as cadmium-chromium copper and zirconium copper
offer important weight reductions or greater strength. These
factors are especially important in aerospace and computer
applications.
However, the alloying of pure copper always has an adverse
effect on its conductivity. The alloys mentioned above have
85% conductivity ratings.
Aluminum
© 2020 BICSI®
A bluish silver-white malleable ductile light trivalent metallic
element that has good electrical and thermal conductivity,
high reflectivity, and resistance to oxidation. It has about
60% conductivity compared with copper and is lighter in
weight than copper. Aluminum is most commonly used in
electrical utility distribution lines.
1-3
TDMM, 14th edition
Chapter 1: Principles of Transmission
Comparison of Solid Conductors
The properties of solid conductors made of ditTerent metals or alloys are shown in Table 1.2.
Table 1.2
Solid conductor properties
High-Strength
Alloys
Aluminum
I>roperty
Copper
Coppercovered
Electrical
conductivity
Sets the
standard
Less than
copper
85% typical
60% typical
Ductility
Good
Good
Best
Good
Solderability
Good
Good
Good
Special
techniques
Corrosion resistance
Good
Good
Poor
Good
Oxidation
resistance
Good
Good
Good
Poor
Weight
;:::::]4.25 kg
(31.4lb)
;:::::]3.06 kg
(28.8 lb)
·rensile
strength
250,000 kPa
(36,259 psi)
380,000 kPa
(55, 114 psi)
~4.32
kg
(9.5 lb)
To 550,000 kPa
(79,771 psi)
69,000 kPa
(I 0,008 psi)
NOTE: Weight and strength are approximate and based upon ~305 m ( 1001 ft) of l 0 AWG
solid conductor at 20 °C (68 °F).
Solid Conductors versus Stranded Conductors
Solid conductors consist of a single piece of metal wire. Stranded conductors bundle together
a number of small-gauge solid conductors to create a single, larger conductor.
Advantages of solid conductors include the following:
• Less costly
• Less complex termination systems
• Better transmission performance at high frequencies
• Less resistance
Advantages of stranded conductors include the following:
• More flexible
• Longer flex life
• Less susceptible to damage during crimp termination processes
TDMM, 14th edition
1-4
© 2020 BICSI®
Chapter 1: Principles of Transmission
Composite Conductor
Composite conductor is a term used to describe conductors constructed from nontraditional
materials (e.g., metallic resins, graphite). This conducting substance is impregnated into,
coated over, or between layers of polymer tape or other similar material. These types of
conductors are often used in telephone receiver and mounting cords, inexpensive headsets,
and other low-end audio devices. They also are used to embed audio devices into plastic
shells such as helmets.
Advantages of composite conductors include the following:
• Flexible
• Lightweight
• Inexpensive and easy to produce
• Easily embedded into other materials
• Low coeflieient of expansion
Disadvantages of composite conductors include the following:
• Poor analog transmission characteristics, including high attenuation, especially above
4000Hz
• Poor digital transmission characteristics
• Easily damaged unless encased in a rigid material
• Inconsistent quality
Cables with these types of conductors are not recommended for use with modern
telecommunications networks. If equipment is shipped with this type of cable, discard and
replace the cable with the proper structured cabling patch cord for the project.
© 2020 BICSI®
1-5
TDMM, 14th edition
Chapter 1: Principles of Transmission
American Wire Gauge {AWG)
Overview
Through usage and industrial standardization, the AWG sizing system has become generally
accepted in North America. The AWG system is important because it provides a standard
reference for comparing various conductor materials.
NOTE: For further information on AWG and conductor size, see Chapter 9: Power
Distribution.
Insulation
Overview
Insulation is used to isolate the flow of current by preventing direct contact between:
• Conductors.
• A conductor and its environment.
The insulation on most modern wire and cables consists of one or more plastic materials
applied by a variety of methods. Extruded polymers are generally used as insulation because
they have proven to be the most functional, dependable, and cost-effective insulation
materials.
The electrical performance of balanced twisted-pair cables is inversely related to the
insulation's dielectric constant and dissipation factor. Cables with a lower dielectric constant
and dissipation factor have better transmission performance, including lower attenuation
characteristics and lower capacitance.
Dielectrics also reduce the EM coupling between conductors by increasing conductor
separation.
Historically, telecommunications cable conductors were insulated with PVC and PE.
PVC-insulated conductors were commonly used for inside plant cables, and PE-insulated
conductors were commonly used for OSP cables. PE-insulated conductors display better
transmission performance. However, they are unsuitable for indoor use unless they are
encased in a suitable fire-retardant jacket material.
Certain materials provide lower smoke and flame spread characteristics as well as improved
transmission performance, including:
• FEP (e.g., Teflon';", NEOFLON FEPTM).
• ECTFE (e.g., Halarw).
NOTE: Teflon is a trademark of E. I. duPont de Nemours & Company, Inc.; NEOFLON FEP
is a trademark ofDaikinAmerica, Inc.; and Halar is a trademark of Solvay Solexis.
TDMM, 14th edition
1-6
© 2020 BICSI®
Chapter 1: Principles of Transmission
Electrical Characteristics of Insulation Materials
Table l.3 compares the electrical characteristics of various insulation types.
Table 1.3
Electrical characteristics of common insulation types
Insulation
Type
Dielectric
Constant
Dissipation
Factor
FEP
2.1
0.0005
PE
2.3
ECTFE
2.5
PVC (non-plenum rated)
3.4
PVC (plenum rated)
3.6
XL polyolefin
3.8
ECTFE =
FEP =
PE =
PVC=
XL=
0.01
0.04
Ethylene chlorotrifluoroethylene
Fluorinated ethylene propylene
Polyethylene
Polyvinyl chloride
Cross-linked
The electrical characteristics listed in Table 1.3 do not account for the increase in dielectric
properties that occur in all cables as temperatures rise. ECTFE and FEP insulations perform
better than PVC as temperatures increase. The dielectric properties of insulation materials can
have a significant effect on cable attenuation at high frequencies.
Table 1.4 explains the electrical characteristics used to compare and evaluate types of
insulation.
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Electrical Characteristics of Insulation Materials, continued
Table 1.4
Explanations of insulation electrical characteristics
Electrical
Characteristic
Dielectric constant
Explanation
The ratio of the capacitance of an insulated conductor to the
capacitance of the same conductor uninsulated in the air.
Air is the reference with a dielectric constant of 1.0.
Generally, a low dielectric constant is desirable. The
dielectric constant changes with temperature, frequency,
and other factors.
Dielectric strength
Measures the maximum voltage that an insulation can
withstand without breakdown.
Dielectric strength is recorded in breakdown tests in which
the voltage is increased at a controlled rate until the
insulation fails. The voltage at that time, divided by the
thickness of the insulation, equals the dielectric strength.
Dielectric strength is expressed in V per mm (or V per mil
where 1 mil equals 0.001 in).
A high value is preferred (to withstand voltage stress).
Insulated conductors in telecommunications applications
have a typical dielectric strength of between 7500 and
30,000 V per mm (300 and 1200 V per mil).
Dissipation factor
The relative power loss in the insulation is due to molecular
excitement and subsequent kinetic and thermal energy
losses.
This is of primary concern in the high-frequency MHz
ranges where signal loss increases because of the structure
of the insulating material. For example, polar molecules,
such as water, absorb energy in an electromagnetic field.
This effect is best understood in terms of microwave
heating. A low dissipation factor is preferable.
IR
The insulation's ability to resist the flow of current through
it. For inside conductors, IR is typically expressed in
megohm•km or megohm•! 000 ft.
NOTE: There is an inverse relationship between insulation
resistance and cable length (i.e., as the cable length
increases, the insulation resistance becomes
smaller).
IR = Insulation resistance
TDMM, 14th edition
© 2020 BICSI®
Chapter 1: Principles of Transmission
Balanced Twisted-Pair Cables
Overview
Metallic conductor cables commonly use balanced twisted-pair construction. Production of
small cables of this type involves twisting individual pairs and grouping those twisted pairs to
form either a cable or a unit for larger cable.
The main reason for twisting pairs of conductors is to minimize crosstalk and noise by
decreasing capacitance unbalance and mutual inductance coupling between pairs. Twisting
conductors also improves the balance (physical symmetry) between conductors of a pair and
reduces noise coupling from external noise sources.
Pair-to-pair capacitance unbalance is a measure of the electric field coupling between
two pairs if a differential voltage is applied on one pair and a differential noise voltage is
measured on another pair in close proximity.
Mutual inductance is a measure of the magnetic field coupling between two pairs if a
differential current is applied on one pair and a differential noise current is measured on
another pair in close proximity.
NOTE: The conditions under which crosstalk is measured include both capacitance
unbalance and mutual inductance coupling effects.
Pair Twists
Both mutual inductance and capacitance unbalance are affected by the relative length and
uniformity of pair twists. To minimize crosstalk within a multi pair cable, each pair is given a
different twist length within a standard range.
Generally, a counterclockwise twist length between ::::;SO mm and ::::;]50 mm ( 1.97 in and
6 in) is used for voice and low-frequency data cables. Adjacent pairs are generally designed
to have twist length differences of at least::::; 12.7 mm (0.50 in). These specifications vary
according to the manufacturer.
Tight Twisting
The option of tight twisting, where pair twist lengths are less than ::::;12.7 mm (0.50 in), is used
particularly within and between computers and other data processing equipment.
Category 5e, category 6, category 6A, and higher category cables employ tight twisting for
optimum transmission performance.
Tight twists tend to preserve their shape better in a cable. Longer twists tend to nest together
as they are packed in a cable, whereas shorter, tighter twists are less likely to deform.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Environmental Considerations
Electromagnetic Interference (EMI)
EMI is stray electrical energy radiated from electronic equipment and electronic systems
(including cables). EMI can cause distortion or interference to signals in other nearby cables
or systems.
NOTE: See Chapter 2: Electromagnetic Compatibility for a detailed discussion of EM I.
Temperature Effects
Balanced twisted-pair cables used in premises applications are expected to operate under a
variety of environmental conditions. One concern is the attenuation increase at higher cable
temperatures (above 20 °C [68 °F]).
High temperatures can be routinely encountered in:
• Exterior building walls.
• Ceiling spaces, including plenums.
• Installations using high levels of PoE.
• Mechanical rooms.
Intermittent failures have been reported in LANs as a result of solar heating of walls and
the cabling inside them. To avoid such problems, the attenuation at the highest expected
temperature must be used in the premises cabling design process.
Attenuation increases with temperature because of increased:
• Conductor resistance.
• Insulation dielectric constant.
• Dissipation factor.
The attenuation of some cables may exhibit significant variations because of temperature
dependence of the material.
All twisted-pair cables are referenced in the cabling standards at 20 °C +/- 3 °C
(68 op +!- 5.4 °F). For adjustment purposes, the attenuation increase is 0.2 percent per degree
Celsius for temperatures above 20 °C (68 °F) for screened cables, 0.4 percent per degree
Celsius for all frequencies and for all temperatures up to 40 °C (I 04 °F), and 0.6 percent per
degree Celsius for all frequencies and for all temperatures from 40 °C to 60 °C ( 104 °F to
140 °F) for all unscreened cables.
A temperature coefficient of 1.5 percent per degree Celsius is not uncommon for some
category 3 cables.
NOTE: Consult the manufacturer's specifications on the cable insertion loss margin
compared with the maximum insertion loss that is specified in the standard.
TDMM, 14th edition
1-10
© 2020 BICSI®
Chapter 1: Principles of Transmission
Temperature Effects, continued
Reference should be made to the relevant cabling component standard for the AHJ because
the attenuation requirements for each cable type and category or class vary.
Some insulation performs better than others under high temperature conditions. Figures l.l,
1.2, and 1.3 show a comparison of attenuation and frequency at various temperatures for:
• l 7 EP (e.g., Teflon@, NEOFLON'" FEP).
• ECTFE (e.g., Halar@).
• PVC.
For more information on Figures [.I, [ .2, and 1.3, refer to "Temperature-Related Changes in
Dielectric Constant and Dissipation Factor of Insulations Increase Attenuation in Data Cables
Used in Building Plenums," by C.Y.O. Lin and J.P. Curilla, which is available from IEEE@.
Figure 1.1
Calculated attenuation values for cables insulated with FEP, ECTFE, and PVC from 1 MHz to 135 MHz at
22 °C (72 °F)
210
200
,......,
co
------Measured attenuation results
obtained at 20 oc (68 °F)
150
lJ
"-'
c
0
:.::;
ro
::J
c
(j)
4-J
....,
100
~
50
0
1M
10M
30M
60M
135M
Frequency (Hz)
ECTFE = Ethylene chlorotrifluoroethylene
FEP = Fluorinated ethylene propylene
PVC= Polyvinyl chloride
© 2020 BICSI®
TDMM, 14th edition
Chapter 1: Principles of Transmission
Temperature Effects, continued
Figure 1.2
Calculated and measured attenuation values for cables insulated with FEP, ECTFE, and PVC from 1 MHz to
135 MHz at 40 oc (104 °F)
Measured attenuation
ii:i'
u
200
c
0
:;::;
150
(\J
::J
c
OJ
'-'
....,
<
100
50
0
1M
30M
10M
60M
135M
Frequency (Hz)
ECTFE = Ethylene chlorotrifluoroethylene
FEP = Fluorinated ethylene propylene
PVC= Polyvinyl chloride
Figure 1.3
Calculated and measured attenuation values for cables insulated with FEP, ECTFE, and PVC from 1 MHz to
135 MHz at 60 °C (140 °F)
- - - - - -Measured attenuation
c
0
:;::;
(\J
::J
c
ClJ
.j.J
~
1M
10M
30M
60M
135M
Frequency (Hz)
ECTFE = Ethylene chlorotrifluoroethylene
FEP == Fluorinated ethylene propylene
PVC= Polyvinyl chloride
TDMM, 14th edition
1-12
© 2020 BICSI®
Chapter 1: Principles of Transmission
Cable Shieldi
Description
A shield is a metallic covering or envelope enclosing the:
• Insulated conductor.
• Individual group of conductors within a core.
• Cable core.
Shields are made of foil, braided metal strands, or solid metal (often in a corrugated form
to allow cable bending). They arc usually tinned copper, bare copper, aluminum, or another
electrically conductive material.
When properly terminated, bonded, and grounded (earthed) cable shields can:
• Reduce the radiated signal from the cable.
• Reduce the effects of electrical hazards.
• Minimize the effect of external EMf on the conductors within the shielded cable.
Shielding Effectiveness
EM waves are attenuated and reflected by a shield. Consequently, the effectiveness of a shield
depends on such factors as the:
• Type and thickness of the shield material.
• Number and size of openings in the shield.
• Effectiveness of the bonding connection to ground.
The shielding effectiveness of a cable shield is determined by measuring the surface transfer
impedance. The surface transfer impedance is the ratio of the conductor-to-shield voltage per
unit length to the shield current. Surface transfer impedance is usually measured in milliohms
per meter or ohms per foot.
Cable shields are usually connected in such a way that they may be called upon to carry
relatively large ctments that are induced from an external field. The current flowing in the
shield results in a voltage drop along the shield because of the shield resistance. As a result,
there is a voltage gradient between the conductors inside the shielded cable and the shield
itself.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Types of Shields
There are many types of shields, including:
• Braided wire.
• Spiral-wrapped wire.
• Reverse spiral-wrapped wire.
• Metal foils, either helically or longitudinally wrapped.
• Hybrids, combining other types.
• Metal tubes.
• Conductive non-metallic materials.
Solid Wall Metal Tubes
A low-resistance solid wall metal tube (conduit) is the best possible shield, displaying
superior shielding properties at all frequencies. While solid metal tubes are used as shields in
some specialized applications, their rigid nature makes them inappropriate for most normal
cable applications.
Conductive Non-metallic Materials
Conductive non-metallic materials (e.g., semi-conductive tapes made with high carbon
content) are sometimes used at power and some low audio frequencies. These semiconductive shields are not normally used for applications at frequencies above 500 kHz.
Selecting a Cable Shield
Consider the following primary criteria when selecting a cable shield for a given application:
• Nature of the signal to be transmitted-Frequency range affects the performance of most
shields.
• Magnitude of the EM fields through which the cable will run-EM fields are usually
expressed in V/m at a given frequency.
• EMC regulations-Any cable operating within a given system must be designed to conform
to the EMC radiation limits of that system.
NOTE: See Chapter 2: Electromagnetic Compatibility.
• Physical environment and specific mechanical requirements-The shield may need to add
support to the cable.
NOTE: Overall cable size limitations also may affect this decision.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Comparison of Cable Shields
Types of cable shields are compared in Table 1.5.
Table 1.5
Types of cable shields
Single-Layer
Braid
Characteristic
Multiple-Layer
Braid
Foil
Foil+ Braid
Solid
Conduit
Flexible
Conduit
Shield
effectiveness
audio frequency
Good
Good
Fair to
excellent
NOTE: Depending
on the thickness of
foil and the shield
resistance of the
foil/foil + braid
Excellent
Good
Shield
effectiveness
radio frequency
Good
Excellent
Excellent
Excellent
Poor
Normal coverage
60-95%
95-97%
100%
100%
90-97%
Fatigue life
Good
Good
Fair
Poor
Fair
Tensile strength
Excellent
Excellent
Poor
Excellent
Fair
NOTE: In the shield effectiveness ratings:
• Poor means less than 20 dB.
• Fair means 20 to 40 dB.
• Good means 40 to 60 dB.
• Excellent means more than 60 dB.
The effectiveness of single-layer and multiple-layer braids against magnetic fields
is poor. For foil and conduit to effectively shield against magnetizable fields, a
high-permeability material must be used. Permeability is the property of a magnetic
substance that determines the degree in which it modifies the magnetic flux in the
region occupied by it in a magnetic field.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Drain Wires
Overview
lf a shield is not properly grounded, then its effectiveness is reduced. Drain wires are
sometimes applied in addition to a shield to provide an easier means for grounding (earthing)
the shield and to ensure shield continuity for metallic foil shields. A drain wire running the
length of the cable next to the shield provides ample grounding (earthing).
NOTE: Shield coverage over exposed conductors shall be maintained at a connector
termination and not only through a drain wire.
Drain wires are used:
• With foil, non-metallic, and hybrid shields.
• Occasionally with braided shields to make it easier to terminate the shield ground.
Applications
Drain wires are usually:
• Applied longitudinally next to the metallic part of the shield for the length of the cable.
• Made of solid or stranded copper conductors, which may be bare or tinned.
Specifying Drain Wire Type
The type of drain wire must be specified when selecting the type of cable. The termination
requirements of the application determine whether the drain wire should be made of bare or
tinned copper in stranded or solid construction.
TDMM, 14th edition
1-16
© 2020 BICSI®
Chapter 1: Principles of Transmission
Analog Signals
Overview
A review of some of the fundamental concepts of voice telephony is covered in this section.
It serves as an introduction to the subject of analog signals. Subsequent sections provide a
concise and in-depth treatment ofboth analog and digital transmission.
An analog signal is in the form of a wave that uses continuous variations in time (e.g., voltage
amplitude or frequency variations) to transmit information.
Sinusoidal Signals
The most fundamental example of an analog signal is a sinusoid. (see Figure 1.4).
Figure 1.4
Example 1 of a sinusoidal signal
A
....----------T---------·
0
360°
Time
A= Amplitude
0 =Zero
T = Time for one cycle
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Sinusoidal Signals, continued
A sinusoid is an oscillating, periodic signal that is completely described by three parameters:
• Amplitude
• Frequency
• Phase
In Figure 1.4, the amplitude of the sinusoid is A. The sinusoid oscillates with a period
indicated by the interval T, called the cycle time. The number of these periods that occurs in
a second defines the frequency (f) of the sinusoid in cycles per second (Hz). Cycle time and
frequency are related by the relationship f= 1/T. For example, a sinusoid with a cycle time of
.001 s has a frequency of I 000 Hz.
Hertz is the standard unit of frequency measurement. The range of frequencies that human
beings can hear is approximately 20 Hz to 20,000 Hz. Voice telephone circuits are generally
limited to the range of 300 to 3400 Hz, which provides adequate quality for normal
conversation.
Standard notations for frequencies often encountered in communications systems are shown
in Table 1.6.
Table 1.6
Common units of frequency measurement
Unit
Value
kHz
1000Hz
MHz
1,000,000 Hz (1000kHz)
GHz
I ,000,000,000 Hz (I 000 MHz)
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Sinusoidal Signals, continued
Phase is a description of the reference time, t = 0. For example, the sinusoid shown in
Figure 1.5 has the same amplitude and frequency as the sinusoid in Figure 1.4; these two
sinusoids differ only in phase (by 90 degrees in this case). One cycle is equal to 360 degrees.
Figure 1.5
Example 2 of a sinusoidal signal
A
0
Time
A= Amplitude
0 =Zero
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Sinusoidal Signals, continued
Mathematically, any sinusoid can be expressed as:
v(t) =A sin (2n:ft + <p)
Where:
A
=
Amplitude
f
Frequency
<p
Phase
Time
Sinusoidal signals are of fundamental importance in understanding signal transmission. This
is largely the result of a mathematical theory developed by Joseph Fourier ( 1768-1830).
Fourier was able to show that any analog signal can be mathematically described as a sum of
sinusoidal signals that differ in amplitude, frequency, and phase. This description of a signal
in terms of its sinusoidal components is called the signal's spectrum.
A consequence of Fourier's theorem is that the transmission of an analog signal can be
viewed as the transmission of its individual sinusoidal components. ft follows that if the
received signal is to be an exact duplicate of the transmitted signal, then the transmission
system must not change the frequency of any components. Furthermore, the relative
amplitudes and phases of all components must be maintained. The frequency range of the
sinusoidal signals needed to describe an analog signal defines the signal's bandwidth.
Standard frequency Bands
The bandwidths, which are also called spectrums, of several standard frequency bands are
shown in Table 1.7.
Table 1.7
Spectrums of standard frequency bands
Band
Symbol
Description
Range
Audio
VLF
Very low frequency
3-30kHz
Audio
LF
Low frequency
30-300 kHz
Radio (RF)
MF
Medium frequency
300--3000 kHz
Radio (RF)
HF
High frequency
3-30 MHz
Video (TV) and Radio (RF)
VHF
Very high frequency
30-300 MHz
Video (TV) and Radio (RF)
UHF
Ultra high frequency
300-3000 MHz
Video (TV)
CATV
Community antenna TV
54-1002 MHz
Radar
SHF
Super high frequency
3-30 GHz
Radar
EiiF
Extremely high frequency
30--300 GHz
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Decibel (dB)
An important property of a signal is its strength (power), which is often expressed in decibels.
The decibel is a measure that compares two power levels. The decibel is defined as:
It is critical to observe that the dB is a relative power measurement. The power of a signal
(PI) stated in decibels indicates the power of that signal relative to some reference power (P,).
Table 1.8 shows a range of 0 to 60 dB and the power ratios that they express.
Table 1.8
Power ratios from 0 to 60 dB
Decibels
Power Ratio
Decibels
Power Ratio
0
1.0
16
39.8
1
1.3
17
50.1
2
1.6
18
63.1
3
2.0
19
79.4
4
2.5
20
100.0
5
3.2
30
1000
6
4.0
40
10,000
7
5.0
50
100,000
8
6.3
60
1,000,000
9
7.9
10
10.0
II
12.6
12
15.8
13
20.0
14
25.1
15
31.6
Table 1.8 indicates that if PI has 100 times the power ofP 2, then PI has a power of 20 dB
relative toP. A doubling of power also results in a change of +3 dB. Ifthe power in a signal is
reduced by one-half, then the power change is -3 dB. (This observation follows from the fact
that log (x) =-log ( 1/x), which implies that log(x) is negative for all x< 1.)
It is often convenient to define a signal power to be used as a reference. For instance, I m W is
frequently used as a reference power in telephony. The power of a 50.1 m W signal would be
expressed as 17 dBm. Notice that m is added to dB to indicate that the reference power is
1 m W. If a reference power of I W is used, the signal power is expressed as dB W.
Decibel levels are used to express power ratios of all types of analog and digital signals,
regardless of the medium.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Echo and Delay
Another phenomenon that occurs in signal transmission is echo. When a signal encounters a
discontinuity in the impedance of the medium carrying the signal, some of the signal power is
reflected back to the transmitter. The reflected signal appears as a delayed version (e.g., echo)
of the original signal. A familiar, but extreme, example of this phenomenon is when a sound
wave encounters a rock wall.
Echoes of voice are occurring at all times, but they usually return so fast that they cannot be
distinguished from the original sound. For an echo to be experienced, there must be enough
delay for it to be distinguishable from the original source of the sound. In telephony, delays
greater than 50 ms are perceptible if they are of sufficient strength.
Phase and Delay
As previously mentioned, one of the three defining parameters of a sinusoidal signal is phase.
The two sinusoids shown in Figures 1.4 and 1.5 differ only in phase. Note that the signal in
Figure 1.4 is simply a delayed (in time) version ofthe signal in Figure 1.5. Thus, the delay of
a sinusoidal signal can be equally well expressed as either a phase shift or a time delay.
It should be observed that the result of adding the two sinusoids of the same frequency would
depend on their phase difference. For example, if the phase difference is zero, then the sum
will be a single sinusoid with amplitude 2A. However, if the phase difference is exactly onehalf of the period, then the sum will be zero. Two sinusoids whose sum is zero are considered
180 degrees "out of phase."
For more complex signals that are composed of many sinusoidal components, a delay is
expressed only in time (seconds), not in phase.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Telephony
Overview
A telecommunications transmission system consists of three basic components:
• Source of energy
• Medium to carry the energy
• Receiving device
In telephony, the three basic components of the transmission system are:
• Source of energy-The acoustic energy of speech is convet1ed to an equivalent electrical
signal at the transmitting handset by a microphone.
• Medium to carry the energy-A balanced twisted-pair cable is commonly used as the
transmission medium.
• Receiving device-The transducer in the receiving handset acts like a small loudspeaker
and converts the electrical energy back to sound energy for the ear.
Analog telephones convert voice information (sound waves) into electrical analog signals that
can be transmitted over longer distances than the sound waves can travel.
Although speech may contain frequencies from 50 Hz to 12 kHz, early studies found that
good quality speech intelligibility could be obtained if only the frequency range of about
300 Hz to 3400 Hz was actually transmitted. Consequently, this is the frequency band that
early telephone circuits were designed to support.
The electrical signal corresponding to the voice waves is transmitted over a pair of conductors
with some loss of energy, but under proper conditions, without substantial distortion. To work
as a circuit, two conductors arc required to carry the electrical signal. Current sent on one
conductor must eventually return to the source. In the early days of telecommunications, earth
was used as one of the conductors. This was found to be noisy, and eventually two conductors
were used. This marked the beginning of the telecommunications cabling industry.
Devices that convert electrical energy back into sound energy arc typically called receivers.
The receiver is an EM device, much like a miniature loudspeaker that converts the electrical
waveform back into an acceptable reproduction of the original sound.
The handset is the part of the telephone that is held close to the mouth and ear. The
transmitter and receiver are mounted in the handset. A typical analog telephone includes a
handset and a dialing mechanism.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Telephone line Impedance
The telephone from which the voice signal originates can be considered a signal generator
that is connected to a load, which is a combination of the connecting cables and the other
telephone. The connecting cables make up a transmission line.
The maximum transmission of electrical power occurs when a transmitting device and a
receiving device have the same load resistance or, more specifically, the same impedance.
Impedance is a parameter that applies to ac signals. Like resistance, impedance is expressed
in ohms, but it has both a magnitude and a phase component.
It is important to ensure that the source or load impedance connected to a line is matched
in the best way possible for maximum efficiency. Telephone cables have a characteristic
impedance that depends on frequency. ln voice-band applications, a typical impedance of
either 600 or 900 ohms is used to match the cable pairs. The 600 ohms impedance is preferred
for private line circuits and trunks while 900 ohms is used in CO switching system line
circuits.
NOTE: The characteristic impedance of telephone cable pairs is approximately 600 ohms for
22 A WG cables and 900 ohms for 26 A WG cables.
Telephony Echo
Occasionally, users might encounter echoes on long-distance calls. For an echo to be
perceived, part of the transmitted signal must be sent or reflected back to the originating end.
Part of a transmitted signal is sent back to the transmitter (reflected) when the impedances of
the transmission line and the receiver are not matched. In this case, the maximum power is
not transmitted. Matching these impedances improves transmission efficiency and minimizes
the echo.
Many of us have been given the impression that electricity always travels at the speed oflight
(;:::300,000 km/s [186,000 mils]). Since light is an EM wave, this speed applies to all EM
radiation in free space. The speed of light in free space is usually represented by the
symbol c. EM radiation travels slower than c in any physical medium. For example, signals
travel slower in cables-about .56 c to 74 c. Longer circuits will have proportionately longer
delays. The signal propagation speed in twisted-pairs will depend on the type of insulation
used and its thickness, among other factors.
Although satellite signals travel at velocity c, geostationary satellites are such a great distance
away (;:::35,786 km [22,236 mi]) that the round-trip delay is close to l/4 sand is quite
perceptible when holding a telephone conversation.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Telephony Distortion
The transmission characteristics of conductor pairs vary with frequency. Consequently,
the various sinusoidal frequency components of a signal that are sent over a transmission
line will emerge in a somewhat different form--each signal component will experience a
signal loss and a phase shift that is frequency dependent. At voice frequencies, the principal
elements contributing to loss and phase distortion are the conductor resistance and the mutual
capacitance of the cable pair.
Increasing the frequency increases the speed of transmission through cable pairs. Using the
example of 19 AWG balanced twisted-pair cable, the velocity of transmission is :::::37,000 km/s
(23,000 mils) at 300 liz. At 3400Hz, the velocity of transmission is :::::125,529 km/s
(78,000 mils). This frequency-dependent transmission speed variation does not noticeably
affect speech intelligibility, but it can have a great effect on data transmission.
The application of inductors, called loading coils, placed at intervals along a cable improves
speech transmission quality. Loading coils:
• Compensate for the capacitance of a cable pair.
• Reduce the capacitive current loading in the range of audio frequencies.
The most common distances between loading points are :::::1.37 km ( 4495 ft) for 0 loading and
:::::].83 km (6004 ft) for H loading.
NOTE: Load coils, by their design, will cut off frequencies above the voice range. Because of
this, load coils will block analog high fidelity and digital signals.
Although loading coils improve speech, they adversely affect data transmission. While
loading improves the loss versus frequency characteristics, it causes severe delay problems.
The delay of the higher frequencies is far greater on loaded facilities than non-loaded
t~1cilities. Loading coils also limit the frequency at which information can be transmitted.
The loading coil spacing determines the upper cutoff frequency. The shorter the spacing is
between loading points, the higher the cutoff frequency.
© 2020 BICSI®
1-25
TDMM, 14th edition
Chapter 1: Principles of Transmission
Internet Protocol (IP) Telephony
Traditional voice systems utilize a local premises telephone switch or CENTREX lines.
Calls are then routed through the PSTN. IP telephony systems use the packet-switched data
networks for voice communications. Internal calls are established through Ethernet switches
using lP to the desktop. A processor or server controls call traffic.
External calls can be routed over an existing data network to the Intemet or over the public
telephone network. Data networks must have QoS capabilities to support IP telephony.
Although speech does not usc much bandwidth, it cannot tolerate delays or traffic bottlenecks.
Internet Protocol (IP) Telephony Devices
Three common interface options are available for use with IP telephony:
• An IP telephone-looks like a telephone but has features of a computer
• A computer with IP telephony software and a microphone/speaker or USB handset
• Multifunctional devices with a wireless receiver (e.g., handheld wireless device, media
devices, other mobile media device)
IP telephones allow access to more advanced services (e.g., online voice mail, call
forwarding, cloud services). They also can be used as switches to connect a computer directly
to the telephone.
A computer with IP telephony software is limited to the reliability and capabilities of the
computer and is only operational when the computer is running.
Multifunction handheld mobile devices allow for the downloading of music, videos, and other
files from the Internet using wireless technology.
Internet Protocol (IP) Telephony Architecture
There are three common implementation options for lP telephony architecture (see
Figure 1.6):
• Separate lines-one for the IP telephone and one for the computer
• One line for everything using a dual-port lP telephone or softphone
• Wireless connection using APs to connect the IP telephone
Deciding to install a dual-port IP telephone or softphone, using one line for everything,
may seem an attractive option since it requires just one data cable for two devices-the IP
telephone and computer. However attractive that option sounds at first, a single cable carrying
all information reduces flexibility and redundancy. For example, the need for additional
or upgraded services (e.g., lOOOBASE-T) may require pulling new cables, which means
disrupting services and additional costs.
Two telecommunications outlets or connectors are recommended for each individual work
area-one may be associated with voice and the other with data. Since IP telephony is now
being added to the data network, both horizontal cables at the work area location should be
considered cables that support data applications.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Internet Protocol (IP) Telephony, continued
NOTE: Throughput to the computer may be limited by the telephone throughput when one
cable is provided.
Figure 1.6
IP telephony architecture
WA
Network switch
[ll_J::i________ _
lllliiBIIIIIIIIIIBIIIIII
Ill
1i11 Ill
a M Ill Ill II Ill a
Separate line for IP telephone and computer
WA
Q
Network switch
1!11
B
II
Ill
II
illl:
Ill
Ill
II
II
B
Ill
B
a
B
a
B
Ill
Ill
Ill
Dual port IP telephone
ci-
WA with
IP telephone software
Network switch
•
Ill
Ill
Ill
•
Ill
B
II
B
II
••••
Ill
Ill
II
Ill
Ill
•
----
CiTI ' ' ' ' ''I WI
Telephone
Network switch
~- ~
a
~~Ir~-iiir~pr--- EJ /VVV lill
~D
WA
IP = Internet protocol
NIC = Network interface card
WA = Work area
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Internet Protocol (IP) Telephony, continued
Mission-Critical Data Network
IP telephony makes it critical to ensure an uninterrupted transmission and high QoS on the
data network. Structured cabling systems must be carefully controlled to ensure a minimum
performance equivalent to category 5e/class 0 cabling, preferably at category 6/class E or
higher for optimum IP telephony performance. As a critical need for any telephone system
is the ability to function at any time, especially during a power outage, uninterrupted power
in IP telephony is provided by using PoE. The implementation of structured cabling for IP
telephony also must consider both present and future application requirements.
NOTE: Where JP telephone communications is vital for life safety or emergency
communications, PoE power sources should have emergency power or a UPS.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Digital Signals
Definition
A digital signal changes from one state to another in discrete steps. Figures 1. 7 through 1.11
show examples of digital signals. The most significant property of digital signals is that
at any time they can take on only a value from a discrete set of values. For example, the
digital signal in Figure 1.12 can have only one of four possible values. Analog signals can be
converted to digital data using a process called AID conversion, as explained below.
Transmission Data Rates
Typical rates encountered in the transmission of digital data are shown in Table 1.9.
Table 1.9
Transmission data rates
Transmission Rate Unit
Definition
b/s
1 b/s
kb/s
1000 b/s
Mb/s
1,000,000 b/s
Gb/s
1,000,000,000 b/s
Tb/s
1,000,000,000,000 b/s
Converting an Analog Signal to a Digital Signal
Analog signals (e.g., speech, video) can be converted into a digital signal by a multistep
process:
l. Filtering
2. Sampling
3. Quantizing/companding
filtering
Since the sampling rate is determined by the analog signal's frequency content, the analog
signal is filtered before being sampled to limit its frequency content.
Sampling
Sampling involves observing the exact value ofthe analog signal at regular time intervals.
The sampling rate must be at least twice the highest frequency component of the analog
signal to faithfully reproduce the analog signal when it is converted from analog to digital
data and then back to analog.
For example, a sampling rate of8000 samples/sis required to digitize a speech signal
containing frequencies up to 4kHz. For high-fidelity speech or music signals containing
frequency components up to 16 kHz, the sampling rate needs to be increased to
32,000 samples/s.
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Converting an Analog Signal to a Digital Signal, continued
Quantizing/ Companding
'T'he final step in the process involves quantizing the sampled values. Each sampled value is
assigned a discrete level, which approximates the analog signal at the sampling instant. For
example, if the source signal varies in amplitude between 0 and 1 V, each sample value could
be assigned one of 256 discrete levels within this range. The increments between levels can
be uniform or follow a non-uniform relationship.
In the case of speech signals, it is desirable to assign a greater number of levels when the
speech signal is weak (close to zero) than when the speech signal is strong (close to one).
This non-uniform mapping between the analog sampled value to an assigned digital level is
called companding. It is used to increase the SNR of low-level signals, which improves the
intelligibility of speech as perceived by the human ear.
There are two types of companding in current use called A-Law and Mu-Law. Mu-Law is
used in the United States, Canada, and Japan. A-Law is used in Europe. Although performing
similar functions, the algorithms used are different, and the two are not compatible.
The tlnal result of these three operations is to convert an analog signal to an equivalent
sequence of digital data. The entire process is called PCM.
Pulse Code Modulation (PCM)
As an illustration of PCM, each sampled value of an analog signal is assigned one of
256 levels, which can be represented by an 8-bit binary number. For example, a sample value
of 137 can be represented as the binary number I 000 I 00 I. It follows that an analog speech
signal with a 4 kHz bandwidth can be represented by a binary data sequence having a bit
rate of:
8000 samples/s x 8 bits/sample= 64,000 b/s, assuming 8-bit quantization for
each sampled value
Digital signal processing is used to encode speech signals at data rates lower than 64 kb/s.
ADPCM can use 40, 32, 24, or 16 kb/s. PCM and ADPCM attempt to reproduce the input
speech signal waveform as accurately as possible. Devices called codecs do the conversion of
speech to digital data and its subsequent decoding to speech.
Other, more complex, techniques process the speech signal in frames (e.g., 20 ms in length)
and extract basic descriptive parameters from each frame. These techniques use devices
called vocoders (rather than codecs). Using vocoders, speech can be transmitted at rates from
8 to 2.4 kb/s.
Lower bit rates typically imply a degraded signal quality.
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Chapter 1: Principles of Transmission
Time Division Multiplexing (TDM)
Telecommunications systems typically combine binary data from several different sources
(e.g., voice channels) into a single composite bit stream. This process is called TOM. TOM
is one means of increasing the information-carrying capacity of a digital telecommunications
channel. TOM is accomplished by predetermined (deterministic) interleaving of samples
from different voice channels along with one or more bits for control purposes to make up a
frame. The most popular form of TOM is a statistical TOM that allows more effective, nondeterministic interleaving.
Most TDMs assign time slots to data by user addresses or codes. If the data fills the user's
assigned time slots, then the remaining data must wait for the same slots in the next rotation.
lfthe user does not have data, then the slot remains empty until the user transmits again. Both
ofthese cases are inefficient.
Statistical TOM corrects this problem by statistically sampling and segmenting the data into
multiple frames. These frames are then loaded into available empty time slots as they appear.
This process greatly improves the multiplexer's efficiency, but it does not deal with the issue
of partial time slot usage.
Two classic examples of TOM are the OS 1 format and CEPT PCM-30 format. These are both
subject to ITU-T Recommendation 0.704.
In the OS 1 format, the digital data from 24 speech channels is combined for transmission
over a single transmission channel. The data from the 24 voice channels is arranged in a
frame, as shown in Figure l .7.
Figure 1.7
DSl frame format
/ F r a m i n g bit
lb
Sb
Sb
8 b
8 b
b =Bit
Ch =Channel
For telephone quality, speech is sampled at a rate of 8000 samples/s. Thus, an 8-bit speech
sample is generated every 1/8000 = 125 !JS for each speech channel. Consequently,
transmission of the digital speech data requires sending one 8-bit sample every 125 !JS for
each channel, as shown in Figure 1. 7. One bit is added to each frame for control purposes.
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Chapter 1: Principles of Transmission
Time Division Multiplexing (TOM), continued
The data rate for this format is:
(8 b/s channel x 24 channels+ l framing bit) x 8000 frames/s
=
1.544 Mb/s
Tl lines are designed to carry DS I frames.
The classic European example ofTDM is the CEPT PCM-30 format. In the CEPT PCM-30
format, the digital data from 30 speech channels is combined for transmission over a single
transmission channel.
The data from the 30 voice channels is arranged in a frame together with alignment, alarms,
and signaling, as shown in Figure 1.8.
Figure 1.8
El frame format
8b
8b
8b
8b
8b
8b
8b
8b
8b
TSO
Slot 0
Alarms,
etc.
TSl
Channel
l
TS2
Channel
2
TS15
Channel
15
TS16
Signaling
TS17
Channel
16
TS18
Channel
17
TS30
Channel
TS31
Channel
30
29
b = Bit
TS = Timeslot
For telephone quality, speech is sampled at a rate of 8000 samples/s. An 8-bit speech sample
is generated every 1/8000 = 125~ts for each speech channel. Consequently, transmission of
the digital speech data requires sending one 8-bit sample every 125~ts for each channel, as
shown in Figure 1.8. Eight bits are added to each frame for service purposes and 8 bits for
signaling.
The data rate for this format is:
(8 b/s channel x 32 channels) x 8000 frames/s
=
2.048 Mb/s
TOM also is used to multiplex signals from a lower level in the digital hierarchy to a higherlevel signal. For example, four Tl (OS I) signals can be combined to form a T2 (DS2), or 28
T I can be combined to form a T3 (DS3) signal. In Europe, four E I signals can be combined
to form an E2 (8 Mb/s), four E2 can be combined to form an E3 (34 Mb/s), or four E3 can be
combined to form an E4 (140 Mb/s) signal.
The process of reconstituting the individual channels from the composite signal is called
demultiplexing. The multiplexing and demultiplexing equipment is commonly called a
channel bank. Modern units also are called intelligent multiplex terminals.
ft is important to remember that only the first order multiplexing stage (Tl or El) contains
any AID conversion. From the second order upward, the system only deals with digital
frames. It is not possible to extract a single channel fl·om the digital stream without
demultiplexing back to the first order stage.
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Chapter 1: Principles of Transmission
Converting Digital Data to Digital Signals
In both the T and E formats, frames are combined into multiframes. In the United States,
multiframes are often referred to as superframes ( 12 T1 t1·ames = 1 superframe) or extended
superframes (24 T2 frames = 1 ESF)-in Europe 16 E I frames I multi frame.
Digital signals are used to encode digital data (e.g., sequences of ones and zeros). Each one or
zero is called a bit (i.e., short for binary digit). The bit is the basic unit of digital data.
Digital data is represented (encoded) using digital signals that represent (encode) the
original sequence of data bits. There are many ways to do the encoding; Figures 1. 9 through
1.13 show some ofthe common options. Having several encoding options allows an ICT
distribution designer to select a digital signal that best matches the telecommunications
channel being used.
Encoding Techniques
A sequence of binary pulses consisting of ones and zeros is not the optimum format for
transmitting digital data over balanced twisted-pair cables. The final step in the encoding
process is the modification of the shape and pattern of pulses to achieve more efficient
transmission.
Various techniques are used to shape the pulses to limit the bandwidth (frequency content) of
the transmitted signal. This improves the signal relative to the noise induced from adjacent
systems that are operating in the same cable.
Line-encoding techniques are designed to:
• Eliminate the de component, which can have an adverse effect on signal detection.
• Improve timing recovery.
Two common methods of encoding are:
• Inverting alternate pulses fix ones and using a zero level for zeros. Many consecutive zeros
are replaced with a unique pattern (B8ZS). This technique is used for T1 carriers and is
commonly referred to as bipolar alternate mark inversion (AMI [see Figure 1.1 OJ).
• Using Manchester (or differential Manchester) coding where each bit within a unit data bit
interval is represented by a positive pulse over one half the interval and a negative pulse
over the remaining half interval. Thus, a signal transition occurs in the middle of every
bit interval. These regularly occurring signal transitions provide time information for the
receiver (see Figure 1.11 ).
As previously discussed, a digital signal can assume one of a finite number of states
(e.g., signal levels) in each encoding interval. The digital signal is typically restricted to
change states only at regularly spaced time intervals. For example, in Figure 1.9, the number
of possible levels is two, and each time interval (designated as T in the figure) encodes a
single bit.
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Converting Digital Data to Digital Signals, continued
Figure 1.12 shows a digital signal that has four possible states (levels) that can be selected in
each encoding interval. Each possible level can be associated with a different two-bit pattern.
ln this figure, the rate of state change is one-half the data rate. 1fa digital signal was allowed
to choose between eight states in each encoding interval, three bits per encoding interval
could be encoded and transmitted.
In Figure 1.11 the bits are encoded by changes in signal level. In the middle of each encoding
interval, if the transition is positive, a one is encoded; if the transition is negative, then a
zero is encoded. These transitions occur at a regular rate and determine the bit rate. The rate
at which signal level changes occur may be twice the bit rate (e.g., consider the Manchester
digital signal that encodes a continuous string of ones or zeros).
NOTE: The rate at which the digital signal state changes and the bit transmission rate are not
necessarily the same.
The term baud is often encountered when discussing modems. It describes the rate at which
a signal can change state. One baud is equal to one state change per second. As noted above,
the rate at which a digital signal can change state may or may not be the rate that the signal
transmits binary data (b/s). For example, in Figure 1.9, the signaling rate in bits per second
and the signaling rate in baud are the same; however, in Figure 1.11, the signaling rate in bits
per second is half the signaling rate in baud.
With the proper encoding method, higher data speeds are achieved by using encoded symbols
at lower line rates. This increases the distance that the signal can be transmitted over balanced
twisted-pair. It also reduces RFI emissions.
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Converting Digital Data to Digital Signals, continued
Table 1.1 0 and Figures l. 9 through 1.13 show several coding methods.
Table 1.10
Coding methods
Line
Application
Encoding
Rate
Transmission
Method
Bandwidth
ISDN (basic rate)
ISDN (primary rate)
160 kb/s
1.544 Mb/s
2B1Q
Bipolar
40kHz
772kHz
HDSL
ADSL
2 x 784 kb/s
up to 7 Mb/s
2B1Q
DMTorCAP
196kHz
1.04 MHz
IBM System 3X
IBM System 3270
1.0 Mb/s
2.35 Mb/s
Manchester
Manchester
750kHz
1.76 MHz
IEEE 802.3
lOBASE-T
IOOBASE-TX
10008ASE-T
2.5G8ASE-T
5GBASE-T
lOGBASE-T
10 Mb/s
100 Mb/s
1000 Mb/s
2500 Mb/s
5000 Mb/s
10 Gb/s
Manchester
4858/MLT-3
8B/IQ4 PAM5
DSQl28/PAMl6
DSQ 128/PAM 16
DSQ128/PAM16
7.5 MHz
62.5 MHz
62.5 MHz
100 MHz
200 Mflz
400 MHz
IEEE 802.5 token ring
16 Mb/s
Differential
Manchester
12.0 MHz
ATM
ATM
ArM (STS-1)
ATM (STS-3)
12.96 Mb/s
25.6 Mb/s
51.8 Mb/s
155 Mb/s
CAP-2
4858
CAP-16
NRZ
12.96 Mliz
32MHz
29MHz
77MHz
TP-PMD
125 Mb/s
MLr-3
62.5 MHz
2B1Q =Two binary bits encoded into one quaternary
ADSL =Asymmetric digital subscriber line
ATM =Asynchronous transfer mode
CAP= Carrierless amplitude and phase
DMT = Discrete multitone
HDSL =High bit rate digital subscriber line
IBM@= International Business Machines
IEEE<V =Institute of Electrical and Electronics Engineers, Inc.@
ISDN =Integrated services digital network
MLT =Multilevel transition
NRZ =Non-return-to-zero
STS =Synchronous transport signal
TP-PMD =Twisted-pair physical media dependent
NOTE: Although frequencies are transmitted above the transmission bandwidth indicated,
most of the energy will not exceed this bandwidth.
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Converting Digital Data to Digital Signals, continued
Figure 1.9
Polar non-return-to-zero level
+V
_ _ _ _ _ _ _ Two-state
ov
-v
1
0
1
1
0
0
0
1
1
1
0
1
1
0
1
Figure 1.10
Bipolar AMI
0
1
1
0
0
1
0
0
0
0
1
1
0
+V
Two-state
ov
-v
Figure 1.11
Biphase Manchester
+V
__ _
ov
Two-state
-v
1
0
1
0
1
0
0
1
0
1
1
1
0
Figure 1.12
Two binary bits encoded into one quaternary (2B1Q)
v ,----
-
-
Coding map
11 -->
v
3
ov
10 -->
-----+-------~------~-----------------r­
-v
3-
v
v
3
01 -->
-v
00 -->
-v
-
3
Four-state
-v
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Converting Digital Data to Digital Signals, continued
Figure 1.13
MLT-3, also referred to as NRZI-3
+V
Three-state
ov
-v
0
1
1
1
0
1
1
0
0
1
0
1
1
1
0
Quadrature Amplitude Modulation (QAM)
QAM is a widely used modulation technique for sending digital data. QAM and its
derivatives are used in both mobile radio and satellite telecommunication systems. It is the
basis for DMT and similar schemes used in xDSL systems.
A QAM signal is composed of two sinusoidal carriers, each having the same frequency but
differing in phase by one quatier of a cycle (hence the term quadrature). One sinusoid is
called the I signal, and the other is called the Q signal.
Mathematically, these two signals are equivalent to a sine wave and a cosine wave. At the
transmitter, the I and Q carriers are amplitude modulated by bits selected from the data.
The two amplitude modulated carriers are then combined J()r transmission. The combined
signal is both amplitude and phase modulated by the data bits (e.g., data bits determine
both the amplitude and the phase of the transmitted signal). At the destination, the carriers
are separated; the data is extracted from each; and the data is converted into the original
modulating digital data.
Discrete Multitone (DMT}
DMT uses multicarrier modulation. A frequency band is sliced into several hundred (typically
256) sub-bands, each of which carries a signal modulated with part of the data stream. Data
rates can be adjusted with DMT by increasing the number of sub-bands and by varying the
number of bits carried in each sub-band.
8B/1Q4 PAMS Encoding
The 8B/l Q4 PAMS encoding scheme is specified in IEEE 802.3ab for use with 1OOOBASIYC
which uses all four cable pairs for simultaneous transmission in both directions. This is
accomplished through the use of echo cancellation and 8B/1 Q4 PAMS encoding. Each group
of eight bits (8B) is converted to one transmission of four quinary symbols (1 Q4) across four
balanced twisted-pairs. Each symbol represents two binary bits using PAMS modulation.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Digital versus Analog
The information transmitted by a telecommunications system can originate in two
fundamental forms---digital and analog. Digital data is represented by a string of bits,
whereas analog data (e.g., speech waveform) is represented by the continuous variation of the
data.
As previously discussed, an analog signal can be converted to an equivalent string of data bits
before transmission, the data bits can be transmitted, and the original analog signal can be
reconstructed from the data bits at the receiver. Alternately, the analog signal can be used to
directly modulate a carrier (e.g., AM, FM) without the conversion to and from digital data.
Generally, a larger bandwidth is required to transmit the analog information if it is
represented as digital data bits. However, using sophisticated digital encoding schemes and
complex signal processing techniques can offset this effect.
Sending digital data does offer one major advantage over sending analog data. If the digital
data stream is recovered before the effects of attenuation and added chatmel noise become so
large that bit errors occur, then the digital data can be recovered exactly. Thus, digital data can
be transmitted (noise free) over essentially unlimited distances if the digital data is received
and regenerated at intervals before it is degraded by added noise.
The situation is different for analog data. Added noise within the spectrum of an analog
data signal transmission cannot be removed. To send analog data over long distances, the
transmission signal must be amplified at intervals to overcome the effects of attenuation.
However, the amplifier will amplify the in-band added noise as well as the analog data signal.
Thus, over a long distance, the effects of added noise will be cumulative.
An additional advantage of digital is that digital transmission systems can transmit analog
data-by first converting it to equivalent digital data-but a transmission system that is
designed to transmit analog data cannot efficiently handle high-speed digital data.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Types of Transmission Circuits
Overview
Transmission circuits are generally classified as:
• Simplex.
• Half-duplex.
• Full-duplex.
These terms apply to any transmission media. Similar terms are used differently in radio and
microcomputer communications. The following definitions clarify the use of these terms in
telecommunications.
Simplex
Simplex is a term used to describe the transmission of signals in one direction only. A simple,
but familiar, example of simplex transmission is a public address system without twoway speakers. The signal, which represents the speaker's voice, is carried to a number of
loudspeakers. There is no path for listeners to respond.
Half-Duplex
Half-duplex is a term used to describe the transmission of signals in either direction, but only
in one direction at a time.
This requires agreement between stations and typically employs a:
• Push-to-talk switch arrangement on voice circuits.
• Signaling protocol.
A home intercom is a familiar example of a half-duplex operation.
Full-Duplex
Full-duplex is a term used to describe the transmission of signals in both directions at the
same time. All telephone lines are full-duplex, allowing both parties to talk simultaneously.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Asynchronous and Synchronous Transmission
Overview
For the purposes of this section, the terms asynchronous and synchronous refer to different
methods of timing digital signals for transmission. The equipment involved generally dictates
the method used.
Asynchronous Transmission
Asynchronous transmission occurs without a precise time relationship in the signal characters
or the bits that represent them.
Each character of the information:
• Is sent without a precise time relationship between it and any other character of information.
• Carries with it start and stop signals.
Asynchronous transmission is a popular method of telecommunications among
microcomputer users because of a common standardized interface and protocol between
machines.
Asynchronous transmission is less etiicient than synchronous transmission because it requires
the addition of some combination of start and stop bits to the data stream, but it is not difficult
to implement in systems at speeds less than 20 kb/s.
Synchronous Transmission
Synchronous transmission is performed by synchronizing the data bits in phase or in
unison with equally spaced clock signals or pulses. Both the sender and the receiver must
have timing and synchronizing capabilities. The clocking pulses prevent confusion of the
characters in the data stream.
Synchronous transmission is more efficient than asynchronous transmission because no start
and stop bits are required. It is used with digital baseband transmission systems.
TDMM, 14th edition
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© 2020 IHCSI®
Chapter 1: Principles of Transmission
D
ital Hiera
Overview
Several techniques can be taken in transmission to maximize the number of communications
channels available. One of the most common is to combine multiple digital data streams into
one data stream using TOM.
NOTE: Refer to the previous discussion ofTDM in this chapter.
Integrated Services Digital Network (ISDN)
ISDN uses digital transmission at a basic or primary rate, depending upon the application.
Basic rate ISDN:
• Is intended for residential and small business users.
• Uses a digital signal consisting of two 64 kb/s B channels (assigned for voice and data) and
one 16 kb/s D channel (assigned for signaling and packet data).
• Has a total information capacity of 144 kb/s (line rate = 160 kb/s ).
Primary rate ISDN North America:
• Is intended for large business users.
• Has a total information capacity of 1.536 Mb/s (line rate= 1.544 Mb/s ).
• Uses a digital signal consisting of23 B channels and one D channel, each operating at
64 kb/s.
Primary rate ISDN can be implemented over repeated T I carrier or HDSL facilities. It also
may be embedded in the higher rate transmission systems. ·
Primary rate ISDN Europe:
• Ts intended for large business users.
• Has a total information capacity of 1.92 Mb/s (line rate= 2.048 Mb/s).
• Uses a digital signal consisting of 30 B channels and one D channel, each operating at
64 kb/s.
Primary rate ISDN can be implemented over repeated El carrier or HDSL facilities. It also
may be embedded in the higher rate transmission systems.
© 2020 BICSI®
TDMM, 14th edition
Chapter 1: Principles of Transmission
Digital Subscriber line (DSl)
Several related telecommunications technologies fall under the broad category of DSL
solutions (also referred to as xDSL).
Variants ofDSL technology include:
• HDSL.
•SDSL.
• ADSL, ADSL2, ADSL2+.
• RADSL.
• VDSL.
In general terms, all of these solutions are oriented toward providing high-speed, high-quality
transmission of data, voice, and video over existing balanced twisted-pair telephone lines.
High Bit-Rate Digital Subscriber line (HDSl)
HDSL is a way oftransmitting DSl rate signals over balanced twisted-pair cable. HDSL
requires no repeaters on lines less than ;::;3600 m (11,811 ft) for 24 AWG.
Using advanced modulation techniques, HDSL transmits 1.544 Mb/s (DS I) or 2.048 Mb/s
(El) in bandwidths of less than 500kHz, both upstream and downstream. Depending upon
the specific technique, HDSL requires two twisted-pairs for OS 1 and three twisted-pairs for
E I, each operating at half or third speed.
HDSL has effectively been replaced by SDSL and other xDSL technologies.
Symmetrical Digital Subscriber line (SDSl)
SDSL is a single-pair version ofHDSL, transmitting up to DS I rate signals over a single
balanced twisted-pair. SDSL has an important advantage compared with HDSL. SDSL suits
the market for individual subscriber premises that are often equipped with only a single
telephone line.
SDSL is desired for any application needing symmetrical access (e.g., servers, power
remote LAN users) and therefore complements ADSL (see the following section on ADSL
Technologies). It should be noted, however, that SDSL would not reach much beyond
;::;3000 m (9842 ft), a distance over which ADSL achieves rates up to 6 Mb/s.
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Chapter 1: Principles of Transmission
Asymmetric Digital Subscriber line (ADSl) Technologies
ADSL technology is asymmetric-it allows more bandwidth downstream (server to client)
than upstream (client to server).
An ADSL circuit connects an ADSL modem on each end of a single balanced twisted-pair
telephone line, creating three infon11ation channels-a high-speed downstream channel, a
medium-speed duplex channel, and a POTS channel.
The POTS channel is split otT from the digital modem by filters, thus guaranteeing
uninterrupted POTS, even if ADSL fails. The high-speed downstream channel ranges from
1.5 to 8 Mb/s, while the upstream rate for ADSL varies from about 128 kb/s to just over
1 Mb/s.
Good Internet performance requires a down-to-upstream ratio of at least 10: 1. ADSL is ideal
for Internet connections, video on demand, and remote LAN access-typical applications that
are found in the home.
Several ADSL technologies have been defined in standards (see Table 1.11).
Table 1.11
ADSL standards
Standard Name
Standard Type
Downstream
Upstream
lTU 0.992.1
ADSL (G.DMT)
8 Mb/s
1.0 Mb/s
ITU 0.992.2
ADSL Lite
1.5 Mb/s
0.5 Mb/s
ITU 0.992.3/4
ADSL2
12 Mb/s
1.0 Mb/s
TTU 0.992.3/4 Annex J
ADSL2
12 Mb/s
3.5 Mb/s
ITU 0.992.5
ADSL2+
24 Mb/s
1.0 Mb/s
ITU 0.992.5 Annex L
ADSL2+
24 Mb/s
3.5 Mb/s
ADSL = Asymmetric digital subscriber line
DMT = Discrete multitone modulation
ITU = International Telecommunication Union
ADSL modems provide data rates consistent with North American and European digital
hierarchies and can be purchased with various speed ranges and capabilities. ADSL modems
will accommodate ATM transport with variable rates and compensation for ATM overhead as
well as TP protocols.
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Chapter 1: Principles of Transmission
Asymmetric Digital Subscriber line (ADSl) Technologies, continued
Downstream data rates depend on a number of factors, including the length of the balanced
twisted-pair cable, its wire gauge, the presence of bridged taps, and crosstalk interference.
Ignoring bridged taps, ADSL will perform as shown in Table I. 12.
Table 1.12
ADSL performance
Data Rate
AWG
Distance
1.5 or 2 Mb/s
24AWG
;::;5.5 km (18,000 ft)
1.5 or 2 Mb/s
26AWG
;:::o4.6 km ( 15,000 ft)
6.1 Mb/s
24AWG
;:::o3.7 km (12,000 ft)
6.1 Mb/s
26AWG
;:::o2. 7 km (9000 ft)
8 Mb/s
24AWG
;:::o2.0 km (6500 ft)
Many applications envisioned for ADSL involve digital compressed video. MPEG movies
require 1.5 to 3.0 Mb/s. As a real-time signal, digital video cannot use link or network level
error control procedures commonly found in data telecommunications systems. Therefore,
ADSL modems incorporate FEC that dramatically reduces errors caused by impulse noise.
Rate-Adaptive Digital Subscriber line (RADSl)
RADSL is the rate-adaptive variation of ADSL. Transmission speed is rate adaptive based on
the length and signal quality of the line. RADSL products have the option to select the highest
practical operating speed automatically or as specified by the AP.
RADSL allows the AP to adjust the bandwidth of the DSL link to fit the need of the
application and to account for the length and quality of the line. Additionally, RADSL extends
the possible distance from the subscriber to the AP facility, thus increasing the percentage of
users served by DSL services.
Very High Bit-Rate Digital Subscriber line (VDSl)
While VDSL has not achieved the same degree of definition as ADSL, it has advanced
enough to discuss realizable goals, beginning with data rate and range.
Downstream rates derive from submultiples of the SONET and SDH canonical speed of
155.52 Mb/s, namely 51.84 Mb/s, 25.92 Mb/s, and 12.96 Mb/s. Each rate has a corresponding
target range over existing OSP (see Table 1.13).
Table 1.13
VDSL data rate and target range
Data Rate
Target Range
12.96to 13.8 Mb/s
;:::o(500
25.92 to 27.6 Mb/s
;:::oJ000m(3281 ft)
51.84 to 55.2 Mb/s
;:::o300 m (984 ft)
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Chapter 1: Principles of Transmission
Very High Bit-Rate Digital Subscriber line (VDSL), continued
It is possible to achieve greater distance using a broadband PIC cable. For example, 52 Mb/s
can be achieved over ;:::;1000 m (3281 ft) using broadband PIC 22 AWG cabling.
Upstream rates under discussion fall into three general ranges:
• 1.6 to 2.3 Mb/s
• 19.2 Mb/s
• Equal to downstream
Early versions ofVDSL will typically incorporate the slower asymmetric rate. Higher upstream and symmetrical configurations may only be possible for short lines.
Like ADSL, VDSL may transmit compressed video, which is a real-time signal unsuited to
error retransmission schemes used in data communications. To achieve error rates compatible
with compressed video, VDSL will need to incorporate FEC with sufficient interleaving to
correct all errors created by impulsive noise events of some specified duration. Interleaving
introduces delay in the order of 40 times the maximum length correctable impulse.
In many ways, VDSL is simpler than ADSL. Shorter lines impose far fewer transmission
constraints, so the basic transceiver technology can be less complex, even though it is 10
times faster.
Currently, VDSL targets only ATM network architectures, obviating channelization, and
packet-handling requirements imposed on ADSL. VDSL is planned to use passive network
terminations, enabling more than one VDSL modem to be connected to the same line at
customer premises in much the same way as extension telephones connect to home cabling
for POTS.
VDSL was called VASDL or BDSL or even ADSL prior to June 1995 when VDSL was
chosen as the official title. The other terms still linger in technical documents created before
that time and in media presentations unaware of the convergence.
The European counterpart to VDSL has temporarily appended a lowercase ''e" to indicate that
the European version ofVDSL may be slightly different from the U.S. version. This is the
case with both HDSL and ADSL although there is no convention for reflecting the differences
in the name. The differences are sufficiently small (mostly concerning data rates) that silicon
technology accommodates both.
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Chapter 1: Principles of Transmission
Video Transmission
Baseband Analog
A baseband analog video signal is a continuous varying signal whose magnitude and
frequency represent the video content (e.g., luminance, chrominance, synchronization). A
baseband video signal contains all the necessary information to reproduce a picture, but it
does not modulate an RF carrier.
Two terms commonly used to describe different types of baseband signaling are:
• Composite.
• Component.
Composite Format
ln the composite format, the analog signal contains all the components necessary to construct
a monochrome or color picture, but it contains no audio information. This type of signal
is typically found as the output from a digital recording device, TV monitor, camera, or
camcorder. Figure 1.14 illustrates the composition of the signal.
Figure 1.14
Composite video
White
Luminance
1 Vpp
U
~IHII~IH~~11m-
V&H sync
Chromi nance
V&H sync= Vertical and horizontal synchronization
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Chapter 1: Principles of Transmission
Baseband Analog, continued
Component Format
A color video picture is made up of three colors (red, green, and blue), which are mixed in
varying intensities to create a complex image. Component video, also called RGB video,
keeps separate the three-color components of the image using three cables to carry the video
signal.
RGB signals separate the primary color information from the luminance signal, which
minimizes crosstalk and permits higher resolutions. RGB signaling is typically used for highend graphic workstations where the need for higher-quality imaging is required.
Broadband Video
The term broadband video refers to composite baseband video and audio signals that are
amplitude and frequency modulated, respectively, with an RF carrier in accordance with
the video and audio information that need to be conveyed (e.g., CATV). Each RF carrier
represents a TV channel. RF carriers are separated by 6 to 8 MHz.
NOTE: See Chapter 13: Audiovisual Systems for more information.
Balanced Twisted-Pair Media Implementation
Video signals traditionally have been transported using coaxial and optical fiber cables.
Because of increased requirements for the transmission of video signals in commercial
applications, support for analog video transmission, along with the associated audio
component, using structured balanced twisted-pair cabling systems has been developed.
Baseband composite signaling can be supported over category 3/class C or higher cabling in
excess ofo::l 00 m (328ft). RGB component signals are supported with category 3/class Cor
higher cabling for a minimum ofo::J 00 m (328 tt) using passive media adapters.
Broadband analog CATV signaling can be implemented on category Se/class D or higher
balanced twisted-pair cabling. For example, category Se/class D cabling can support CATV
downstream delivery between 55 MHz and 550 MHz over limited distances.
Category 6/class E or higher cabling provides better performance because of lower signal
loss, higher SNR, and higher noise immunity. lt can support more broadband channels or
longer distances than category Se/class D.
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Chapter 1: Principles of Transmission
Transmission Line Con
Overview
An idealized transmission line consists of two conductors that arc separated by a dielectric
material uniformly spaced over its length.
Figure 1.15 illustrates a transmission line consisting of two conductors of a diameter (d) that
are physically separated by a distance (D). A balanced voltage (V) is applied between the two
conductors. Equal and opposite currents (I) flow in each conductor.
Figure 1.15
Two-conductor transmission line
d
+V/2
D
R
I
Load
•rn
.J
-V/2
d ==
D=
I==
R ==
V=
Diameter (in m)
Distance (in m)
Equal and opposite currents (in A)
Resistance of the line (in Q)
Voltage (in V)
The earliest functional model of a transmission line was based on resistive loss
(see Figure 1.16). The voltage drop in each conductor is directly proportional to the current
flow and the resistance of the line (R) in ohms. The larger the conductor diameter, the lower
the resistance. The higher the conductivity of the conductor material, the lower the resistance.
An additional factor, conductance (G), represents leakage current through a nonideal
dielectric. G is the reciprocal of the resistance between the two-line conductors and is always
expressed this way for calculation purposes.
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Chapter 1: Principles of Transmission
Overview, continued
Figure 1.16
Resistive model
R/2
R/2
G = Conductance (in S)
R = Resistance of the line (in Q)
As longer transmission distances and higher frequencies were attempted, it became clear
that the simple resistive model was not adequate. An additional factor helped in explaining
observed limitations in distance and bandwidth.
The applied voltage between conductors causes a movement of electric charge such
that equal and opposite charges are deposited on the surface of each conductor
(see Figure 1.17). The distribution of electric charge sets up an electric field (E) in the
dielectric space surrounding each conductor. This electric field is typically modeled as
capacitance (C). Units of capacitance are measured in F.
Figure 1.17
Capacitance model
+V/2
C = Capacitance (in F)
E = Electric field (in V/m)
V = Voltage (in V)
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Overview, continued
As further progress was made in transmission technology, it became apparent that even the
combined resistive and capacitive models were not adequate. Another factor needed to be
considered.
The flow of current sets up a concentric magnetic field (B) that surrounds each conductor
(see Figure 1.18). The magnetic field is reinforced in the space between the conductors and
is diminished in the region outside both conductors. A larger separation between conductors
results in a larger magnetic field and hence a higher inductance. The magnitude of the
inductance also depends on the magnetic permeability of the dielectric material or any
magnetic coating surrounding the conductors.
A material of high permeability results in a higher magnetic field intensity for a given
current and, therefore, a higher inductance. The magnetic field effects can be modeled as an
inductance. Units of inductance are measured in H.
Figure 1.18
Inductive model
Conductor
•
B
I So:ce
8
L
L
~
Conductor
B = Concentric magnetic field (in T)
I= Equal and opposite currents (in A)
L = Inductance (in H)
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Chapter 1: Principles of Transmission
Overview, continued
A transmission line can be represented by an electrical circuit containing only passive
components that are arranged in a ladder network. The ladder network is built up of cascaded
sections, each with a very small length (f1x), consisting of a series resistance and a series
inductance in parallel with a mutual capacitance and a mutual conductance (see Figure 1.19).
These distributed components are called the primary transmission parameters.
The primary transmission parameters are defined as follows:
• The series resistance R, expressed in ohms, is the loop resistance of a pair of conductors for
an incremental length (f1x). Series resistance is related to the dimensions and separation of
conductors.
• The series inductance L, expressed in H, is the loop inductance of a pair of conductors for
an incremental length (f1x). Series inductance is related to the dimensions and separation of
conductors.
• The mutual capacitance C, expressed in F, is capacitance between a pair of conductors for
an incremental length (f1x). Mutual capacitance is related to the dimensions and separation
of conductors and to the dielectric constant of the insulation and jacket materials.
• The mutual conductance G, expressed in S, is the conductance between a pair of conductors
for an incremental length (f1x). Mutual conductance is related to the dielectric loss of the
insulation and jacket materials.
Figure 1.19
Primary transmission line parameters
Section of line
1/2 Rune
More
line
sections
1/2 LUne
[]]
1/2 RUne
© 2020 BICSI®
1/2 LUne
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Overview, continued
The electric and magnetic fields, along with the circuit currents and voltages, arc not
independent but are intrinsically related through Maxwell's equations.
NOTE: A discussion of Maxwell's equations is outside the scope of this chapter. ft is
sufficient to know that it forms the foundation of all EM wave theory.
These primary parameters (R, L, G, and C) can be calculated t!·om the knowledge of the
physical design of the cable.
These design relationships tend to be complex and will depend on the:
• Cable geometry.
• Properties of the cable materials.
• Frequency of the applied signal.
ft is not essential to know these relationships to appreciate transmission line concepts.
NOTE: For more information about cable design and transmission, see the Bibliography at
the end of this manual.
The secondary parameters of a transmission line are:
• Calculated from the primary parameters.
• Obtained by direct measurement.
The secondary parameters can be used to model the behavior of an electrical signal as it
passes through the cable. For this purpose, the cable can be considered as a black box. The
output response can be measured as a function of the applied signal for different terminating
conditions. Figure 1.20 illustrates the general transmission model.
Figure 1.20
General transmission model
zs
I.I
I
Transmission
media
Source
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L---+
Z.
In
1-52
0
v
0
Load
© 2020 BICSI®
Chapter 1: Principles of Transmission
Characteristic Impedance
Characteristic impedance corresponds to the input impedance of a uniform transmission line
of infinite length:
It also corresponds to the input impedance of a transmission Iinc of finite length that is
terminated in its own characteristic impedance. fn general, the characteristic impedance
has both a resistive and reactive component. Characteristic impedance is a function of the
frequency of the applied signal, but it is unrelated to the cable length.
Maximum power is transferred from the source to the load when the source impedance (Z)
and the terminating impedance (Z1) are equal to the complex conjugate of the transmission
line characteristic impedance (ZJ
NOTE: Two impedances are complex conjugates if they have the same resistive component
and their reactive components have opposite signs.
Under these conditions, all the energy is transmitted and none of the energy is reflected back
at the cable termination. At very high frequencies, the characteristic impedance asymptote
leads to a fixed value that is resistive. For example, coaxial cables have an impedance of
50 or 75 ohms at high frequency. Typically, balanced twisted-pair telephone cables have an
impedance of I 00 ohms above I MHz.
Attenuation
Attenuation corresponds to the ratio in decibels ofthe output power (or voltage) to the input
power (or voltage) when the load and source impedance are matched to the characteristic
impedance of the cable.
Where the terminations are perfectly matched, the ratio of output to input power (or voltage)
is called attenuation. Practical attenuation measurements yield values that are higher than the
attenuation, depending on the degree ofmismatch. When evaluated in terms of voltage ratio,
attenuation can be determined according the expression below.
Where:
Attenuation (dB)
-20 log (
~0~'1
)
Where:
© 2020 BICSI®
Yin
Input voltage (in V)
Vout
Output voltage (in V)
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Chapter 1: Principles of Transmission
Crosstalk
Crosstalk is signal interference between cable pairs, which may be caused by a pair picking
up unwanted signals from either:
• Adjacent pairs of conductors.
• Nearby cables.
For example, this interference can result from the magnetic field that surrounds any currentcarrying conductor. The crosstalk interference can be intelligible or unintelligible, depending
on the coupling modes.
Nominal Velocity of Propagation {NVP)
A signal traveling from the input to the output is delayed in time by an amount equal to the
length of cable divided by the velocity of propagation (u) for the transmission medium. In the
case of an ideal transmission line consisting of two conductors in free space, the velocity of
propagation is equal to the velocity oflight in a vacuum (c).
For practical cables, the velocity of propagation depends on the properties of the dielectric
materials surrounding the conductors. At very high frequencies, u asymptote tends toward a
constant value.
Where:
u =
c
-{;£
Where:
c
Velocity of light in a vacuum
~t =
Relative permeability of dielectric
£
=
Relative permittivity of dielectric
NOTE: For balanced twisted-pair cables, an NVP for a specific cable design is provided by
the cable manufacturer and is expressed as a percentage of the speed of light. For
example, NVP = 62 percent or .62c. Typical values range from .56c to .74c for
I 00-ohm balanced twisted-pair cables range.
Propagation Delay
The development of new high-speed applications using multiple pairs for parallel
transmission has shown the need for additional transmission specifications (e.g., propagation
delay, delay skew) for I 00 ohm, 4-pair cabling systems.
The following equation is used to compute the maximum allowable propagation delay
between I MHz to the highest referenced frequency for a given category of cable.
Delay (ns/lOO m)
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Chapter 1: Principles of Transmission
Delay Skew
Delay skew is the difference in propagation delay between any pairs within the same cable
sheath. The delay skew between the fastest and slowest pairs in category 6A/class EA and
category 5e/class D cabling shall not exceed 45 ns at :::;J 00 m (328ft [see Table 1.14]).
Table 1.14
Propagation delay/delay skew
Maximum Delay
ns/;:::100 m (328 ft)
Minimum Velocity
of Propagation
Maximum Delay
Skew ns/;:::100 m
(328ft)
570
58.5%
45
10
545
61.1%
45
100
538
62.0%
45
Frequency
MHz
Reflection Coefficient
Consider the case where the terminating impedance is not the same as the characteristic
impedance of a cable (e.g., Z 1 :f ZJ ln this case, a signal will be partly reflected at the cable/
load junction.
The magnitude of the reflection is given by the reflection coefficient (p). IfZt < Z 0 , then the
polarity of the reflected wave is inverted; if Z 1 > Z 0 , then the polarity of the reflected wave is
not inverted.
Reflection coefficient (p) = (Zt - Z 0 )/(Zt + Z 0 )
Return loss
Return loss is the ratio between the transmitted power and the reflected power expressed in
dBs. The better the impedance matching, the lower the reflected energy and the higher the
return loss. Return loss can be determined as follows:
Where:
Return loss (dB)
Where:
P reflected= Signal power of the reflected signal (in W)
Pin= Signal power of the injected signal (in W)
Return loss is an important parameter for gigabit networks that employ parallel, full-duplex
transmission over all four pairs because each pair will carry information in both directions,
the same as an analog telephone line. Any impedance mismatch between components will
result in signal reflections (echoes) that appear as noise at the receiver. Although this noise
is partially canceled in the equipment, it can be a significant contributor to the overall noise
budget.
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Chapter 1: Principles of Transmission
Signal-to-Noise Ratio (SNR)
SNR is the ratio of the level of the received signal at the receiver-end and the level of the
transmitted signal. The level of the received signal must significantly exceed the level of
the received noise for a feasible communication condition. SNR can be determined by the
following expression.
Where:
SNR (dB)
Where:
V .
= Level of the noise voltage at the receiver-end (in V)
Vsignal
=
!lOISC'
Level of the transmitted signal (in V)
Attenuation-to-Crosstalk Ratio (ACR)
The ACR is a ratio obtained by subtracting the attenuation (dB) from NEXT (dB). ACR is
normally stated at a given frequency.
It can be calculated as follows:
ACR =Minimum NEXT loss- maximum attenuation
Power Sum Attenuation-to-Crosstalk Ratio (PSACR)
The PSACR is a ratio in decibels determined by subtracting the attenuation from PSNEXT
loss.
lt can be calculated as follows:
PSACR = Minimum PSNEXT loss- maximum attenuation
Power Sum Attenuation-to-Alien-Crosstalk Ratio at the Near End (PSAACRN)
The PSAACRN is a ratio in decibels determined by subtracting the attenuation from the
PSANEXT loss between cables or channels in close proximity.
It can be calculated as follows:
PSAACRN = Minimum PSANEXT loss- maximum attenuation
Power Sum Attenuation-to-Alien-Crosstalk Ratio at the far End (PSAACRf)
The PSAACRF is a ratio in decibels determined by subtracting the attenuation from the
PSAFEXT loss between cables or channels in close proximity.
It can be calculated as follows:
PSAACRF = Minimum PSAFEXT loss- maximum attenuation
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Chapter 1: Principles of Transmission
Balanced Twisted-Pair Performance
Balanced twisted-pair cables are commonly used for data telecommunications in buildings.
Successful implementation of the balanced twisted-pair approach for LAN installations
requires proper design, installation, and testing to ensure that channel performance
requirements are met. A channel, as defined in the cabling standards, includes all cables,
cords, and connectors from an equipment connection at one end to the equipment connection
at the other end.
The transmission characteristics of telecommunications cables, cords, and connectors depend
on the frequency of the applied signal. These differences are most apparent at frequencies
above one MHz. It is important for the ICT distribution designer to be able to assess the
capabilities of different transmission media for a given application.
The transmission parameters of greatest importance include the:
• Signal attenuation as a function of frequency.
• Signal reflections at terminations.
• Amount of noise relative to the received signal.
The noise can be coupled into the cable from adjacent circuits sharing the same sheath
(crosstalk coupling) or from external influences.
Balanced twisted-pair cables have a nominal characteristic impedance of 100 ohms at
100 MHz. The improvement in attenuation for high-performance cables is realized through
improved design and materials. Likewise, an improvement of upward of 10 dB in crosstalk
performance is attained through better balance and pair-twist optimization. These balanced
twisted-pair cables provide increased signal-to-noise margins, which equate to higher data
throughput (fewer bit errors), a longer reach, or higher transmission rate capability.
NOTE: Refer to Appendix A: Codes, Standards, Regulations, and Organizations at the end of
this manual for the relevant cable and component standards for a specific country or
regron.
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Chapter 1: Principles of Transmission
Balanced Twisted-Pair Channel Performance
Channel Model
Figure 1.21 shows a channel and the cabling components that determine the channel
performance.
The components that may make up the channel consist of a:
• Telecommunications outlet/connector.
• Balanced twisted-pair cable
of~90
m (295ft).
• Cross-connect system.
• Equipment and patch cords.
• CP.
• liCP.
• TP.
• MUTOA.
Figure 1.21
Example of a channel test conAguration
Telecommunications
outlet/connector
To test
{
Cord or jumper
CP or TP
connector
Horizontal
Cross-connect
1 + - - - - - - - - - - - ~ 100 m (328 f t ) - - - - - - - - - - 1 . , . 1
CP = Consolidation point
TP = Transition point
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Chapter 1: Principles of Transmission
Performance Parameters
The most important parameters that affect performance are insetiion loss, PSNEXT loss,
and return loss in the case of bidirectional transmission. Other parameters (e.g., velocity of
propagation, delay skew, longitudinal conversion loss, attenuation deviation, PSELFEXT
[also called PSACRF]) are also important for certain higher speed applications where more
complex encoding schemes and duplex balanced twisted-pair transmissions are implemented.
For 1OGBASE-T applications (IEEE 802.3an standard), alien crosstalk parameters, including
PSANEXT loss and PSAACRF, are specified.
Insertion loss Performance limits
Channel insertion loss is equal to the sum of the attenuation of the various components in the
test channel, plus all the mismatch losses at cable and connector interfaces, and the increase
in attenuation adjusted for temperature. In the worst case, the channel shown in Figure 1.21
consists of:::::-;90 m (295ft) ofhorizontal cable and up to a total of:::::-;10 m (33ft) of equipment
and patch cords combined. Generally, patch cords are of flexible stranded construction,
thereby presenting higher losses per meter or foot than horizontal cables.
All components must meet the minimum attenuation requirements of the appropriate standard
for balanced twisted-pair category or class.
NOTE: In many documents, the terms attenuation and insertion loss are used interchangeably.
Strictly speaking, attenuation is a measure of the signal loss under ideal termination
conditions where the load and source impedance matches the cable characteristic
impedance and all components are exactly matched in impedance.
Near-End Crosstalk (NEXT) loss limits
The NEXT loss in the channel is the vector sum of crosstalk induced in the cable, connectors,
and patch cords.
NEXT loss is dominated by components in the near zone (less than :::::-;20m [66 ft]).
To verify performance, measure NEXT loss from both the TR and the telecommunications
outlet/connector. All components must meet the minimum NEXT requirements for the
appropriate standard for balanced twisted-pair category or class.
Power Sum Equal level far-End Crosstalk (PSElfEXT) loss limits
PSELFEXT is a computation of the unwanted signal coupling from multiple transmitters at
the near end into a pair measured at the far end. PSELFEXT is calculated in accordance with
the power sum algorithm. All components must meet the minimum PSELFEXT requirements
for the appropriate standard for balanced twisted-pair category or class.
© 2020 BICSI®
TDMM, 14th edition
Chapter 1: Principles of Transmission
Return loss limits
Return loss is a measure of the reflected energy caused by impedance mismatches in the
cabling system. All components must meet the minimum return loss requirements for the
appropriate standard for balanced twisted-pair category or class.
Power Sum Attenuation-to-Crosstalk Ratio (PSACR)
The balanced twisted-pair channel performance specified previously is determined from
transmission measurements on cables and termination hardware. These measurements
are performed in the frequency domain. The range of frequencies that can be successfully
transmitted for a given distance determines the available channel bandwidth in MHz for a
specified channel.
Different criteria can be used to determine the available bandwidth. One such criterion is the
minimum signal level at the output of a channel relative to the peak NEXT noise level. This
criterion is defined as PSACR.
To ensure an acceptable BER, the signal should be a reasonable replica of the transmitted
signal. Attenuation is a decrease in signal magnitude. Higher frequency components of the
digital signal incur more attenuation over a given balanced twisted-pair channel. The net
effect is not only a reduction in amplitude, but also a change in the shape of the transmitted
signal as it appears at the receiver. Additionally, NEXT noise adds abrupt variations in the
signal magnitude. The reliability of the receiver to detect changes in the signal waveform is
affected by these signal impairments.
Concept of Bandwidth
There is a fundamental relationship between the bandwidth of a channel expressed in Hz and
the data rate expressed in b/s. The traffic flow on a major highway provides a good analogy
to illustrate the concept of bandwidth versus data rate. 'T'he bandwidth is similar to the width
of the highway and the number of lanes of traffic. The data rate is similar to the traffic flow or
the number of vehicle crossings per hour. One way to increase the traffic flow is to widen the
highway. Another way is to improve the road surface and eliminate bottlenecks.
Similarly, it is possible to support a higher data rate for any channel by using a more elaborate
line-encoding scheme to pack more bits of information per Hz of available bandwidth. More
elaborate line encoding requires a higher SNR, which is like a smoother road surface in this
analogy.
The available bandwidth is commonly determined as the frequency range where the SNR
is positive. For most LAN systems today, the dominant noise source is NEXT interference
between all transmit pairs and a receive pair. lf all four pairs are employed for parallel
transmission, then the total NEXT noise is PSNEXT.
In this case:
• SNR is the PSACR when other noise sources are negligible and where
PSACR = PSNEXT- attenuation.
• Bandwidth is the frequency range where PSACR > 0.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Summary
The key pcrfonnancc drivers of balanced twisted-pair channels arc:
• Insertion loss.
• PSNEXT loss.
• PSELFEXT loss.
• Return loss for bidirectional applications.
NEXT and PSNEXT are of particular concern in network configurations of balanced twistedpair cables. When measuring insertion loss, the ICT distribution designer needs to know
that the cable length and signal frequency affect the amount of Joss. However, NEXT and
PSNEXT occur at the beginning of the channel and do not change appreciably as the cable
gets longer.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Balanced Twisted-Pair Permanent link Performance
Permanent link Model
Figure 1.22 depicts a permanent link model.
Figure 1.22
Permanent link test configuration
Telecommunications
outlet/connector
(
-
Q
Q
TR
CP or TP
connector
"'--'
n
Horizontal
~-
;:o::90 m (295 ft)
...
CP = Consolidation point
TP = Transition point
TR = Telecommunications room
Permanent link consists of up to ::::::90 m (295ft) horizontal cabling, including a connector at
each end.
Balanced Twisted-Pair Patch Cords and Cross-Connect Jumpers
Cross-connect jumpers and cables used for patch cords shall meet the same transmission
performance requirements as those specified for I 00-ohm horizontal cabling with the
following exceptions:
• Stranded conductor cable has more attenuation than solid conductor cable.
• A requirement in the category 5e, category 6, category 6A, category 7, and higher standard
is a patch cord return loss test. The patch cord is often a weak link in a cabling system. The
patch cord return loss test requires that the patch cord be tested before and after mechanical
handling to ensure that the impedance remains stable and within tight limits.
A deviation of greater than ± 5 ohms above a nominal impedance of 100 ohms can result in
a failure. It had been observed in practice that many category 5 stranded patch cords tended
to exhibit large swings in impedance when flexed or handled. Category 5e and category 6/6A
patch cord designs are optimized to ensure stable return loss performance.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Balanced Twisted-Pair
ications
Design Considerations
As transmission speeds increase and users migrate to higher performance cabling, it is
impmiant for the industry to provide guidance on the cabling available for data applications.
The transmission categories of all components used in the same cabling system must be
matched to provide a consistently high level of reliability and transmission performance.
'T'he development of new high-speed applications using multiple pairs for parallel
transmission has shown a need for additional transmission requirements (e.g., propagation
delay, delay skew).
Exercise caution when using cables with mixed insulation since the velocity of propagation
can vary with the insulation used, and the skew between pairs may be excessive for some
high-speed applications.
'T'o determine the overall suitability of the cabling described for specific applications, the ICT
distribution designer should also consult with the:
• Cabling systems suppliers.
• Equipment manufacturers.
• Systems integrators.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
100-0hm Balanced Twisted-Pair Performance Category
Balanced twisted-pair cabling performance is described using a scale based on installed
systems (ISO classes) or individual components (ISO categories). The TIA defines installed
systems and individual components by categories.
Table 1.15 provides both ISO and TIA designations for cabling system and individual
component performance. While category 3/class Cis the minimum acceptable performance
for network cabling, category 5e/class D is the minimum recommended by most standards.
Category 6/class E or higher cabling represents BICSI best practices.
Table 1.15
Balanced twisted-pair cabling channel performance
ISO Categories/Classes
Characterization
TIA Categories
Frequency
Category 3/class C
Category 3
l6MHz
Category 5/class D
Category 5e
100 MHz
Category 6/class E
Category 6
250 MHz
Category 6A/class EA
Category 6A
500 MHz
Category 7/class F
N/A
600 MHz
Category 7A/class FA
N/A
lOOOMHz
Category 8.1, 8.2/class I, II
Category 8
2000 MHz
ISO == International Organization for Standardization
N/ A == Not applicable
TIA == Telecommunications Industry Association
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
100-0hm Balanced Twisted-Pair Performance Category, continued
Table 1.16 lists applications supported using 100-ohm balanced twisted-pair cabling.
Table 1.16
Applications supported using 100-ohm balanced twisted-pair cabling
Application
Specification Reference
Date
Additional Name
Class A (defined up to l 00 kHz)
PBX
National requirements
X.21
ITU-T Recommendation X.21
1994
V.ll
JTU-T Recommendation X.2J
1994
Class B (defined up to 1 MHz)
SO-Bus (extended)
ITU-T Recommendation 1.430
1993
ISDN Basic Access
(Physical Layer)
SO Point-to-Point
ITU-T Recommendation 1.430
1993
ISDN Basic Access
(Physical Layer)
S 1/S2
ITU-T Recommendation l.431
1993
ISDN Primary Access
(Physical Layer)
CSMA/CD I BASES
ISO/IEC 8802-3
2000
Star Ian
Class C (deil.ned up to 16 MHz)
CSMA/CD 1OBASE-T
ISO/JEC 8802-3
2000
CSMA/CD lOOBASE-T2
ISO/IEC 8802-3
2000
Fast Ethernet
CSMA/CD 1OOBASE-T4
ISO/IEC 8802-3
2000
Fast Ethernet
IS LAN
lSO/lEC 8802-9
1996
Integrated Services
LAN
Demand priority
lSO/lEC 8802-12
1998
VGAnyLANTM
ATM LAN 25,60 Mb/s
ATM Forum af-phy-0040.000
1995
ATM-25/Category 3
ATM LAN 51,84 Mb/s
ATM Forum af-phy-00 18.000
1994
ATM-52/Category 3
ATM LAN 155,52 Mb/s
ATM Forum af-phy-0047.000
1995
ArM-155/Category 3
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
100-0hm Balanced Twisted-Pair Performance Category, continued
Table 1.16, continued
Applications supported using 100-ohm balanced twisted-pair cabling
Application
Specification Reference
Date
Additional Name
Class D (defined up to 100 MHz)
CSMA/CD lOOBASE-TX
lSO/IEC 8802-3
2000
Fast Ethernet
CSMA/CD I OOOBASE-T
ISO/IEC 8802-3
2000
Gigabit Ethernet
TP-PMD
ISO/JEC FCD9314-l0
2000
'I\visted-Pair Physical
Medium Dependent
ArM LAN 155.52 Mb/s
ATM Forum af-phy-0015.000
1994
AI'M-155/Category 5
2.5GBASE-T
IEEE 802.3bz
2016
2.5GBASE-T/Category 5e
Class E (defined up to 250 MHz)
AfM LAN 1.2 Gb/s
ArM Forum af-phy-0162.000
2001
ArM-1200/Category 6
CSMA/CD 1000BASE-TX
ANSIITIA/EIA-854
2001
Gigabit Ethernet/
Category 6
HDBASE-T
HDBASE-T Alliance
2010
HDBASE-T/Category 6
5GBASE-T
IEEE 802.3bz
2016
5GBASE-T/Category 6
Class E (defined up to 500 MHz)
CSMA/CD 10GBASE-T
ISO/IEC 8802-3
2006
10 Gigabit Ethernet
HDBaseT
HDBASE-T Alliance
2010
HDBASE-T/Category 6A
2005
Gigabit Ethernet/
Category 7
Class F (defined up to 600 MHz)
Fibre Channel
lOOOBASE-T
af-phy
ANSI
ATM
CSMA/CD
EIA
FCD
IEC
ISDN
ISLAN
ISO
ITU-T
MHz
PBX
TIA
TP-PMD
ISO/IEC 14165-114
= ATM Forum, physical layer specification
=American National Standards Institute
= Asynchronous transfer mode
=Carrier sense multiple access with collision detection
=Electronic Industries Alliance
=Final committee draft
=International Electrotechnical Commission
=Integrated services digital network
=Integrated services-LAN
=International Organization for Standardization
=International Telecommunications Union-Telecommunications Standardization Sector
= Megahertz
= Private branch exchange
=Telecommunications Industry Association
=Twisted-pair physical medium dependent
TDMM, 14th edition
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© 2020 IHCSI®
Chapter 1: Principles of Transmission
Media Selection
Table 1.17 shows various applications and the suggested media choice or choices.
Table 1.17
Media selection
Application
or Interface
Balanced
1\visted-Pair
Category 3
Balanced
1\visted-Pair
Category 6/6A
Analog
telephone set
X
X
X
Digital
telephone set
X
X
X
ANSI/TIA/F~IA-232-F
X
X
X
ANSI/TIA/EIA-422-B
X
X
X
ISDN
X
X
X
IEEE 802.3
lOBASE-'r
X
X
X
IEEE 802.5
1oken ring 16 Mb/s
See
Note I
X
X
ANSI X3.263 (TP-PMD)
X
X
IEEE 802.3
IOOBASE-TX
X
X
IEEE 802.3ab
IOOOBASE-T
X
X
IEEE 802.3 bz
2.5GBASE-T
X
IEEE 802.3 bz
5GBASE-T
X
IEEE 802.3an
lOGBASE-T
See
Note 3
ATM 25.6 Mb/s
X
X
X
AIM 12.96 Mb/s
X
X
X
ATM 51.8 Mb/s
X
X
X
X
X
ATM 155 Mb/s
© 2020 BICSI®
Balanced
1\visted-Pair
Category 5e
AT'M I Gb/s
X
ANSI/TIA/EIA-854 1 Gb/s
X
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Media Selection, continued
Table 1.17, continued
Media selection
Application
or Interface
Balanced
T\Yisted-Pair
Category 3
Balanced
Twisted-Pair
Category 5e
Balanced
1\visted-Pair
Category 6/6A
Video baseband
composite
X
X
X
Video baseband
component
X
X
X
See
Note 2
X
Video broadband
ANSI=
ATM =
EIA =
Gb/s =
IEEE=
ISDN =
TIA =
X=
American National Standards Institute
Asynchronous transfer mode
Electronic Industt·ies Alliance
Gigabit per second
Industry of Electrical and Electronics Engineers, Inc.®
Integrated services digital network
Telecommunications Industry Association
Media supported
NOTES: 1. This application is not normally recommended, but it may be used if the installed
cable meets qualification guidelines.
2. This application has a limited distance (e.g., less than;:::;] 00 m
[328ft]) or a limited number of broadband channels. Check the
manufacturer's recommendations.
3. This application has limited support over balanced UTP category 6.
Screened category 6 solutions will also support between ;:::;55 m (180ft) and
;:::;J 00 m (328 ft). Augmented category 6 (category 6/Class EA) will supp01i
the application for;:::;[OO m (328ft).
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Chapter 1: Principles of Transmission
Distances and Pair Requirements
Table 1.18 shows typical transmission distances and the number of balanced twisted-pairs
required for various data applications.
Table 1.18
Transmission, speed, distance, and pair requirements
Typical Distances Achieved
on 24AWG Balanced Twisted-Pair
ft
Balanced
Twisted-Pairs
1220
4000
1 to 2
19.2 kb/s
45
150
2 to 4
ANSI/TIA/EIA-422-B
Up to
10 Mb/s
15 to
1220*
50 to
4000*
2
ISDN-BRI
(2B+D)
160 kb/s
1000
3280
2 to 4
ISDN-PRI
(23B+D)
1.544 Mb/s
1500
4920
2
OS 1 rate
1.544 Mb/s
1500
4920
2
Token ring
(IEEE 802.5)
!6 Mb/s
100
328
2
10 Mb/s
100 Mb/s
100 Mb/s
1000 Mb/s
2.5 Gb/s
5 Gb/s
10 Gb/s
100
!00
100
100
100
100
55-100
328
328
328
328
328
328
180-328
2
2
4
4
4
4
4
Application
Line Rate
m
Integrated
voice/data
64 kb/s
ANSI/TIA/EIA-232-F
Ethernet
(IEEE 802.3)
lOBASE-T
100BASE-TX
100BASE-T4
lOOOBASE-T
2.5GBASE-T
5GBASE-T
lOGBASE-T
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Distances and Pair Requirements, continued
Table 1.18, continued
Transmission, speed, distance, and pair requirements
Typical Distances Achieved
on 24AWG Balanced 1Wisted-Pair
Line Rate
m
ft
Balanced
Twisted-Pairs
Category 3
Category 5
Category 5e
Category 6
12.96 Mb/s
200
320
320
365
656
1050
1050
1200
2
2
2
2
Category 3
25.6 Mb/s
100
328
2
Category 3
Category 5
Category 5e
Category 6
25.92 Mb/s
170
275
275
300
550
900
900
1000
2
2
2
2
Category 3
Category 5
Category 5e
Category 6
51.84 Mb/s
100
165
165
180
328
520
520
600
2
2
2
2
Category 5/5e
Category 6
155.52 Mb/s
100
110
328
361
2
2
Category 6
I Gb/s
100
328
4
Application
AT'M
ATM
ATM
ATM
ArM
ATM
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Distances and Pair Requirements, continued
Table 1.18, continued
Transmission, speed, distance, and pair requirements
Typical Distances Achieved
on 24 AWG Bahmccd 1\visted-Pair
Application
Balanced
Twisted-Pairs
Line Rate
m
ft
12.96 Mb/s
200
656
2
0--6 MHz
365
455
1200
1500
I ( +2 stereo)
I (+ 2 stereo)
0-30 MHz
100
328
150
492
3
3
60
100
70
200
328
230
1
1
100
328
ATM
Category 3
Video baseband
composite
Category 3
Category 5/5e/6
Video baseband
component
Category 3
Category 5/5e/6
Video broadband
Category 5e
Category 6
550 MHz
250 MHz
550 MHz
300 MHz
1
1
*The typical distance achieved depends on data rate-from <:::15.2 m (50ft) at 10 Mb/s to <:::1220 m (4003 ft) for data
rates of 90 kb/s or less.
ATM
ANSI
BRI
DS1
EIA
IEEE
ISDN
PRI
TIA
=
=
=
=
=
=
=
=
=
Asynchronous transfer mode
American National Standards Institute
Basic rate interface
Digital signal level 1
Electronic Industries Alliance
Industry of Electrical and Electronics Engineers, Inc. CR.J
Integrated services digital network
Primary rate interface
Telecommunications Industry Association
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Shared Sheath Applications and Compatibility
Installing additional cables is labor intensive and, therefore, costly. To make maximum
usc of the cabling resources, multi pair cable may be utilized to serve a number of different
applications.
Whenever possible, it is recommended to segregate different applications in separate
binder groups. Although PBX or key systems may coexist within the same cable, this is not
recommended for some systems because of crosstalk and impulse noise.
With regard to horizontal balanced twisted-pair cabling, it is generally recommended that
only one application be supported in a single cable sheath.
Examples of the restrictions on shared sheaths for specific applications using binder groups in
multipair cables having category 3 transmission characteristics include the following:
• No more than twelve lOBASE-T systems can share a common binder group.
• ANSI/TIA/EIA-232-F, lntetface Benveen Data Terminal Equipment and Data CircuitTerminating Equipment Employing Serial Binary Data Interchange, and ISDN applications
should be on separate binder groups.
• Signals from hosts with multiple controllers should not share the same binder group
(e.g., signals from the same controller can share the same binder group).
• Signals with significantly different power levels should not share the same binder group.
Generally, data transmission interfaces that are unbalanced with respect to ground cannot
be mixed with other systems. For example, the ANSI/TIA/EIA-232-F interface, when it is
extended using balanced twisted-pair cables, is incompatible with almost everything else.
However, the ANSf!TfA/EIA-232-F interface can be extended using limited distance modems
(ANSI/TIA/EIA-422-B, Electrical Characteristics ofBalanced Voltage Digitallnte~j'ace
Circuits). voice band modems, or optical fibers, which ease the compatibility constraints.
Although the ANSI/TIA/EIA-232-F standard limits the transmission distance to ;::o;45.8 m
(150ft) on metallic cable based on the 2500 pF limit, lCT distribution designers or installers
frequently attempt to extend this distance.
Backbone cabling systems may be called upon to carry both analog and digital signals from
more than one type of LAN, PBX, key system, and alarm system. Generally, all baseband
digital data transmission systems that operate at speeds of 64 kb/s or less are compatible
with analog and digital PBX and key system station circuits as long as they usc balanced
transmission schemes.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Media Conversion
Tenninal equipment that is equipped with a media interface other than balanced twisted-pair
can be easily adapted to balanced twisted-pair for signal transmission and can operate with
equivalent performance to that of coaxial, twinaxial, and dual coaxial.
Inmost cases, stricter distance limitations apply when media conversion is used. The
advantages of media conversion to balanced twisted-pair include the following:
• It can be a cost-effective solution.
• Moves can be simpler to implement.
• Less space in risers or conduits is required.
The three main categories of terminal interfaces are:
• Impedance-matching devices.
• Signal converters.
• Media filters.
Impedance-Matching Devices (Baluns)
Impedance-matching devices are commonly known as baluns. 'T'he term balun is taken
from the words balanced to unbalanced. Baluns are used to adapt the balanced impedance
of twisted-pairs to the unbalanced impedance of coaxial cables. Each media type requires
a specific type of balun to properly match its respective impedance. Baluns are required
wherever a transition is made from twisted-pair to coaxial or from coaxial to twisted-pair.
Baluns are additionally used to convert UTP cabling to coaxial cabling to support the
transmission of video over UTP. These baluns are normally located in the wall outlet for the
video service.
Signal Converters
Signal converters are electronic devices that receive one type of signal and output another
type of signal.
Some of the features of signal converters include:
• T,'iltering.
• Amplification.
The various types of signal converters include:
• Analog-to-digital converters (ADCs).
• Digital-to-analog converters (DACs ).
• Voltage converters.
• Frequency converters or translators that convert an input frequency to a different output
frequency.
Some of the advantages of signal converters are that they:
• Decrease the risk of transmission and EMI problems.
• Extend the unbalanced signal reach of a DTE.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Media Conversion, continued
Media Filters
Media filters may be required for the transmission of higher ti-equencies on balanced twistedpair. The filters eliminate unwanted frequencies affecting link performance that could radiate
from the balanced twisted-pair cable.
Transceivers
Transceivers arc radio frequency devices capable of sending and receiving radio frequencies.
These devices can be wired or wireless and arc used in many two-way telecommunications
devices. 'Transceiver devices arc also used in optical devices.
Conclusion
Knowledge ofthe design and performance of transmission systems is important to an ICT
distribution designer, even though the ICT distribution designer may never become involved
in any project requiring an in-depth knowledge of these parameters. Such familiarity will be
especially useful when determining the type of media to employ for a particular job.
Although the cabling transmission parameters are complex, the final result is that a
transmission circuit should be cost-effective, meet applicable standards, and have:
• A uniform characteristic impedance that is matched to the equipment.
• Low insertion loss/attenuation.
• High SNR and available bandwidth.
• Velocity of propagation that is relatively constant with frequency.
• High NEXT and FEXT loss between pairs.
• High NEXT and FEXT loss between pairs in adjacent cables and connectors.
• High noise immunity.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Power Over Ethernet (PoE)
PoE technology allows PoE powered devices to draw power from the same copper structured
cabling system used for LAN data transmission. 'This concept traditionally applied to wireless
APs, video surveillance cameras, and IP telephones, but since PoE power levels increased
the list of devices using PoE now includes kiosks, POS terminals, thin clients, digital signage
products, BAS, and LED lighting.
Combining power and data onto a single cable provides many benefits, including:
• Eliminating the need to provide ac electrical outlets at the same location.
• Faster installation times.
• Detecting loss of power to a device.
• In the event of a power failure, the network backup power system can service PoE devices
and systems, as well as other network devices.
IEEE 802.3, IEEE Standardfor Ethernet, defines four types of PoE.
• 802.3af defines a Type I maximum power output of 15.4 W from the PSE with up to
12.95 W delivered to the PD.
• 802.3at defines a Type 2 maximum power output of 30W from the PSE and up to 25.5 W
to the PD.
• 802.3bt is split into Type 3 and 4 where Type 3 provides up to 60 W from the PSE and 51 W
to the PD. Type 4 provides up to 90 W from the PSE and up to 73 W to the PD.
Power Source
Type l and 2 PSE may deliver de power over the two unused pairs in l OBASE-T or
I OOBASE-TX (e.g., pins 4-5 and pins 7-8). Alternatively, the standard allows for delivering
power over the signal pairs (e.g., pins 1-2 and pins 3-6) directly through switch ports. PDs
are designed to accept power over both options, whichever is being used by the PSE. The
maximum Type 1 PSE power output level is 15.4 W at 44 to 50 V (nominally 48 V).
Type 2, PoE+, PSE provides up to 25.5 W at 50 to 57 V.
Type 3 and 4 PSE deliver de power over all four pairs of a twisted-pair cable. The maximum
Type 3 source power output level is 60 W at 50 V. The maximum Type 4 source power
output level is up to 90-99 W at 52 V. A Type 3 or 4 PSE automatically negotiates the PD
power requirement and adjusts the power accordingly. Powering a Single-Signature PO or
Dual-Signature PO is supported by Type 3 and 4. Dual-Signature PDs deliver power to two
independent loads, each with different power requirements. A Dual-Signature PoE video
surveillance camera for example may use one pair to power the camera and the other pair to
power the heater.
Support for higher power with Type 3 and 4 opens more opportunities for the ICT industry.
It enables new markets and expands the PoE cabling to existing n1arkets that require higher
power devices such as connected LED lighting in intelligent buildings.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Power Over Ethernet (PoE), continued
link layer Discovery Protocol (llDP)
The Type 3 or 4 PSE power classification information exchanged during initial negotiation is
known as LLDP. LLDP requires bi-directional data packet exchange between the PSE and the
PD, is backwards compatible to Type 1/Type 2, and includes multiple PoE classes.
Only a PD connected directly to the PSE will negotiate and can be powered from the PSE. If
a second PD is daisy-chained from the PD that is connected to the PSE, the second PD cannot
be powered by the PSE.
The various PoE system classes range from 0 to 8. Type I and Type 2 include Class 0
through Class 4. Type 3 includes Class 5 up to 40 W and Class 6 up to 51 W at the PD.
Type 4 includes Class 7 up to 62 Wand Class 8 up to 73 W at the PD. There is some amount
of power that is budgeted for dissipation on the cables as heat in the worst case scenario of
;::;;) 00 m (328ft:) cables; therefore, the PSE output does not equal the PD input
(see Table 1.19).
Table 1.19
IEEE 802.3 PoE classes
PSE power
output (W)
PD maximum
input (\V)
15.4
12.95
4
3.84
2
7
6.49
3
15.4
12.95
4
30
25.5
5
45
40
6
60
51
7
75
62
8
90
73
Class
0
PD = Powered device
PSE = Power sourcing equipment
Not every port on a PoE switch may be fully powered. Each PD that requires power reduces
the allocation from the PSE power budget. Because PoE classes allow each PD to negotiate
unique power requirements, more devices can be powered by allowing the PSE power
management software to intelligently allocate only the required PD power on a per-port basis.
Reducing power delivered based on classes of PoE also reduces wasted power.
Jt is important to specify PSE equipment with a class that matches the PD equipment power.
If the power needed by the PD is not available, that PSE port is shut off.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Power Over Ethernet (PoE), continued
Power Sourcing Equipment (PSE)
Three practical power source equipment options for PoE are available:
• Endspan devices, a PoE switch can provide power to PD via the stmctured cabling system.
• Midspan devices, also known as power injectors, can be installed between a non-PoE switch
and the PoE device to add a de signal to the data signal, allowing the stmctured cabling
system to power up the PD.
• Local power sources, consisting of a power source plugged into an ac electrical outlet and
connected to the PD.
Figure 1.23 shows configuration examples for endspan and midspan power sources.
Figure 1.23
Typical configuration of endspan and midspan power source equipment
endspa:~~E switch
ac~······
I~i~ with PoE
P~:v~~:d
n
····"'?'
''-----------------------------------------~
== I
PSE
Switch
ac
~•••••• ••••~
BTP = Balanced twisted-pair
PoE = Power over Ethernet
PSE = Power sourcing equipment
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Optical Fiber
Overview
The two transmission media most often encountered in structured cabling systems are
balanced twisted-pair and optical fiber. Section 1 has discussed in detail the properties
of balanced twisted-pair cabling. In Section 2, the properties of optical fiber cabling are
addressed.
A simple model of a telecommunications system has three parts:
• Transmitter
• Receiver
• Medium
In an optical fiber system the medium is, of course, optical fiber. The transmitter and receiver
are designed to match with the properties of the medium. For an optical fiber system,
this means that the transmitter and receiver operate at optical frequencies. In this section,
the properties and performance of optical fiber transmitters, optical fiber receivers, and
optical fiber medium are addressed, in that order. At the end of the section, several system
applications are presented.
The optical fiber transmitter and receiver convert one type of energy to another type of
energy. An optical transmitter converts electrical signals to optical signals for transmission
over an optical fiber cable. At the receiver, the optical signals are converted back into
electrical signals. The use of optical transceivers, which combine the functions of an optical
transmitter and receiver, is common in the industry.
NOTE: Per applicable standards (e.g., ISO/IEC 11801-1 and TIA 568.3) OMl (62.5/125)
and OM2 (standard 50/125) are legacy. These MMF cables are not used for new
installations but are used for upgrading preexisting cabling systems.
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Chapter 1: Principles of Transmission
0
I fiber Transmitters
Overview
Almost all available optical fiber electronics contain an optical transmitter. This optical
transmitter consists of one of the following:
• LED
• VCSEL
• LD
The transmitter is an electronic device that:
• Receives a modulated electrical signal.
• Converts the modulated electrical signal into a modulated optical signal (usually digital).
• Launches the modulated optical signal into an optical fiber.
light-Source Characteristics that Influence Optical Fiber Selection
Some common characteristics of the light pulses emitted by an optical transmitter influence
optical fiber selection are the:
• Center wavelength.
• Spectral width.
• Emission pattern.
• Average power.
• Modulation frequency.
Center Wavelength
Any light source emits light within some range of wavelengths. Optical fiber transmitters
used with glass optical fibers normally emit light at or near one of the following four nominal
wavelengths, measured in nanometers:
• 850 nm
• 1300 nm
• 1310 11111
• 155011111
'I'his nominal value is called the center wavelength.
Although the periodicity of the EM radiation emitted by optical transmitters could be
specified using either frequency or wavelength, it is traditionally specified by wavelength.
Recall that frequency and wavelength are related by the formula v = f)c where vis the
velocity of propagation in the transmission medium.
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Chapter 1: Principles of Transmission
light-Source Characteristics that Influence Optical Fiber Selection, continued
Spectral Width
The total power emitted by a transmitter is distributed over a range of wavelengths
spread around a center wavelength. This range is the spectral width, typically specified in
nanometers. Spectral widths vary from narrow for lasers (several nanometers) to wide for
LEOs (from tens to hundreds of nanometers [see Figure 1.24]).
Figure 1.24
Spectral profile comparison of laser and LED
/Laser
>
4-1
{/)
c
(})
....,
c
,.....
LED~
1250
1300
1350
Wavelength (nm)
LED= Light-emitting diode
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Chapter 1: Principles of Transmission
light-Source Characteristics that Influence Optical Fiber Selection, continued
Spectral width is usually given as the range of wavelengths emitted with an intensity level
greater than or equal to one half of the peak intensity level, referred to as the FWHM spectral
width. See Figure 1.25.
Figure 1.25
Spectral width of an LED source showing full width half maximum
---,
Maximum
intensity
>-
~
Ul
c
t
...,Q)
c
H
One-half
maximum
intensity
Full width half maximum
spectral width
Wavelength (nm)
Wide spectral widths lead to increased dispersion of light pulses as the light pulses propagate
through an optical fiber.
Average Power
The average power of the transmitter is the mean level of power output of a given light source
during modulation.
Measured in dBm or m W, the average coupled power is usually specified for a particular:
• Optical fiber core size.
• Numerical aperature.
The more power a transmitter launches into an optical fiber, the more optical power is
available for the loss budget.
A mismatch of the numerical aperature and core size may cause a different level of power
launched into the optical fiber than the expected average power. This is because an LED
launches a large "spot" size of light. VCSELs and SWDM VCSELs launch a smaller spot size
of light, typically 25 11m. Therefore, the average power launched into a 50/125 ~tm fiber core
by these sources is the same as the expected average power.
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Chapter 1: Principles of Transmission
light-Source Characteristics that Influence Optical fiber Selection, continued
Figure 1.26 shows a comparison of the core size, numerical aperature, and LED.
Figure 1.26
Numerical aperture
NA = sin8
~Acceptance
cone
Comparison of Core Size, NA, and LED-Coupled Power
Fiber Size
(1-Jm)
0
0
50/125
62.5/125
Numerical Aperture
(NA)*
Relative Coupled Power
from 62.5/125 1-1m
0.20
-5.7 dB
0.275
0 dB
* Variations of 1% to 5% in NA specifications among different optical fiber and suppliers can result in
different measurement results.
LED= Light-emitting diode
NA = Numerical aperture
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Chapter 1: Principles of Transmission
light-Source Characteristics that Influence Optical fiber Selection, continued
Modulation frequency
The modulation frequency of a transmitter is the rate at which the transmission changes in
intensity. Typically, the transmitter is modulated by a string of bits that turn the transmitter's
light source on and off. LEOs have a relatively low modulation frequency and are limited to
data rates of 622 Mb/s and below. Lasers have a higher modulation tl·equency and can support
data rates in excess of 50 Gb/s.
Transmitter light Sources
The three major types of transmitter light sources are:
• LEOs.
• VCSELs.
• LOs.
light-Emitting Diode (LED)
The LED is a common and relatively inexpensive transmitter light source. Table 1.20
describes the characteristics of typical LED sources.
Table 1.20
Characteristics of typical LED sources
Item
Characteristics
Cost
Relatively inexpensive
Usc
Primarily used with multimode optical fiber
telecommunications systems
Center wavelength
• 800 to 900 nm
• 1250 to 1350 nm
Spectral width
Usually:
• 30 to 60 nm FWHM in the lower region (near 850 nm)
• Up to 150 nm FWHM in the higher region (near
1300 nm) because lower material dispersion LED
sources operating near 850 nm are typically more
economical. Data rates up to 100 Mb/s typically use
short wavelength LEOs; long wave length LEOs are for
data rates of 100 to 622 Mb/s.
Modulation frequency
• Most are under 200 MHz
• Can be as high as 600 MHz
Average launched
optical power level
--10 to -30 dBm into multimode fiber
FWHM = Full width half maximum
LED= Light-emitting diode
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Chapter 1: Principles of Transmission
Transmitter light Sources, continued
Short Wavelength Lasers
Table 1.21 describes the characteristics of typical short wavelength laser.
Table 1.21
Characteristics of typical short wavelength laser
Hem
Characteristic
Cost
Relatively inexpensive
Use
Primarily used with multimode optical fiber information
technology systems at the higher data rates from
200 Mb/s to I Gb/s. Principal application is Fibre Channel
Center wavelength
780 nm
Spectral width
Narrow compared with LEOs (4 nm)
Modulation frequency
Higher than LEOs (can exceed l Ghz), allowing
them to operate at higher data rates
Average launched
optical power level
+l to --8 decibels per mW (dBm)
LED = Light-emitting diode
Vertical Cavity Surface Emitting Laser (VCSEL)
VCSELs were introduced as a cost-effective multimode transmitter for Gigabit Ethernet and
Fibre Channel. They are also used for 10 Gigabit Ethernet and 8 Gb Fibre Channel and data
rates such as 40 Gb and more.
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Chapter 1: Principles of Transmission
Transmitter light Sources, continued
Although VCSELs have laser performance characteristics, they are easy to manufacture and
are priced less than LEDs by many manufacturers. Table 1.22 describes the characteristics of
typical VCSEL sources.
Table 1.22
Characteristics of typical VCSELs
Hem
Characteristics
Cost
Relatively inexpensive
Use
Used with multimode optical fiber information technology
systems at high data rates of 1 Gb/s and greater
Center wavelength
850 nm and 1300 nm
Spectral width
Very narrow (I to 6 nm) root mean square
Modulation frequency
Much higher than LEDs, allowing up to 56 GHz
Average launched
optical power level
-1 to -8 decibels per milliwatt into multi mode fiber
LED = light-emitting diode
NOTE: Unlike LEDs, VCSELs launch their full power into multimode optical fiber cabling.
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Chapter 1: Principles of Transmission
Transmitter light Sources, continued
laser Diodes ( lDs)
LOs (or simply lasers) are typically more expensive than LED and shoti wavelength laser
sources. Table 1.23 describes the characteristics of typical LD sources.
Table 1.23
Characteristics of typical LD sources
Item
Characteristics
Cost
More expensive than LED and VCSEL sources
Use
Used almost exclusively in singlemode optical fiber links
Some available systems use lasers with multimode optical fiber
to maximize the achievable system length.
Center wavelength
Center wavelengths of about:
131 0 nm are the most predominant.
1550 nm are becoming more popular for long-distance
communications in singlemode systems.
Spectral width
Narrow (usually l to 6 nm full width half maximum) compared
with LEDs
Modulation frequency
Faster than LEOs. Modulation frequencies exceeding 56 GHz
are achievable.
Average launched
optical power level
Higher than LEDs, with conunon values of +4 to -9 decibels
per milliwatt into singlemode optical fibers
WARNING: These power levels may present a safety hazard if
viewed directly.
LED= Light-emitting diode
VCSEL = Vertical cavity surface emitting laser
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Chapter 1: Principles of Transmission
Comparison of transmitters
Table 1.24 provides a summarized comparison of LED, short wavelength laser, VCSEL, and
LD.
Table 1.24
Comparison of transmitters
LED
VCSEL
Laser (LD)
Cost
Less expensive
Less expensive
More expensive
Primary optical
fiber type
Multimode
Multimode
Singlemode
Center wavelength
850 nm and
1300 nm
850 nm
1310 nm and
155011111
Spectral width
For 850,
30 to 60 11111
FWHM
1 to 6 nm
FWHM
l to 6 nm
FWHM
For 1300,up
to 150 nm
FWHM
Modulation frequency
Usually under
200 MHz
Up to 10 GHz
Can exceed
lOGHz
Average launched
optical power level
-10 to
-30 dBm
-1 to
---8dBm
+4 to
--9 dBm
FWHM = Full width half maximum
LED= Light-emitting diode
VCSEL =Vertical cavity surface emitting laser
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Chapter 1: Principles of Transmission
Optical Fiber Receivers
Overview
Almost all types of optical fiber receivers incorporate a photodctcctor to convert the incoming
optical signal to an electrical signal.
The receiver is selected to match the transmitter and the optical fiber.
Characteristic Parameters
The characteristic parameters of optical fiber receivers are the:
• Sensitivity.
• BER.
• Dynamic range.
Sensitivity and Bit Error Rate (BER)
Receiver sensitivity and BER are related:
• The sensitivity of a receiver specifics the minimum power level an incoming signal must
have to achieve an acceptable level ofpcrfonnancc, which is usually specified as a BER.
• BER is the fractional number of errors allowed to occur between the transmitter and
receiver. For example, a BER of 10-9 means one bit error for each one billion bits sent. (This
error rate is readily available in current systems.)
lfthe power of the incoming signal falls below the receiver sensitivity, the number of bit
errors increases beyond the maximum BER specified for that receiver.
If too little power is received at the detector, the results can be:
• A detected signal with high bit errors.
• No signal detection.
Dynamic Range
Too much received signal power can also compromise the receiver's operation.
If too much power is received at the detector, the results can be:
• Higher than acceptable BER.
• Possible physical damage to the receiver.
The dynamic range is the range of power that a receiver can process at a specified BER. This
is determined by the difference between the maximum power and the minimum power that
the receiver can process at a specified BER.
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Chapter 1: Principles of Transmission
0
I Fiber Medium
Optical fiber Core Size Selection Parameters
The key factors in determining which optical fiber to use in a given application are:
• Active equipment.
• Distance.
• Bandwidth (data rate).
Active Equipment
Before determining the core size of the optical fiber, certain considerations should be
evaluated that determine how cable and components are selected for an ICT link, segment, or
system.
While the order may occur differently, the elements that need to be considered are the same.
At the heart of the design is the application to be serviced. This determines what electronics
and passive equipment are available to support the application. This may be a new service or
an addition to existing equipment.
Existing equipment limits the choices because some of the system parameters and
specifications are already established. If there is no existing equipment, the system design is
more t-lexible. An important factor is the distance between the two end points of the system.
The characteristics of the optical fiber and the capability of the active equipment determine
how far apart the end points can be.
Optical fiber ICT links range from short links between active equipment and connections to
long telephone trunk lines. The end-to-end length of the longest link in the system and the
transmission data rate needed are major considerations in the selection of an optical fiber
type or size based on the active components. In some networks, there may be more than one
acceptable type of optical fiber because of the range of link lengths involved and the available
active equipment.
For example, a bank in Philadelphia may use a:
• Singlemode fiber optic network for MAN/WAN communications between its branch offices
and a main office in Baltimore.
• Multimode fiber optic network for LAN communications within its individual branch
offices.
Increasing the length of a link results in:
• An increase in the total attenuation of the signal from one end to another.
• Reduced system bandwidth because of dispersion.
• Signal distortion caused by the DMD phenomenon in multimode fiber.
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Chapter 1: Principles of Transmission
Active Equipment, continued
LEOs and VCSELs are typically associated with multimode optical fiber. A standard laser is
typically associated with singlemode optical fiber.
After determining which optical fiber to use based on the loss budget available and the type of
active equipment, the correct optical fiber cable can be assembled so that the system functions
correctly within the required parameters of all the components that make up the channel.
Transmission Media
There are five classes of multimode optical fiber cabling-OM 1, OM2, OM3, OM4, and
OMS. OMI and OM2 are legacy and not recognized for new installations. There are two
classes of optical singlemode (OS l a and OS2).
Table 1.25 shows the performance of optical fiber cable by type.
Table 1.25
Optical fiber cable performance by type
Classification
Optical Fiber Type
Performance
OMI
62.5/125 f.lm multimode
grandfathered
Minimum bandwidth of200 and
500 megahertz over 1 kilometer
(MHz•km) at 850 and 1300 nm,
respectively.
OM2
50/125 f.ll11 multimode
grandfathered
Minimum bandwidth of 500 and
500 MHz•km at 850 and 1300 nm,
respectively.
OM3
50/125 ~tm 850 nm laser
optimized multimode
Minimum bandwidth of2000 and
500 MHz•lon at 850 and 1300 nm,
respectively.
OM4
50/125 ~un 850 nm laser
optimized multimode
Minimum bandwidth of 4700 and
500 MHz•km at 850 and 1300 nm,
respectively.
OMS
50/125 f.lm 850, 880, 910,
940 nm lengths VCSEL
light for CWDM
Minimum bandwidth of 4700 and
500 Mhz • km at 850 and 1300 nm,
respectively.
OSla
Singlemode
Specified for 1310 and 1550 nm. At
1383 nm (water peak), attenuation
is reduced to 1 dB.
OS2
Singlemode
Low water-peak, suitable for coarse
wavelength division multiplexing
specified for 1310, 1383 and
1550 nm.
CWDM =Coarse wavelength division multiplexing
OM =Optical multimode
VCSEL =Vertical cavity surface emitting laser
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Chapter 1: Principles of Transmission
Bandwidth
Overview
Bandwidth is the information-carrying capacity of a system. The end-to-end bandwidth of a
system is related to the respective bandwidths of its component parts. Figure 1.27 represents
an example of system bandwidth versus distance.
For an optical fiber system, the essential determinants of the end-to-end bandwidth are the:
• Transmitter.
• Optical fiber.
Installation techniques cannot adversely affect optical fiber bandwidth (multimode) and
dispersion (singlemode). Therefore, field measurements are not required.
Figure 1.27
System bandwidth versus distance example
1100 . ..----------------------------------------------------------,
1000
--=Modal
- - =Modal and chromatic
900
,-..,
N
800
I
2.:
..c
.....,
u
·~
700
600
u
c
ru
.0
E
Q)
.....,
500
400
V1
>{/)
300
200
100
0.1
0.4
0.8
1.2
1.6
2
2.4
System length (km)
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Chapter 1: Principles of Transmission
Transmitters and Rise Time
Transmitters have bandwidth limitations because they take time to change from a low-power
state (logical 0) to a high-power state (logical l ). This period is called the rise time.
Rise time is usually measured from 10 percent to 90 percent power level. In simplified
discussions, the rise time is assumed to be zero. At high data rates, the rise time becomes
significant.
Figure 1.28 illustrates how transmitter rise time limits the maximum data rate of a system.
The illustration shows the difference between the simplified logical depiction of a bit stream
and actual performance of an optical transmitter.
• fn Area A, the transmitter has a real rise time that has no impact on the signal.
• Areas B and C show how the signal becomes distorted as the data rate is doubled and then
doubled again.
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Chapter 1: Principles of Transmission
Transmitters and Rise Time, continued
Figure 1.28
Pulse distortion because of rise time and data rate
_j___
0
t
1
1
1
0
0
Logical
L
(A)
GJ
:::
0
Typical bit stream
CL
··········································· ...... Actual
----Time--..
011010
t
..................................................................... Logical
L
GJ
(B)
Data rate doubled
$
0
CL
.............................................................................................. Actual
---Time--..
011 01 0
t
L
GJ
$
(C)
rul· .
Data rate quadrupled
0
CL
......................................... Logical
~
····•·•······•···············•···•· ··············
····························Actual
---Time__..
NOTE: As the data rate is doubled and then doubled again, the effect of a non-perfect actual
pulse results in more and more distmiion.
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Chapter 1: Principles of Transmission
Optical Fibers
Optical fibers have bandwidth limitations because of dispersion. Dispersion causes a light
pulse to broaden in duration as it travels through the optical fiber.
Singlemode System
Instead ofbandwidth, the maximum pulse distortion is frequently used to define system
capacity in singlemode systems. Pulse distortion is a function of transmitter spectral width
and the optical fiber construction and length.
NOTE: Singlemode dispersion is seldom a concern in premises applications.
The maximum optical fiber dispersion is usually expressed in picoseconds of pulse
broadening per the product of nanometers of transmitter spectral width and system length
(psec/nm-km).
NOTE: To calculate link dispersion, multiply the specified optical fiber dispersion value at
the center wavelength of the light source by the source spectral width and the length
of the optical fiber link. Compare this figure with the maximum allowable dispersion
stated by the manufacturer for the receiver in question.
Dispersion in singlemode systems is a function of wavelength. 1t is important that the
optical fiber dispersion specification coincides with the operating wavelength range of the
transmitter.
Multimode System
Calculating and predicting the bandwidth requirements of a multi mode system is more
complex than determining the dispersion of a singlemode system. It consists of combining the
effects of all three of the following:
• Transmitter rise time
• Optical fiber modal dispersion
• Chromatic dispersion
NOTE: This involves complex assumptions and calculations that are beyond the scope of
this publication. The application standards or OEM typically determine the minimum
optical fiber bandwidth necessary to support a given system.
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Chapter 1: Principles of Transmission
Chromatic and Modal Dispersion in Multimode Systems
The bandwidth of a multimode system is a function of chromatic dispersion and modal
dispersion as well as length.
Chromatic Dispersion
The LED and VCSEL sources frequently used with multimode systems have broader spectral
widths than singlemode laser sources. 'T'his results in chromatic dispersion. Chromatic
dispersion occurs when the wider range of wavelengths in each pulse travels at a wider range
of individual speeds. This causes the duration of a pulse to increase with distance.
The amount of chromatic dispersion that occurs depends partly on the center wavelength of
the link. Most glass optical fibers have minimal chromatic dispersion characteristics near
1300 nm.
Modal Dispersion
The various modes of light propagation in a multimode optical fiber follow different paths
through the core of the optical fiber. These individual paths have different lengths. The light
that travels along the shortest path (lowest order mode) arrives at the end of the optical fiber
before the light that travels along the longer paths (higher order modes). A pulse oflight,
which consists of hundreds of modes in a multimode optical fiber, broadens in time as it
travels through the optical fiber. T'his type of dispersion is called modal dispersion.
Measurement and Specification of Multimode Systems
Optical fiber suppliers usually measure bandwidth using a narrow laser source on a
fixed length of optical fiber because of the variation of chromatic dispersion with source
characteristics (e.g., center wavelength, spectral width) and optical fiber length. The
bandwidth value stated by the supplier only represents the effect of modal dispersion because
the spectral width of a typical laser source is usually so small it makes chromatic dispersion
negligible.
Because the bandwidth reported by the optical fiber and cable supplier is the result of a
measurement made with an LD source, this measurement is not readily applied to LED
system design.
The modal bandwidth (e.g., usually called the optical fiber bandwidth by manufacturers and
suppliers) is commonly expressed as a frequency-distance product (e.g., MHz/km). This
means a given optical fiber can support higher transmission rates over a shorter distance than
it can over a long distance.
For example, a system requiring 90 MHz of end-to-end bandwidth requires a higher grade
of optical fiber for a ;:::;2 km (1.2 mi) link than for a;:::;) km (0.6 mi) link. For links of several
hundred meters/feet or less, optical fiber bandwidth often is not a consideration.
© 2020 BICSI®
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Chapter 1: Principles of Transmission
Measurement and Specification of Multimode Systems, continued
Calculation
Much experimentation has been conducted to characterize the relationship between the:
• Modal component of multimode optical fiber bandwidth.
• System bandwidth of a complete optical fiber channel.
Several methods are proposed for approximating this relationship--all are mathematically
cumbersome. They take into account the:
• Dispersion behavior of the optical fiber.
• Spectral characteristics of the transmitter.
Figure 1.29 shows an example of a conservative algorithm used to generate a curve of system
length versus system bandwidth for a typical 62.51125 )-UTI multimode optical fiber and a
specific LED transmitter. If only the bandwidth-distance product from the manutltcturer's
specification were used, the curve would predict a longer achievable system length. This
demonstrates the dangerous errors that result from oversimplification of a bandwidth
calculation.
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Chapter 1: Principles of Transmission
Measurement and Specification of Multimode Systems, continued
Figure 1.29
Link bandwidth at 1300 nm using 62.5/125 micrometer multimode optical fiber
500
450
Transmitter characteristics:
• Optical fiber = 62.5 IJm
Modal bandwidth = 500 MHz•km
• Transmitter
Ac
1300 nm
l:l A = 140 nm
400-
N'
350
I
2:
u
c
(])
I
300
0
.....,
I
u
c
(])
..c:
.....,
u
~
250
System prediction
incorrectly based on
modal bandwidth only
·~
u
c
l1l
.0
:::1.
200
c
:J
150
100
50
0
0
1
2
3
4
5
6
Distance (km)
Determining the required optical fiber bandwidth is best left to the electronics, cable, or
optical fiber manufacturer.
© 2020 BICSI®
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Chapter 1: Principles of Transmission
Classification of Optical fiber
The two major classifications of optical fiber are multimode and singlemode.
Multi mode optical fiber is best suited for premises applications where links are less than:
• :::::.:2000 m (6562 ft) for data rates of 155 Mb/s or less.
• :::::550 m ( 1804 ft) for data rates of 1 Gb/s or less.
• :::::300m (984 it) for data rates of 10 Gb/s or less.
• :::::.:100 m (328 ft) for data rates of I 00 Gb/s or 40 Gb/s or less.
Multimode optical fiber's higher numerical aperature allows the use of relatively inexpensive
LED and VCSEL transmitters. These are more than adequate for short-distance applications.
NOTE: See Multimode Optical Fiber in this chapter for typical characteristics ofmultimode
optical fiber.
Singlemode optical fiber is best suited for:
• Bandwidth requirements exceeding multimocle's capability.
• Distances exceeding multilnocle's capability.
• When the application requires singlemode.
NOTE: See Singlemode Optical Fiber in this chapter for typical characteristics of singlemode
optical fiber.
Table 1.26 summarizes the comparisons between the two multimode types and singlemode
optical fibers.
Table 1.26
Summarized comparison of core sizes of multimode and singlemode optical fiber cable
Multimode
Siuglemode
Item
OMt
grandfatbered
OM2
grandfathered
OM3/4
OMS
DispersionUnshifted
Attenuation
Low
Low
Low
Low
Lowest
Bandwidth
Moderate
Higher
Higher
Higher
Very high
Numerical aperture
Midrange
Smaller
Smaller
Smaller
Very small
Optical fiber outside
diameter
125
125~-tm
I 25
Wavelength
850 nm and
130011111
850 nm and
1300 nm
850 nm and
1300 nm
TDMM, 14th edition
~un
1-98
~tm
125
~un
850/880/910
940 nm and
130011111
125 !-Ll11
1310 nm and
1550 nm
© 2020 BICSI®
Chapter 1: Principles of Transmission
Multimode Optical Fiber
The typical characteristics of multimode optical fiber are shown in Table 1.27.
Table 1.27
Typical characteristics of multimode optical fiber
Item
Characteristic
Optical fiber size
The two popular sizes of multimode optical fibers were:
• 62.5/125 pm .
• 50/125 ~ll11.
But now only OMJ/4/5 can be chosen in greenfield.
See Table 1.28 and 1.29 for more information.
NOl'E: Multimode optical fibers are frequently referred to by
the core and cladding diameter in micrometers (see
Figure 1.30). For example, a multimode optical fiber with
a core diameter of 62.5 pm and a cladding diameter of
125 ~un is typically designated as a 62.5/125 ~Lm optical
fiber.
Cost
While the multimode optical fiber cable is more expensive than
singlemode, the installed system is less expensive than singlemode
systems because of the more cost-effective electronics and
connectors.
Distance
Used mostly for information technology systems links less than
;:::;2 km (1.2 mi) long.
Capacity
• Data rates of 155 Mb/s are common for campus links of less than
;:::;2 km ( l.2 mi).
• Data rates of I Gb/s are common for building or campus
backbones ofless than ;:::;5 50 m ( 1804 ft).
• Data rates of 10 Gb/s are f(w building backbones less than
;:::;JQO m (984 ft).
Operating
wavelength
Operates at:
• 850 nm (first window-LED or vertical cavity surface emitting
laser).
• 1300 nm (second window--LED or laser diode).
System type
Used for voice, data, security, and closed-circuit video systems.
LED = Light-emitting diode
© 2020 BICSI®
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TDMM, 14th edition
Chapter 1: Principles of Transmission
Multimode Optical fiber, continued
Figure 1.30
Core and coating
Coating/
buffer
Cladding
Table 1.28 shows the characteristics of 50/125
Table 1.28
Characteristics of 50/125
[.1111
~un
multi mode optical fiber.
multimode optical fiber
Item
Characteristic
Attenuation
Low attenuation at 850 nm and 1300 nm wavelength regions.
Bandwidth
Higher than that of 62.5/125
Numerical
Lower NA and smaller core size results in Jess coupling
power compared with that of 62.5/125 fiber for LED systems
aperture (NA). Laser systems (VCSELs) are not affected.
Mechanical
Compatible with all 62.5/125 Jlm multimode and singlemode
optical fiber connector patis because of the common cladding
diameter.
~tm
multimode fiber.
LED= Light-emitting diode
NA = Numerical aperture
VCSEL = Vertical cavity surface emitting laser
As more strict tolerance is required for ferrules used with SM fiber, termination of multimode
connector onto singlemode fiber is not recommended. The opposite combination does not
adversely affect the performance.
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Chapter 1: Principles of Transmission
Multimode Optical Fiber, continued
Table 1.29 shows the characteristics of 62.5/125
~un
multimode optical fiber.
Table 1.29
Characteristics of 62.5/125 1Jm multimode optical fiber
Item
Characteristic
Attenuation
Slightly higher attenuation than 50/125
Bandwidth
Moderate bandwidth that accommodates most data applications
Numerical
Higher NAthan 50/125 ~tm optical fiber, allowing more power
apetiure (NA) coupled from an LED into the optical fiber.
Compatibility
Compatible with all 50/125 J.ll11 multimode and singlemode optical
fiber connector parts because of the common cladding diameter.
~un
optical fiber.
LED = Light-emitting diode
NA = Numerical aperture
As more strict tolerance is required for ferrules used with SM fiber, termination of multi mode
connector onto singlemode fiber is not recommended. The opposite combination does not
adversely affect the performance.
Wavelength Windows
Optical fibers do not transmit all wavelengths of light with the same efficiency. The
attenuation oflight signals is higher for visible light (wavelengths of 400 nm to 700 nm) than
for light in the near infrared region (wavelengths of700 nm to 1600 nm).
Within this near infrared region, there are wavelength bands of decreased transmission
efficiency. This leaves only several wavelengths that optical fibers can operate with low
loss. These wavelength areas that are most suitable for optical communications are called
windows. The most commonly used windows are found near 850 nm, 1300 nm, and 1550 nm.
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Chapter 1: Principles of Transmission
Singlemode Optical fiber
Singlemode optical fiber is similar to multimode optical fiber in physical appearance and
composition, but it has performance characteristics that differ by orders of magnitude from
those ofmultimode optical fibers (see Table 1.30).
Table 1.30
Typical characteristics of singlemode optical fiber
Item
Characteristic
Distance
Used by service providers (e.g., telephone, CATV). Unrepeated
spans in excess of~so km (50 mi) are achievable with state-ofthe-art equipment.
Capacity
Data rate transmission in excess of 40 Gb/s range is common.
System performance
• Very high bandwidth
• Very low attenuation
• Good for telephony and CATV applications
• Ideal for local applications having links over ~2 km ( 1.2 mi)
long
• Satisfies high bandwidth needs in backbone applications up to
~so km (50 mi)
Optical fiber
• Core diameter: between 8 and 9 11m characteristic
• Cladding diameter: 125 ~un
• Attenuation: 0.3 to 1.0 dB/km at 1310 nm, 1383 nm, and
1550 nm
• Bandwidth: greater than 20 GHz
• Numerical aperture: Because the NA is very small, the optical
fibers are used almost exclusively with laser sources that can
concentrate more power into a smaller launch area.
Cost
Less expensive than multimode optical fiber, but the higher cost
of singlemode transmission equipment usually means a higher
system cost in short length (premises) systems.
Operating wavelength
1310nmto 1550nm
CATV== Community antenna television
NA = Numerical aperture
NOTE: For singlemode optical fiber cable, the following maximum attenuation values are
generally specified:
• Outside cable---0.4 dB/km at 1310 nm, 1383 nm, and 1550 nm
•Inside cable-1 dB/km at 1310 nm, 1383 nm, and 155011111
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Chapter 1: Principles of Transmission
Optical Fiber Applications Support Information
Overview
This section provides an overview regarding applications support for many of the available
optical fiber LAN applications across the optical fiber media types. This information allows
the user to easily access enough basic information to make informed decisions about optical
media choices and system design.
With a predetermined knowledge ofthe required distances, an idea of the applications support
required and the cabling system design, the ICT distribution designer can determine the
media most appropriate for the situation.
Three primary factors must be considered in optical fiber selection and system design:
• Maximum supportable distance
• Maximum channel attenuation
• Application requirements
The first factor is maximum supportable distance based on bandwidth, transmitter and
receiver specifications, propagation delay, jitter, and numerous other factors. Maximum
supportable distance is established by the application standards.
The second factor is maximum channel attenuation, which is established by the difference
between the minimum transmitter output power coupled into the optical fiber and the receiver
sensitivity, less any power penalties established. The channel attenuation can be affected
by the system design (e.g., number of connections and/or splices, length, wavelength of
operation, loss values of components).
The third factor is application requirements, which is that end devices may require a specific
type of interface (e.g., singlemode).
Supportable Distances and Channel Attenuation
For existing systems, measure the channel attenuation. For new installations, use the
equations below, which are based on the minimum component specifications, to verify the
system design:
• Channel attenuation < Maximum channel attenuation
• Channel attenuation = Cable attenuation + connector attenuation + splice attenuation
• Channel attenuation= [Cable attenuation coefficient ( dB/km) x length (km)] + [#connector
pairs x 0.75 dB]+[# of splices x 0.3 dB]
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Chapter 1: Principles of Transmission
Supportable Distances and Channel Attenuation, continued
Therefore, to determine maximum length for a particular system design, the resulting
equation is:
Maximum length=
lMaximum channd attenuation- [IJ connector pairs x 0.75 dB]-[# splices x 0.3 dB])
Cable attenuation coefti.cient
The maximum cable attenuation coefti.cients are listed in Table 1.31.
NOTE: The maximum supportable distances and maximum channel attenuation listed
apply to the specific assumptions and constraints provided in the notes. Different
assumptions or constraints may change the maximum supportable distance and
maximum channel attenuation.
Table 1.31
Maximum cable attenuation coefficient
Optical Fiber
Cable Type
Wavelength
(mn)
Maximum
Attenuation
62.5/125 fllTI multimode
grand fathered
850
1300
3.5 dB/km
1.5 dB/km
50/125 fll11 multimode
grandfathered
850
1300
3.5 dB/km
1.5 dB/km
OM3/4
850
3.0 dB/km
OMS
850
3.0 dB/km
Singlemode
inside plant
cable
1310
1383
1550
l.O dB/km
1.0 dB/km
1.0 dB/km
Singlemode
outside plant
cable
1310
1383
1550
0.4 dB/km
0.4 dB/km
0.4 dB/km
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Chapter 1: Principles of Transmission
Verifying Optical fiber Performance and Electronics
Compatibility
Overview
This section is designed to provide an understanding of the relationship of the link to the
requirements of the electronics (transmitter and receiver). However, it is more critical to
ensure that the installed link meets the requirements of a generic cabling system, independent
of a specific application or electronic product.
Standards have been developed for generic cabling systems, both for multimode and single
mode systems, and for horizontal and backbone cabling. These requirements are based on
long-standing and field-proven test procedures, allowing both the end user and contractor to
certify the installation.
It is necessary to verify that the overall system will work properly whenever new components
are installed to reconfigure an existing system.
This is true whether the changes involve a new:
• Optical fiber cabling system for active components that have already been chosen.
• Active component system retrofitted to previously installed optical fiber cabling.
This verification is a repetitious process. Decisions regarding route, electronics, wavelength,
and system configuration are all interrelated. Often a trade-off analysis-varying one or more
of these parameters-is necessary.
Industry standardization is making verification easier. More manufacturers have developed
multimode LAN systems, which operate over multimode optical fiber. However, it is still
important that the ICT distribution designer or end user understand some of the fundamental
concepts and calculations necessary to verify that a system will work properly.
For short or basic systems, performance requirements have often already been considered by
the manufacturer and translated into system specifications for the:
• Optical cable lengths.
• Number of splices and connectors.
• Optical cable performance.
For longer or complex applications, it is generally recommended that the fCT distribution
designer analyze the proposed system.
Key Parameters
The two key parameters in optical fiber cabling performance that must be verified for
compatibility with the proposed electronics are:
• Bandwidth.
• Attenuation.
It is important to consider how specific grades of optical fiber affect system performance.
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Chapter 1: Principles of Transmission
Verification Theory and Methodology
The theory and methodology used to verify appropriate optical fiber performance are the
same for both singlemode and multimode optical fibers at any wavelength.
IMPORTANT: The specifications used for each of the components (e.g., transmitter,
receiver, optical fiber, connectors) must correspond to the optical fiber type
and wavelength.
For example, if designing a sing! em ode system to operate at I 310 nm, the
attenuation specified for a 50/125 ~un multimode connector cannot be used,
nor can the transmitter average power from an 850 nm LED source specified
for 50/125 ~tm optical fiber. Only the singlemode optical fiber specifications
for 1310 nm and connector loss specification for singlemode optical fiber can
be used.
Additionally, any transition from 50/125 ~m optical fiber (or a transmitter
source specified for 50/ I 25 ~un optical fiber) into 62.5 ~tm fiber for LE.:D
systems will have to take into account the attenuation at that junction (see
Table 1.32).
To increase testing accuracy for optical fiber link and channel loss measurements, it is
recommended to usc an LED light source with an EF mode conditioner to control the
near field at the output of the launching test cord. The EF test method is specified in
ANSf/TlA-526-14-C and IEC 61280-4-1.
Table 1.32
Mismatch of core size and power loss
0
0
0
0
50 fJm
(NA = 0.20)
62.5 fJm
(NA = 0.275)
50 fJm (NA = 0.20)
0.00
-5.7 dB
62.5 fJm (NA = 0.275)
0.00
0.00
NA = Numerical aperture
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Chapter 1: Principles of Transmission
Verification Theory and Methodology, continued
NOTE: Total loss= Total loss using OFL launch= Loss (numerical aperature)+ Loss (dia)
Loss (numerical aperature)= 1Olog 10 (0.20/0.275) 2 = -2.8 dB
Loss (dia) = 10log 10 (50/62.5) 2 = -2.9 dB
For telecommunications networks that have more than one optical fiber link, the ICT
distribution designer may:
• Choose the longest, most complex link to verify system performance and select that optical
fiber grade for the entire network.
• Select a specific optical fiber grade for each individual link. This is generally unnecessary
and is not recommended.
Bandwidth
The bandwidth for an optical fiber cannot be tested or validated in the field. Validation of
the bandwidth can only be through manufacturer's specification and quality checking of the
product specification sheets with the installed components. Specifically, for laser-optimized
50/125 ~un, OM3, OM4, and OMS optical fiber, the bandwidth performance for each glass
element of the end-to-end optical fiber channel, cable, cords, and pigtails should always be of
the same specification and preferably from the same manufacturing source and type.
When choosing the fiber type, it is important to know the applications that are to be supported
by the optical fiber channels and the applications bandwidth requirements for each of the
optical fiber types being considered. High-speed LAN applications (e.g., 10 Gigabit Ethernet,
40 Gigabit Ethernet) require the use of a VCSEL to deliver the light source. Because
a VCSEL illuminates a smaller number of modes in the optical fiber than an LED, the
bandwidth statement for these laser-optimized optical fiber are higher than for the LED.
Most optical fibers that are suitable for medium distance delivery of high-speed applications
have two bandwidth statements in the 850 nm window-one for an LED source OFL and one
for the VCSEL EMB.
Attenuation
The maximum permissible end-to-end system attenuation in a given link is determined by the
average transmitter power and the receiver sensitivity. To analyze a system's attenuation and
determine whether the proposed electronics will operate over the cable plant, follow the nine
steps shown in Table-1.33 and then check the minimum system loss (see Checking Minimum
System Loss in this chapter). The nine steps are explained in detail on the pages following
Table 1.33.
NOTE: Be sure the test setup simulates the actual system. (Select the required minimum
transmission-rate-capable transmitter and receiver and use the jumpers or at least
include their losses in final calculations.)
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Chapter 1: Principles of Transmission
Attenuation, continued
Table 1.33
Calculating optical Aber performance
Objective
Step
A. Calculate the
link loss budget
B. Calculate the
passive cable
system attenuation
loss
Calculate the system gain.
2
Determine the power penalties.
3
Calculate the link loss budget by subtracting the
power penalties from the system gain.
4
Calculate the optical fiber loss.
5
Calculate the connector loss.
6
Calculate the splice loss.
7
Calculate other component losses (e.g., bypassswitches, couplers, splitters).
Calculate the total passive cable system attenuation
by adding the results of Steps 4-7.
8
C. Verify
performance
TDMM, 14th edition
Calculation
9
Subtract the passive cable system attenuation (result
of Step 8) from the link loss budget (result of
Step 3).
The result is the system performance margin. If this
result is a negative number, the system will not
operate.
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Chapter 1: Principles of Transmission
Attenuation, continued
Example 1.1 illustrates how to calculate the system performance margin to verify adequate
power. Detailed information is provided on the following pages.
Example 1.1
Optical fiber performance calculations example
A.
Calculating the Link Loss Budget
Example manufacturer's
System Wavelength
1310 nm
electronic specifications
Optical fiber type
Singlemode
Average transmitter output
-3.0 dBm
Receiver sensitivity (10· 12 BER)
-19.0 dBm
16.0 dB
Receiver dynamic range
1. Calculate system gain
-
Average transmitter power
-
Receiver sensitivity
-(-19.0 dBm)
0.5
System gain
19.5 dB
3.0 dB
Operating margin (none stated)
2. Determine power penalties
+
dB
Receiver power penalties
+
0.0 dB
+
0.6 dB
(none stated)
+
Repair margin (2 fusion splices)
at 0.3 dB each)
3.6 dB
Total power penalties
System gain
3. Calculate link loss budget
-
B.
Power penalties
19.5 dB
3.6 dB
Total link loss budget
15.9 dB
Calculating the Passive Cable System Attenuation
Cable distance
4. Calculate optical fiber loss
at operating wavelength
X
Individual optical fiber loss
X
Total optical fiber loss
transmitter and receiver connectors)
0.6 dB
0.75 dB
Connector pair loss
5. Calculate connector loss (exclude
1.5 km
0.4 dB/km
X
Number of connector pairs
=
Total connector loss
X
4
·--~-~--~·
6. Calculate optical splice loss
3.0 dB
Individual splice loss
0.3 dB
3
X
Number of splices
=
Total splice loss
0.9 dB
Total components (none)
0.0 dB
X
··----··-··--·----·-··--
7. Calculate other component losses
8. Calculate total passive
cable system attenuation
C.
Total optical fiber loss
+ Total connector loss
+ Total splice loss
+ Total components
=
Total system attenuation
-
Passive cable system attenuation
0.6 dB
+
+
+
3.0 dB
0.9 dB
0.0 dB
--
4.5 dB
Verifying Performance
9. Calculate system performance
margin to verify adequate power
Link loss budget
15.9 dB
4.5 dB
~~~--~~~~~~----------~-------~~~~~-
System performance margin
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Chapter 1: Principles of Transmission
Attenuation, continued
A. Calculating the link loss Budget
The link loss budget is the maximum allowable loss for the end-to-end cable system. To
calculate the link loss budget, calculate the system gain and power penalties:
• System gain is the difference between the transmitter average power and the receiver
sensitivity.
• Power penalties are factors that adjust the system gain, including the operating margin,
receiver power penalty, and repair margin.
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Chapter 1: Principles of Transmission
Attenuation, continued
Table 1.34 explains how to calculate the system gain, power penalties, and link loss budget.
NOTE: For information on link loss budget calculations by the manufacturer, see the footnote
at the end of Table 1.34.
Table 1.34
System gain, power penalties, and link loss budget calculations
To Calculate the ...
You Must ...
System gain
Subtract the receiver sensitivity (in dBm) from the transmitter average power
(in dBm). This gives the maximum allowable loss (in dB) between the transmitter
and receiver for the BER specified for the receiver.
NOTE: If the transmitter power is not based on the optical flber type of the
system, it can be adjusted using the information in Table 1.31.
Power penalties
Add the loss values for the:
• Operating margin*-This loss accounts for:
-Variations in the transmitter center wavelength.
--Changes in the transmitter average power and receiver sensitivity that result
from age.
-Variations in the component temperature within the operating range of the
system. If the system manufacturer does not specify the operating margin, use
value of:
• 2 dB for LEDs.
• 3 dB for lasers.
• Receiver power penalty*-Some manufacturers may specify other power
penalties (dispersion, jitter, bandwidth, or clock recovery) that must be
subtracted from the system gain. If these are provided, they must be subtracted
from the available system gain.
• Repair margin*-Ifthe cable is located where it could be cut or damaged by
accident, allow sufficient loss margin in the design to accommodate at least two
repair splices. lfthe cable is in a high-risk area or reroutings are anticipated, the
lCT distribution designer may decide to allow for more than two splices.
Link loss budget*
Subtract the total value (in dB) for all of the power penalties from the system
gain. The result is the link loss budget.
* In some cases, the electronics manufacturer will have already calculated the link loss budget. In these cases, it is
usually safe to assume the operating margin (e.g., transmitter aging) and receiver power penalties have been included
in the manufacturer's calculations. However, the repair margin is usually not included in a manufacturer's link loss
budget calculations, unless the product documentation specifically states a repair margin. When a repair margin is not
stated by the manufacturer, the ICT distribution designer must subtract it from the system gain to determine the link
loss budget.
BER = Bit error rate
LED = Light-emitting diode
ICT = Information and communications technology
© 2020 BICSI®
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Chapter 1: Principles of Transmission
Attenuation, continued
B. Calculating the Passive Cable System Attenuation
To calculate the passive cable system attenuation, total the values for the:
• Optical fiber loss.
• Connector loss.
• Splice loss.
• Other component losses.
NOTE: When working with existing cable plant, passive cable system attenuation can be
measured directly. Table 1.35 explains how to calculate each of these losses.
Table 1.35
Calculating losses
To Calculate the ...
You Must...
Optical fiber loss
Multiply the length of the proposed link by the normalized cable
attenuation (dB/km) for the optical fiber at the operating system
wavelength.
NOTE: Temperature may affect the loss of the optical fiber cable.
See Effects of Temperature on Optical Fiber Loss.
Connector loss
Add the individual attenuation values (in dB) for every connector
pair along the optical fiber route, from transmitter to receiver,
excluding the transmitter and receiver connectors (see Connector
Loss Values).
NOTE: A connector as described here refers to a mated connector
pair in a channel where all the connectors are the same
type. The channel may have two, three, or four
connectors. For channels with more than two connectors,
a lower loss connector is required to meet the loss budget.
Splice loss
Add the individual local attenuation values (in dB) for every
splice along the optical fiber route, from transmitter to receiver
(see Splice Loss Values).
Other component
Add the attenuation values of any other components that
contribute to losses in the optical fiber route, from transmitter to
rece1ver.
Total loss
Add the values for each of these losses to get the total passive
cable system attenuation.
NOT'E: Example calculations tor the passive cable system attenuation and its four
components are shown in Example 1.1.
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© 2020 BICSI®
Chapter 1: Principles of Transmission
Attenuation, continued
Effects of Temperature on Optical Fiber loss
Temperature changes may affect the Joss of optical fiber cable. Loss variations because
of temperature changes can sometimes be as high as 0.2 dB/km. Some manufacturers'
specifications indicate the cable's loss only at room temperature rather than throughout the
operating temperature range.
Add an additional margin (in dB/km) to the normalized optical fiber attenuation value
when calculating the optical fiber link loss, as explained earlier in this section, if the cable's
specifications are:
• For room temperature only.
• Based on an average of several optical fibers.
Connector Loss Values
When designing links with:
• Zero to four connector pairs, use the maximum value.
• Five or more connector pairs, use the typical value.
NOTE: The maximum connection loss of0.75 dB is recommended. SFF connectors should
meet or exceed these attenuation requirements. Consult the connector manufacturer
to provide the average and maximum loss values for the connector type selected.
Splice Loss Values
General splice loss values for system planning and link loss analysis are given in Table 1.36.
Specific suppliers or contractors may use other values.
NOTE: A maximum splice loss of 0.3 dB is recommended.
Table 1.36
Splice loss values in decibels
Multi mode
Splice Type
Single mode
Average
Maximum
Average
Maximum
Fusion
0.05
0.3
0.05
0.3
Mechanical
0.10
0.3
0.10
0.3
C. Verifying Performance
To verify performance, subtract the passive cable system attenuation from the link loss
budget. If the result is:
• Above zero (i.e., the passive cable system attenuation is less than the link loss budget), the
system has enough power to operate over the passive portion of the link.
• Below zero (i.e., the passive cable system attenuation is more than the link loss budget), the
system does not have enough power to operate.
NOTE: For this purpose, maximum transmitting average power should be considered.
© 2020 BICSI®
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Chapter 1: Principles of Transmission
Attenuation, continued
If the result is below zero and the system has not been installed, make design changes
(e.g., use lower loss connectors, splices, or optical fibers; reroute the design) to reduce
passive system losses. [n rare cases, it may be necessary to add active components with
greater system gains.
When working with an existing cable plant, passive cable system attenuation can be measured
directly. Remember that the test setup should simulate the actual system (e.g., use the jumpers
or at least include their losses in the final calculations).
Example link loss calculations are shown in Example 1.1.
Checking Minimum System Loss
After verifying that the electronics have enough power to operate, one more attenuation check
of the system design remains. Compare the link attenuation with the receiver's dynamic range
to ensure there is not too little loss in the link (see Table !.37).
Insufficient minimum system loss (e.g., too little loss in the link) is sometimes a problem
when a laser source is used in premises environments (where lengths are short).
To calculate the minimum required system loss, subtract the receiver's dynamic range from
the system gain (both in dB, see Example 1.1 ):
-
System gain
Receiver's dynamic range
-
Minimum required system loss
19.5 dB
16 dB
3.5 dB
Table 1.37
Minimum system loss
If the Result Is ...
Then ...
Less than zero
No further checking is necessary as it is impossible to
overdrive that transmitter/receiver combination.
Greater than zero
The resulting number represents the minimum loss that must
be introduced into the link between the transmitter and
receiver to maintain the specified BER. The total optical
fiber, connector, and splice loss must exceed this value.
Using Example 1.1:
Optical fiber loss
Connector loss
Splice loss
Total
+
+
0.6 dB
3.00 dB
0.90 dB
4.5 dB
Because 4.5 > 3.5, the system will operate as installed.
BER = Bit
TDMM, 14th edition
error rate
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© 2020 BICSJ®
Chapter 1: Principles of Transmission
Attenuation, continued
If additional loss is required in a given link, it is easy to add an appropriate link attenuator
to the system. Attenuators are devices that can be inserted into optical fiber transmission
systems, usually at a point where there is a connector, to introduce additional loss. There are
two types of attenuators:
• Fixed attenuators cause a specific level of additional loss.
• Variable attenuators can be tuned to a given link.
Determine if the minimum loss criteria are met by measuring the attenuation of each link
after it is installed.
© 2020 BICSI®
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Chapter 1: Principles of Transmission
Selecting an Optical Fiber Core Size to Application or Original
Equipment Manufacturer (OEM) Specifications
Applications standards (e.g., IEEE) specify the maximum supportable distance of each
optical fiber type for specific applications.
OEMs of optical transmission equipment also determine the maximum distance over which
their systems can operate. They recommend a specific core size and optical fiber performance
for given lengths and data rates.
Deviations from the OEM recommendations may be justified in the following circumstances:
• Optical fiber selection is made during the cabling design process and before the selection of
active components.
• Cabling systems are designed for potential upgrades for which the active elements are not
yet available.
• Existing installed optical fibers are used whether or not they are the type recommended for
the particular end equipment.
Therefore, it is important for the ICT distribution designer to understand:
• The characteristics ofthe application and the active equipment.
• How the characteristics of the application and the active equipment affect optical fiber
selection.
Synchronous Optical Network (SONET) and Synchronous
Digital Hierarchy (SDH) Conce s
---------------------------------------
Similar in nature to digital hierarchy for balanced twisted-pair transmissions, standards have
been established for optical fiber carrier transmissions.
SO NET is the standard for North America, and SDH is the international standard. These two
standards are basically identical. These standards organize transmission into 81 0-byte frames
that include bits related to signal routing and destination as well as the data being transported.
The term synchronous means that all network nodes ideally derive their timing signals from
a single master clock; however, because this is not always practical, SONET and SDH can
accommodate nodes with different master clocks.
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Chapter 1: Principles of Transmission
Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy
(SOH) Concepts, continued
Table 1.38 shows the common SONET and SOH transmission rates.
Table 1.38
Common SONET and SDH transmission rates
Voice Channels
Rate Name
Data Rate (Mb/s)
STS-l/OC-1
51.84
672
STS-3/0C-3
155.52
2016
STS-12/0C-12
622.08
8064
STS-48/0C-48
2488.32
32,256
STS-96/0C-96
4976.64
64,512
STS-192/0C-192
9953.28
129,024
OC-768
39,813.12
OC-1536
79,626.12
OC-3072
159,252.24
OC == Optical carrier
STS == Synchronous transport signal
Unlike the T and E multiplex formats covered previously, SDll allows single channels to be
extracted from the signal at any of the data rates. This makes it far more flexible and cost
effective.
Other key advantages of SOH are that the line-side transmission format and alarm format
are identical between all vendors, which allows for greater equipment choice. Previously, the
transmit and receive terminals had to be from the same vendor to ensure compatibility.
The SOH concept is based around the ability that any signal from a lower order multiplex
stage can be inserted directly into a higher order signal.
© 2020 BICS!®
TDMM, 14th edition
Chapter 1: Principles of Transmission
System Example
Prior to the optical transmitter receiving the electrical signal, there may be some conditioning
or multiplexing of the electrical signal for use on the optical network. For typical LAN
applications, either no changes are made to the electrical signal, or the signal is slightly
modified to be placed in the proper optical format.
NOTE: See Chapter l 5: Data Networks for more information.
For channel transmissions, specifically synchronous transmissions such as DSX and SONET,
often the individual channels are multiplexed prior to being sent to an optical receiver.
Figure 1.31 illustrates a configuration that multiplexes like-DSX signals onto one or more
optical fibers.
Figure 1.31
DSX optical multiplexing design
COT
f---~1-1.----.····
mux
...
/1 ~~~~:~:::connect;o~:c~;:~~
CP<O~[Jgu[J.
;
'
~ptical~7
fiber cables
Single
optical fiber
jumpers
COT=
demux =
OS=
DSX =
mux =
RT =
:
~--.
RT
d
e
m
u
X
'
'
s
[.
X
i•
i•
D
!•
1•
!
DS-()
signals
Central office terminal
Demultiplexer
Digital signal
Digital signal cross-connect
Multiplexer
Remote terminal
TDMM, 14th edition
1-118
© 2020 BICSI®
Chapter 1: Principles of Transmission
System Example, continued
Figure 1.32 illustrates a configuration that multiplexes ditTerent types of signals onto SONET.
Figure 1.32
SONET multiplexing design
Remote terminal
Central office
,---
Switch
1---
M
Dt-
Optics
and
common
controls
®--
k0-
Toother
Optics
-1
remote
and
terminals
common
SO NET
SO NET
transport
transport controls
F
~
Special
services
Channel
banks
Channel
banks
Interoffice
application
(e.g., DCS,
fiber mux,T1)
DCS =
ISDN =
MDF =
mux =
POTS=
SO NET=
•
•
•
•
•
T1
POTS
High-speed data
Special services
ISDN
Digital cellular system
Integrated services digital network
Main distribution frame
Multiplexer
Plain old telephone service
Synchronous optical network
WDM is an alternative means of multiplexing signals onto an optical fiber system. WDM
multiplexes multiple electrical signals to separate optical wavelengths at the source that are
sent along one optical fiber to its receiver at the opposite end. To accomplish this, WDM uses
a series oflenses to refract and direct light pulses into a single optical fiber that carries the
combined wavelengths.
At the other end of the optical fiber cable, a WDM receiver separates the wavelengths and
converts them to separate electrical signals. WDM may also be used to enable a single
optical fiber to both transmit and receive. WDM is most commonly used in long-haul, highbandwidth data transmissions.
© 2020 BICSI®
1-119
TDMM, 14th edition
Chapter 1: Principles of Transmission
System Example, continued
Figure 1.33 illustrates WDM being used to transmit three separate 90 Mb/s signals over a
single optical ftber.
Figure 1.33
WDM
Wavelength 1
90 Mb/S
system A
Wavelength 1
/#
90 Mb/s
system A
/ ·
Single fiber path
Wavelength 2
WDM
filter
(mux)
90 Mb/s
system B
Wavelength 3
~
90 Mb/s_(/)
system C ~
Wavelength 2
WDM
filter
( demux)
90 Mb/s at wavelength 1
and
90 Mb/s at wavelength 2
and
90 Mb/s at wavelength 3
90 Mb/s
system B
90 Mb/s
system C
demux = Demultiplexer
mux = Multiplexer
WDM = Wavelength division multiplexer
TDMM, 14th edition
1-120
© 2020 BICSI®
Chapter 1: Principles of Transmission
ndix
North American Digital Signal (OS)
The levels of multiplexing used in North America are DSO, DSl, DSIC, DS2, and DS3.
Digital Signal level Zero (DSO)
The lowest level of digital carrier is known as DSO. In PCM systems, a DSO channel contains
64 kb/s of information.
Digital Signal level One (DSl)
The first level ofTDM is DS l, which:
• Uses a transmission rate of 1.544 Mb/s.
• Can transmit up to 64 kb/s data over any one of 24 channels if the transmission system has
clear channel capability.
NOTE: Many systems can transmit only up to 56 kb/s per channel because of pulse density
requirements of clock recovery.
• Js capable of handling 24 standard (31 00 Hz bandwidth) analog voice channels when
standard 64,000 b/s PCM is used. Forty-eight voice channels are available if 32,000 b/s
ADPCM encoding is used.
• Can operate over standard balanced twisted-pair cables within specific distance limits and
design conditions.
NOTE: The transmit and receive pairs are normally separated in non-adjacent binder groups
or screened compartments.
• ls widely used for short-haul carrier transmission (up to ;::;322 km [200 mi]).
A DS I rate system without clear channel capability is capable of handling approximately
1344 kb/s of data (24 x 56 kb/s); 1536 kb/s of data (24 x 64 kb/s) can be handled if clear
channel capability is available. Therefore, these systems can be used with wideband data
terminals.
Repeater T1 carrier operated at the DS 1 rate is coded bipolar AMI with a 50 percent duty
cycle.
1-121
TDMM, 14th edition
Chapter 1: Principles of Transmission
North American Digital Signal (DS), continued
Digital Signal level One C (DSlC)
T'he special requirements for T2 carrier led to the development of an intermediate level,
known as OSlC (TIC), which:
• Uses a process called pulse stuffing to synchronize the two DS 1 signals.
• Makes more use of existing cable plant for short and medium distances.
• Has not been designated for use with higher level multiplexing.
• Can transmit two DS 1 signals (48 voice cha1mels total) at a 3.152 Mb/s transmission rate
(OS 1C rate).
NOTE: This system is no longer being deployed.
Digital Signal level Two (DS2)
The second full level of multiplexing is DS2, which:
• Typically handles four OS 1 channels, for a total of 96 voice channels.
• Employs a 6.312 Mb/s pulse stream.
NOTE: This is slightly more than four times the DS 1 rate because of bit stuffing.
For distances beyond ::::::300m (984ft), T2 carrier requires special balanced twisted-pair cable
(e.g., low-capacitance [locap cable]) that has special crosstalk and attenuation characteristics.
Balanced twisted-pair systems using T2 carrier are obsolete; however, low-speed optical fiber
systems carry DS2 signals.
Digital Signal level Three (DS3)
The DS3 level is seeing increased use between customer locations and between customer and
main entrance facility locations.
The DS3 level:
• fs used to multiplex 28 OS 1 or 7 DS2 signals at 44.736 Mb/s.
• Is a common speed for optical fiber and digital radio systems.
• Uses bit stuffing to synchronize the incoming OS I or DS2 streams to the multiplex terminal.
TDMM, 14th edition
1-122
© 2020 BICSJ:®
Chapter 1: Principles of Transmission
North American Digital Signal (OS), continued
Higher levels
Higher levels of multiplexing and carrier transmission are summarized in 'T'able 1.39.
Table 1.39
Levels of multiplexing and carrier transmission in North America
Digital
Signal
Rate
(Mb/s)
Channels
Facility
DSl
1.544
24
Paired cable
Basic North American
system
DSIC
3.152
48
Paired cable
Expansion system for
existing DS-1
DS2
6.312
96
DS3
44.736
672
Speciallocap
paired cable or
optical fiber
Optical fiber,
digital radio, or
coaxial cable
DS4
274.176
4032
DSl
DSlC
DS2
DS3
DS4
© 2020 BICSI®
=
=
=
=
=
Digital
Digital
Digital
Digital
Digital
signal
signal
signal
signal
signal
level
level
level
level
level
Optical fiber,
microwave radio,
or coaxial cable
Notes
High-density
long-haul system
1
1C
2
3
4
1-123
TDMM, 14th edition
Chapter 1: Principles of Transmission
European E
The levels of multiplexing used in Europe are El, £2, £3, and £4.
B Channel
A single 64 kb/s channel is sometimes referred to as a B channel.
El level
The first level of'T'DM is E l, which:
• Uses a transmission rate of2.048 Mb/s.
• Can transmit up to 64 kb/s data over any one of 30 channels if the transmission system has
clear channel capability.
NOTE: Two additional 64 kb/s channels perform alignment and carry signaling.
• Is capable of handling 30 standard (3100Hz bandwidth) analog voice channels when
standard 64 kb/s PCM is used. 60 voice channels are available if 32 kb/s ADPCM encoding
is used.
• Can operate over standard balanced twisted-pair cables within specific distance limits and
design conditions.
NOTE: The transmit and receive pairs are normally separated in non-acUacent binder
groups or screened compartments.
• Is widely used for short-haul carrier transmission (up to ::::;322 km [200 mi]). A repeated
carrier operated at the El rate is coded bipolar HDB3.
E2 level
The second full level of multiplexing is E2, which:
• Typically handles four E I channels for a total of 120 voice channels.
• Employs an 8.192 Mb/s pulse stream.
For distances beyond ::::;300 m (984ft), E2 carrier requires special balanced twisted-pair cable
(e.g., locap cable) that has special crosstalk and attenuation characteristics. Balanced twistedpair system.s using E2 carrier are obsolete; however, low-speed optical fiber systems carry E2
signals.
E3 level
The E3 level is seeing increased use between customer locations and between customer and
main entrance facility locations. The E3 level:
• Is used to multiplex four E2 signals at 34.816 Mb/s.
• Is a common speed for optical fiber and digital radio systems.
• Uses bit stutiing to synchronize the incoming E2 streams to the multiplex terminal.
TDMM, 14th edition
1-124
© 2020 BICSI®
Chapter 1: Principles of Transmission
European E, continued
Higher levels
Higher levels of multiplexing and carrier transmission are summarized in Table 1.40.
Table 1.40
Levels of multiplexing and carrier transmission in Europe
Digital Signal
Rate
(Mb/s)
El
2.048
E2
Facility
Notes
30
Paired cable
Basic system
8.192
120
Speciallocap
paired or coaxial cable
or optical fiber
E3
34.816
480
Optical fiber,
digital radio, or
coaxial cable
E4
139.264
1920
Optical fiber,
microwave radio,
or coaxial cable
El
E2
E3
E4
= European
= European
= European
= European
Channels
High-density
long-haul
system
1
2
3
4
1-125
TDMM, 14th edition
Chapter 2
Electromagnetic
Compatibility
Chapter 2 discusses EMC as it applies to ICT structured
cabling systems and networks. It includes discussions
on EM spectrum, sources ofEMI, RFI, factors affecting
EMI and its mechanisms, ESD, EFT, filtering and
other techniques deployed to mitigate EMI in cabling
systems.
Chapter 2: Electromagnetic Compatibility
Table of Contents
Electromagnetic Compatibility (EMC) .•...•...............•••... 2-1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Electromagnetic Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . • • • . . . . . 2-2
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Radio Spectrum Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Need for Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Specific Telecommunications Electromagnetic Compatibility (EMC) Guidelines .... 2-5
Responsibility for Electromagnetic Compatibility (EMC) . . . . . . . . . . . . . . . . . . . . 2-5
Electromagnetics .
Ill
Ill
Ill
Ill
1!11
•••
Ill
••
Ill
Ill
a
•
ll
Ill
•
Ill
••
1!11
II
a
a
Ill
•
1!1
•
Ill
II
••••••
Ill
Ill
Ill
•
2-6
Electromagnetic Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Desirable and Undesirable Electromagnetic Fields . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Sources of Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
External and Internal Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . . . . 2-6
Evidence of Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Radio Frequency Interference (RFI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Measuring Electromagnetic Compatibility (EMC) . . . . . . . . . . . . . . . . . . 2-9
Evaluating the Electromagnetic Environment . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Electromagnetic Interference (EMI)-A Problem • . . . . . . . . . . . . . . . . 2-12
Factors Affecting Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . . . . . . 2-12
Electromagnetic Compatibility (EMC)-The Solution .•...........• 2-15
Basic Philosophy of Electromagnetic Compatibility (EMC) . . . . . . . . . . . . . . . . . . 2-15
Product Immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15
Electromagnetic Interference (EMI) Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . 2-15
Sources of Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . . . . . . . . . . . 2-16
Electromagnetic Interference (EMI) and Cabling ..•••••••••...... 2-18
Cables as Electromagnetic Interference (EMI) Producers . . . . . . . . . . . . . . . . . . 2-18
Susceptibility of Cables to Electromagnetic Interference (EMI) . . . . . . . . . . . . . . 2-18
Electromagnetic Qualification Parameters . . . . . . . . . . . . . . • . . . . . . . 2-19
Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
Electrostatic Discharge (ESD) Related to Telecommunications Cabling . . . . . . . . . 2-20
Radiated Immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Electrical Fast Transient (EFT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Transient Voltages and Currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
© 2020 BICSI®
2-i
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Unwanted Signals . ................
II
•••••••••••••••••
1!1
•••••
II
2-24
Types of Unwanted Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24
Common Mode (CM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24
Differential Mode (DM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Sources of Unwanted Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Electrical Power Converters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Logic Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26
Other Internal Unwanted Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26
Electrical Power Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26
Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26
Grounding (Earthing)
II
•••
Ill
•••••••••••
I!
••••••••••••••
"
~~
•••••
2-27
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27
Ground Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27
Alternating Current (ac) Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29
Unwanted Signal Coupling Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30
Conduits, Cable Trays, and Raceways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32
Shields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Cable Shielding and Shield Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Considerations about Shield Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . 2-34
Minimizing Electromagnetic Interference (EMI) ............•.... 2-35
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
Design of Horizontal Pathways and Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
Considerations for Electromagnetic Compatibility (EMC) in
Cabling Systems
a
II
II
II
II
II
•
II
II
II
II
II
II
II
II
•
II
II
II
II
•
B
•
II
111
II
II
II
II
•
II
••
Ill
Ill
1!1
II
•
II
II
•
II
2-36
General Guidelines to Promote Electromagnetic Compatibility (EMC) . . . . . . . . . . 2-36
Cable Separation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
Electromagnetic Interference (EMI) Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39
Data Line Filtering-Isolation Transformers . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
Electromagnetic Compatibility (EMC) by Filtering . . . . . . . . . . . . . . . . . . . . . . . 2-41
Interference Reduction in Shielded Rooms .•................•.• 2-42
Electromagnetic Interference (EMI) and Bandwidth of Balanced Twisted-Pair
Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42
Balance of Twisted-Pair Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42
Telecommunications Cabling within Joint-Use Tunnel .......•.•.•• 2-44
Electrical Power Line Influence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-44
Coupling from Mutual Capacitance and Inductance . . . . . . . . . . . . . . . . . . . . . . 2-44
Reducing Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-44
Susceptibility of Circuits and Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
Recommended Longitudinal Balance (Immunity) . . . . . . . . . . . . . . . . . . . . . . . . 2-48
TDMM, 14th edition
2-ii
© 2020 BICSI®
Chapter 2.: Electromagnetic Compatibility
Figures
Figure 2.1
Electromagnetic spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Figure 2.2
Dependence of the safe distance to EMI source on its power ........ 2-10
Figure 2.3
Model T for a short wire channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21
Figure 2.4
Surge test voltage waveform sample . . . . . . . . . . . . . . . . . . . . . . . . . 2-23
Figure 2.5
CM versus DM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25
Figure 2.6
Ground loops in shielded cabling systems . . . . . . . . . . . . . . . . . . . . . 2-28
Figure 2. 7
Ground loop because of stray capacitance at high frequencies ....... 2-29
Figure 2.8
Common impedance coupling interference . . . . . . . . . . . . . . . . . . . . . 2-30
Figure 2.9
Field-to-cable and ground loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31
Figure 2.10
Coupling reduction as function of grounding (earthing) practice ...... 2-32
Figure 2.11
Higher frequency twist decrease . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Figure 2.12
Typical power line filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39
Figure 2.13
Isolation transformer scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
Figure 2.14
Samples of ferrite toroids, beads, and sleeves . . . . . . . . . . . . . . . . . . 2-41
Figure 2.15
Balance concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
Figure 2.16
EMI susceptibility of circuits and systems connected through
unshielded cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
Figure 2.17
Ground loop and EMI immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47
Tables
2-12
Table 2.1
Factors that can affect EMI in telecommunications equipment
Table 2.2
Factors that can affect EMI in sites . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
Table 2.3
Four levels of immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19
Table 2.4
ESD susceptibility ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
Table 2.5
Mutual capacitance ranges for telecommunications cables . . . . . . . . . . 2-21
Table 2.6
Minimum separation distances from possible sources of EMI
exceeding 5 kVA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
Table 2.7
Separation requirements between metallic cabling and specific EMI
sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
© 2020 BICSI®
2.-iii
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Electromagnetic Compatibility (EMC)
Introduction
EMC is the ability of a device, equipment, or system to operate properly in its intended
electromagnetic environment without introducing significant EMI into the environment.
EMI is the transfer of electromagnetic energy from one device or system to another device or
system operating in the same environment that causes interference with the normal operation
of devices or systems.
The potential for EMI increases when devices or systems share a common electromagnetic
environment and their operation's frequencies overlap. If they operate over a different range
of the electromagnetic spectrum, lower levels of EMI between them are expected.
The coupling between two circuits or systems can occur because of one or more of the
following mechanisms:
• Conductive coupling (when a common branch circuit is shared between two devices)
• Inductive coupling (by magnetic fields)
• Capacitive coupling (by electric fields)
• Electromagnetic coupling (by electromagnetic fields and waves)
Three essential elements to any EMC problem are:
• The source of an EMI or electromagnetic energy transfer between an interfering source and
a susceptible device or system.
• The susceptible device or system that cannot perform as designed, configured, or
programmed because of the EMI event.
• A coupling path that promotes the disturbance between the interfering source and the
susceptible device or system.
Mitigate EMC problems by identifying at least two of these elements and eliminating, or
reducing the influence of, the third one.
© 2020 BICSI®
2-1
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Electromagnetic Spectrum
Overview
EMR is radiation composed of oscillating electrical and magnetic fields and propagated
through a medium. EMR includes gamma, X-ray, UV, visible (i.e., light), and lR radiation as
well as radar, microwaves and radio waves. All of these are fundamentally similar in that they
propagate at the speed of light (;.=:;300,000 km/s [186,300 mils] in a vacuum).
Electromagnetic waves are distinguished by their wavelength, which is expressed in meters,
or their frequency, which is expressed in hertz:
'A= elf
Where:
f = frequency in hertz
)c =
wavelength in meters
c
velocity of light in meters per second in a vacuum
=
The entire spectrum is the range of frequencies of EMR fl-01n zero to infinity.
Radio Spectrum Groups
The electromagnetic spectrum was formerly divided into 26 alphabetically designated bands.
This usage still prevails to some degree. However, the ITU recognizes 12 bands from 30 Hz
to 30,000 GHz:
• ELF, ITU Band 1 = 3 Hz to 30 Hz
• SLF, ITU Band 2 =30Hz to 300Hz
• VF, ITU Band 3 (ULF)
=
300 Hz to 3000 Hz
• VLF, ITU Band 4 ""' 3 kHz to 30 kHz
• LF, ITU Band 5 = 30 kHz to 300kHz
• MF, ITU Band 6 = 300 kHz to 3 MHz
• HF, ITU Band 7-e.g., aviation communications and RFID
=
3 MHz to 30 MHz
• VHF, ITU Band 8-e.g., FM radio= 30 MHz to 300 MHz
• UHF, ITU Band 9-e.g., mobile phones and wireless LAN = 300 MHz to
3000 MHz (3 GHz)
• SHF, ITU Band 10-e.g., radar and microwave radio= 3 GHz to 30 GHz
• EHF, ITU Band 11-e.g., radio astronomy and millimeter wave scanner= 30 GHz to
300 GHz
• THZ, lTU Band 12-e.g., medical imaging = 300 GHz to 3000 GHz (3 THz)
NOTE: See Figure 2.1 for a representation of the electromagnetic spectrum.
TDMM, 14th edition
2-2
© 2020 BICSI®
Chapter 1: Electromagnetic Compatibility
Radio Spectrum Groups, continued
Figure 2.1
Electromagnetic spectrum
Frequency (hertz)
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Wavelength (m)
1-lm
A
AM
em
EHz
FM
GHz =
IR =
km =
LW =
Micrometer (or micron), 1
Angstrom, 1 x 10· 10 m
Amplitude modulation
Centimeter, 1 x 10· 2 m
Exahertz, 1 x 10 18 Hz
Frequency modulation
Gigahertz, 1 x 10 9 Hz
Infrared
Kilometer, 1 x 10 3 m
Long wavelength
X
10
6
m
m =
MeV=
mm
Mm
nm
PHz
THz
UHF=
VHF=
Meter
Megs (million) electron volts
Millimeter, 1 x 10·3 m
Mega meter, 1 x 10 6 m
Nanometer, 1 x 10·9 m
Petahertz, 1 x 10 15 Hz
Terahertz, 1 x 10 12 Hz
Ultrahigh frequency
Very high frequency
For example, visible light represents only a small portion of the electromagnetic spectrum.
Toward one end of the spectrum are radio waves with wavelengths approximately one billion
times longer than those of visible light. Toward the other end of the spectrum are gamma
rays. These have wavelengths approximately one million times smaller than those of visible
light.
·rhe potential for EMI occurs when devices or systems share a common electromagnetic
environment and their frequencies of operation overlap. If the devices or the systems operate
over a different range of the electromagnetic spectrum, lower levels of EMJ between them are
expected.
Need for Compatibility
Electronic equipment is becoming increasingly more sophisticated, and the required
performance levels, operating speeds, and frequencies are rising. These more sophisticated
electronic systems use solid-state devices that, by their nature, are more susceptible to EMI.
Operating these electronic telecommunications systems requires a Jess deliberate electrical
energy that must only be strong enough to accomplish a change of the charged particle energy
level within the electronic device. Unwanted electrical signals (voltage or current) can cause
the same effects as this electrical energy.
© 1020 BICSI®
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Need for Compatibility, continued
Because of the material-based construction and small size (volume) of electronic devices,
electrical power quality considerations (e.g., ac line voltage sags, swells, capacitively or
inductively coupled currents) are crucial. High-voltage, low-energy signal bursts can cause
some electronic devices (e.g., logic gates) to go into a self-latching mode.
Conducted coupling may affect electronic devices primarily through:
• Input signal lines.
• Output signal lines.
• Utility or premises electrical power distribution.
Radiated interference enters electronic devices primarily by means of:
• Proximity to interfering sources.
• Missing or inadequate gaskets/enclosures.
• Missing or inadequate bonding and grounding (earthing) system components.
• Missing or inadequate device or cable shielding.
The ICT distribution designer shall take precautions in the design, procurement, and
installation to protect against EMI and ensure EMC.
These precautions should involve interaction and interdependence among the following:
• ac or de power distribution
• Bonding and grounding (earthing) system components
• Transient voltage surge protection on ac electrical and ICT signal paths
• Cabling
• Shielding
• Filtering
• Interface design
Electrical codes do not generally provide for EMC. For example, telecommunications
installations that experience malfunctions and failures could have deficiencies within the ac or
de electrical power and bonding and grounding (earthing) system even though the installation
of both is code compliant.
Additionally, commercial building bonding and grounding (earthing) standards focus on the
infrastructure of a building and often do not cover:
• Tolerances related to surge current immunity and component insulation to withstand
electromagnetic disturbance and surge voltages and currents.
• The specific methods for RFT and EMI mitigation for equipment or systems.
TDMM, 14th edition
2-4
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Specific Telecommunications Electromagnetic Compatibility (EMC) Guidelines
When designing a telecommunications system, regulations typically relate to an electronic
system as a whole and not to any specific component, especially a passive one (e.g., cable).
When designing any electronic system, select a cable designed to keep interference at a level
below the regulatory limits. The equipment manufacturer should provide a recommendation
of cable types for approved regulatory operations.
When designing a cabling system for critical environments in terms of EMI, the ICT
distribution designer shall follow cable separation guidelines presented in this chapter.
Responsibility for Electromagnetic Compatibility (EMC)
An lCT distribution designer is not directly responsible for the EMC of ICT. However, being
properly informed and knowledgeable can greatly contribute to the EMC of the installation.
In complex situations, consult an EMC specialist. Before beginning EMC steps, verify the
requirements given in Chapter 8: Bonding and Grounding (Earthing).
© 2020 BICSI®
2-5
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Electromagnetics
Electromagnetic fields
An electromagnetic field is an area of energy that surrounds electrical devices. It is a
combination of an electric field (created by stationary charges) and a magnetic field (created
by moving charges [electric currents]).
The relationship between electromagnetic fields and current-carrying conductors and the
resulting effects on communications cable networks and electronic equipment initiated the
study of EMC and EML
Desirable and Undesirable Electromagnetic fields
Electromagnetic fields can be both desirable and undesirable, depending on whether the
electromagnetic fields interfere with the operation of the network or electronic devices
(e.g., the TV broadcast signal is a desirable electromagnetic field for a TV set but may not be
for an AM/FM receiver).
The electromagnetic fields that have undesirable effects on the device, equipment, or system
being considered are referred to as EML
Sources of Electromagnetic Interference (EMI)
A variety of EMI sources may contribute to the electromagnetic environment. Usually, in a
given application, only a few EMI sources are significant. A broad classification of sources
of EMI is useful, and they can be classified as transient or continuous sources (e.g., low- or
high-frequency magnetic or electric fields). They can also be classified as natural sources
(e.g., lightning). These also may be intentional or unintentional in nature.
External and Internal Electromagnetic Interference (EMI)
Extemal EMf sources are typically:
• Radio transmitters/receivers.
• Electrical power lines.
• Radar.
• Cellular phones.
• Engine ignitions.
• Lightning.
• ESD when responsible for coupling noise into circuits and systems.
• Electric motors.
• Electronic ballasts.
Control of external EMI sources is not normally practical, so the ICT distribution designer
shall revert to methods that promote system immunity.
TDMM, 14th edition
2-6
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
External and Internal Electromagnetic Interference (EMI), continued
Internal EMI sources arc typically:
• Electrical power supplies.
• Electrical power cables.
• Rectifiers.
• Oscillators.
• Digital clocks.
• Digital signal processors.
• CM signaling.
• Long-term or short-term variations in ac voltage (e.g., sags, swells, undervoltages).
• Unbalance of current between ac circuit conductors.
• Power signaling systems.
• Power conditioners (e.g., UPS).
Internal EMI sources are usually easier to control since it is possible to reduce the emissions
at the source. Runs of unshielded and untwisted conductors in balanced twisted-pair cables
are susceptible to external unwanted signal emissions because they can behave as antennas.
A signal in a conductor can be coupled as unwanted signal to adjacent conductors running
in close proximity. Telecommunications network cabling also can conduct EMI unwanted
signal generated from internal sources and radiate or couple the EMI unwanted signal to other
conductors.
The amount of radiation or coupling depends on the level of the CM voltage (Yc111 ) at the
output of the transmitter. For unshielded balanced twisted-pair circuits, the amount of
radiation or coupling also depends on the level of differential-to-eM signal conversion of the
cabling. Asymmetrical twisted-pair geometry, unbalanced connector designs, or excessive
untwisting at cable terminations causes this conversion.
Evidence of Electromagnetic Interference (EMI)
Some examples of the causes and effects ofEMI are:
• The visual interruption or distortion of a video signal on a TV when a source of disturbance
(e.g., vacuum cleaner) shares the TV's power source.
• An audible distortion in signal such as when a radio tuned to an AM frequency is in
proximity to a power line or similar interfering sources.
• The physical damage or degradation to components of lCT equipment when affected by
lightning-induced surges near or within the equipment environment.
• The visual distortion of a video display terminal screen when in close proximity to devices
that produce strong magnetic field strengths (e.g., fluorescent lighting, transformers, ac
power circuits).
• The degradation of electronic components that are subjected to repeated ESD.
• The manifestation of bit parity errors or loss of signal on voice or data transmission
because of interfering sources affecting the paths in which this information is transferred
(e.g., the proximity of unshielded cables placed near ac power circuits).
© 2020 BICSI®
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TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Radio Frequency Interference (RFI)
While EMI and RFI are commonly used interchangeably, RFI is a form of EMI. RFl can be
defined as the degradation of a desired signal at the receptor end caused by radio frequency
disturbance within the radio frequency spectrum which is usually comprised in the frequency
range that includes LF, MF, HF, and VHF.
Immunity of telephone sets or other equipment to RFI from commercial broadcast stations
and other radio services in relation to building cabling may be obtained by the deployment of
shielded or screened structured cabling systems in concerned areas. Usually, this is the only
reliable and effective technique to mitigate RFI effects on telephone sets and other equipment.
Copper conductors or their sheaths may inadvertently act like antennae under certain
conditions and pick up interference from radio stations in their proximity, thus coupling
undesired signals on telephone sets and other equipment connected to them. Building cabling
practices combined with an effective bonding and grounding (earthing) infrastructure can
affect a given telephone set's ability to function in the presence of radio signals.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 1: Electromagnetic Compatibility
Measuring Electromagnetic Compatibility (EMC)
A device's EMC is not easily determined since its value is relative to the environment in
which it will operate. There are no specific techniques or units to measure EMC; however,
there is a need for measurable parameters to establish the tests and standards used to ensure
that all the elements of a system are compatible. Measuring and setting limits on emission
and immunity (the two components of EM C) obtain the measurable standards.
Measuring the electrical and magnetic field strength of the outgoing radiation determine
radiated emissions. The unit of measure for the electric field strength is volts per meter,
millivolts per meter, or microvolts per meter. The use of each depends on the amplitude of the
electric field strengths.
The magnetic field unit of measure is amperes per meter. Measurements of conducted
interference are normally taken over a frequency spectrum of 100kHz to 30 MHz.
Measurements of radiated interference are normally taken over a frequency spectrum of
30 MHz to 5 GHz. Another unit often used to measure narrowband electric field strength is
decibel above a reference level of one microvolt.
If the resulting measurements are below specified limits, the device being measured is
electromagnetically compatible relative to emissions and conducted interference.
Immunity to radiated emissions is determined by exposing the device being measured to
a specified electromagnetic field and monitoring its performance (see Figure 2.2). If there
is no undesirable response from the device, it is electromagnetically compatible relative to
immunity. Radiated interference limits are set on measurements taken by means of resonant
dipoles at a distance (e.g., :::o3 m [1 0 tt] for FCC Class B and :::o 10m [33 ft] for FCC Class A).
© 1020 BICSI®
2-9
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Measuring Electromagnetic Compatibility (EMC), continued
Figure 2.2
Dependence of the safe distance to EMI source on its power
Electromagnetic field strength
10,000
1000
.---._
E
100
QJ
u
c
ro
10
.j.J
(/)
0
1
Source output power (W)
Calculations in Figure 2.2 are based on the following engineering evaluation formula:
E;::-;
~30x W
d
Where:
, V/m
E
=
electromagnetic field strength in volts per meter
W
=
source output power in watts
d
=
distance to the source in meters
In practical measurements of radiated emissions from equipment, systems, or instruments,
the interest is in measuring its electric field strength at a specified distance. A number of
approaches can be adopted for doing these measurements.
Methods and apparatus for measurements of radiated and conducted interference are:
• Open area test site.
• Radiated interference measurements:
- Anechoic chamber.
- TEM cell.
Reverberating chamber.
- GHz TEM cell.
• Conducted interference measurements:
- CM and DM interferences.
- Conducted electromagnetic noise on power supply lines.
- Conducted EMI from equipment.
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© 2020 BICSJ®
Chapter 2: Electromagnetic Compatibility
Evaluating the Electromagnetic Environment
When sources of EM! are not easily identifiable or when they are known but additional
assurance is required, these methods can be recommended to evaluate the potential for
an electromagnetic environment in the areas where the telecommunications cabling or
equipment is to be installed:
• Electric field intensity meter--The acceptance criteria is 3 V/m maximum for generalpurpose telecommunications equipment and cabling. If measured field intensities are above
3 V /m, the appropriate type of shielding should be considered.
• Trial installation of a cabling link--If there is a suspicion that an area has elevated
EM I levels, the field testing of the trial link may show if it can work reliably in that
electromagnetic environment. The major parameters that will fail field testing in the
presence of elevated EMI will be parameters of the crosstalk group (e.g., NEXT, ANEXT).
Terminology
The terms EMJ, EMC, and RFl are often mistakenly used to describe items with different
attributes. As a result, communication errors may occur between the ICT distribution designer
and the client. It is important to use precise terminology and to clarify with the client that the
terms being used are mutually understood.
NO'fE: Refer to the Glossary for key terms and definitions.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Electromagnetic Interference (EMI)-A Problem
Factors Affecting Electromagnetic Interference (EMI)
Typical circumstances that can affect EMI in telecommunications equipment are shown in
Table 2.1.
Table 2.1
Factors that can affect EMI in telecommunications equipment
Telecommunications
Equipment Issue
EMI Factors
Central or remote processing
unit
• Clock signal leakage
- Circuit noise
-Frequency switching
Interconnecting cables
• Excessive lengths of unshielded cable between rooms of buildings
Interconnect interface scheme
• Unbalanced signaling
• Poor dielectric strength between electronic components
Components
• Improper logic family
• Unmatched critical pairs
• Inherently noisy for the application
Alternating current surge
protection
• Add-on unit not properly grounded surge protection
• Add-on unit not selectively coordinated
• Incorrect model and specifications
• Improper or conflicting technology
• Used where not needed
• Improperly cabled or missing
Electrical power quality
• Vague or missing specifications
• SMPS clock signal leakage
• Excessive third harmonic distortion for load conditions
• SMPS unmatched to electrical power source
• Internal supply capacity too low
Product compliance
• Inadequate or missing specifications
• Electrostatic discharge levels too low
• Susceptible to pulsed EMI such as arcing
• Susceptible to conducted and radiated EMI
Product safety
• Product listing (compliance) to wrong standard
• Not listed as a system
• Violation of listing requirements
• Improper use of exemption
Installation
• Instructions too interpretive
• Inadequate instructions
• Instructions may cause code violations
• Inadequate commissioning instructions
• Inconsistencies because of site conditions
TDMM, 14th edition
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© 2020 BICSJ:®
Chapter 2: Electromagnetic Compatibility
Factors Affecting Electromagnetic Interference (EMI), continued
Table 2.1, continued
Factors that can affect EMI in telecommunications equipment
Telecommunications
Equipment Issue
EMI Factors
Seasonal and cycling events
• No shutdown or recovery software
• Arcing from contactors (e.g., heating)
Value-added
• No compatibility guidelines
Original equipment
manufacturer devices
• Nonstandard interface schemes
• No common grounding (earthing) or embedded electrical power
EMI = Electromagnetic interference
SMPS =Switched mode power supply
Typical circumstances that can affect EMI in sites are shown in Table 2.2.
Table 2.2
Factors that can affect EMI in sites
Site Issue
EMI Factors
Branch distribution
• Overloaded circuits and extension cords and outlets
• Improper surge protection devices
• Overcurrent protection device not selectively coordinated
• Cyclic loads (e.g., welder, heater, copier)
• Incorrect and insecure connections
Commercial and standby ac
• Incorrect cabling and connections
• Incompatible standby transfer switch
• Poor electrical power quality
• Non-metallic conduit used for electrical power system raceway
Electrical service entrance
• Incorrect or missing grounding (earthing) electrode
• Connectors are not compliant with national requirements or
best practices
• Incorrect system grounding (earthing)
• Incorrect or missing ac surge protection device
EMf emitters
• Two-way radios
• Broadcasting towers
Environmental control
• Incorrect or missing temperature control
• Incorrect or missing humidity control
Feeder distribution
• Inconect cabling and connections
• Incorrect or missing grounds
• Multiple electrical power system neutral ground
Grounding (earthing) electrode
• Incorrect or missing electrode system
• Not integrated into telecommunications grounds
© 2020 BICSI®
TDMM, 14th edition
Chapter 2: Elecl:romagnel:ic Compatibility
Factors Affecting Electromagnetic Interference (EMI), continued
Table 2.2, continued
Factors that can affect EMI in sites
Site Issue
EMI Factors
Lightning protection system
• incorrect or missing at exposed site
• Not compliant with industry requirements
Load power conditioning
• Poor electrical power quality
• Not matched to load
• Load balancing
• Overcurrent protection device not selectively coordinated
• Incorrect or missing connections
Maintenance
• Poor, inadequate, or lack of maintenance
Materials
• Not listed for the purpose (i.e., not compliant with industry
requirements)
• Improper conductivity and dielectric strength
• No regard to circuit functionality
Telephone distribution
• Unbalanced cabling
• Incorrect or missing primary protectors
• Incompatible secondary protectors
• Incorrect or missing grounds
Telephone entrance
• Located remote to electrical entrance
• Incorrect or missing grounds and bonds
• Incorrect or missing fuse links
• lnconect or missing connections
Workmanship
• Unqualified installers
ac = Alternating current
EMI = Electromagnetic interference
TDMM, 14th edition
2-14
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Electromagnetic Compatibility (EMC)-The Solution
Basic Philosophy of Electromagnetic Compatibility (EMC)
EMC aims to ensure that equipment items or systems will not interfere with or prevent each
other's correct operation through spurious emission and absorption ofEMI. 'rhus, the focus
of EMC can be seen as the control of EM I.
A significant part of accomplishing EMC depends on the following considerations:
• All EMI problems are explainable by the basic laws of physics--the EMI problem is
always a circuit.
• The real task involves narrowing a spectrum of possible EMl and EMC combinations down
to a manageable few.
• Even with good design and installation, EMI can occur as an exception to the rule. EMf
often involves "hidden" schematics or "stray" paths.
• EMI is often easy to remedy once the root cause is identified.
• EM! is a by-product of technology advancement.
• Accomplishing EMC often involves designing for threats that may or may not materialize.
It is possible for EMC methods to function well in one location and fail in another.
EMC involves probability. Each telecommunications system and location is different.
Product Immunity
Providing an EMC margin for telecommunications products greatly enhances their immunity
capability.
Electromagnetic Interference (EMI) Mechanisms
EM! problems typically come from:
• Conducted and radiated emission sources, including:
- Communications.
- Transmitters.
Radar.
Telemetry.
- Navigation.
- Motors.
-- Switches.
- Electrical power lines.
© 2020 BICSI®
2-15
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Electromagnetic Interference (EMI) Mechanisms, continued
• Transfer or propagation sources, including:
Space separation.
Shielding failures.
Poor filtering.
- Improper grounding (earthing).
Electrical power lines.
··· Input/output cabling.
• Receiving or receptor elements, including:
Receivers (all types).
Sensitive electronic components.
- Relay equipment.
Biological hazards (e.g., human).
Sources of Electromagnetic Interference (EMI)
EMI can be man-made or naturally occurring.
Natural sources of EMI include:
• Atmospheric electricity.
• Cosmic radiation or geomagnetism disturbances.
Man-made sources of EMI include:
• Electrical power:
Conversion (step up/down).
- Distribution (i.e., insulators, cabling, transformers, grounding [earthing]).
Generators.
• Communications electronics:
Broadcast AM, FM, VHF, or UHF.
Communications (non-relay) fax, telegraphy, maritime, telephone, or radio control.
Mobile (cellular) telephone communications.
PCS.
- Navigation (non-radar) aircraft beacons.
- Radar search (e.g., detection, traffic control, harbor, weather, police).
• Relay communications:
Ionospheric scatter.
Satellite relay.
- Tropospheric scatter.
TDMM, 14th edition
2-16
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Sources of Electromagnetic Interference (EMI), continued
• Tools and machines:
- Telecommunications electronic equipment.
Information technology equipment.
Industrial machines.
- Office equipment.
- Power tools.
- Material-moving equipment.
• Ignition systems:
Engines.
Tools.
-- Vehicles.
• Industrial and consumer equipment or products (non-motor/engines):
- Heaters.
- fndustrial controls and computers.
Fluorescent lights.
Medical equipment.
- Ultrasonic devices.
- Welders.
Dimmers.
Electronic ballasts.
- Appliances.
© 2020 BICSI®
2-17
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Electromagnetic Interference (EMI} and Cabling
Cables as Electromagnetic Interference (EMI) Producers
Copper cables can conduct unwanted signal or radiate an electromagnetic field when attached
to equipment.
Attached equipment includes:
• Electrical power supplies.
• Radio and TV receivers.
• CRAC units and UPS.
• Computing devices (e.g., computers, servers, routers, switches, K VM).
• 'T'elecommunications and data equipment.
Susceptibility of Cables to Electromagnetic Interference (EMI)
The transfer of unwanted signals may occur over one path or several paths. Unwanted signals
may transfer by radiation, conduction, and inductive and capacitive coupling.
Some methods used to suppress or prevent unwanted signals are:
• Shielding.
• Filtering.
• Bonding and grounding (earthing) of cable shields and equipment.
Improper shielding, filtering, and grounding (earthing) can increase EMJ susceptibility.
Alternately, equipment designed to operate over balanced twisted-pair cabling uses a
balanced (e.g., DM) signal at the output of the transmitter. For such systems, it is important
to ensure that the cabling elements are well balanced and that the pairs are not excessively
untwisted at the point of termination.
TDMM, 14th edition
2-18
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Electromagnetic Qualification Parameters
Electrostatic Discharge (ESD)
ESD is the sudden flow of electricity between two electrically charged objects caused
by contact. Tt can be a natural phenomenon in which accumulated electric charges are
discharged, creating a visible spark. Static electricity is created when two materials of
different dielectric constants rub against each other. Charging of a given body may also result
from heating or from contact with a charged body. The energy stored is then discharged to
another object, which has a lower resistance to the ground. ESD can cause EMI. Effects
of ESD can vary from noise and disturbance in devices and systems up to and including
electrical shocks to persons.
There are three types of ESD:
• Discharge through a spark in the air
• Radiated effects of ESD
• Contact discharge
Measures should be taken by the ICT distribution designer to provide a bonding and
grounding (earthing) point in all equipment locations so that personnel can use an approved
method of discharging the build up of static charge both before and during the handling of
electronic components.
Four levels of immunity are outlined for contact and air discharge. These are shown in
Table 2.3.
Table 2.3
Four levels of immunity
Type of Discharge Contact
Level Number
Contact
Voltage (l\:V) Level
2
Contact
2
4
Contact
3
6
Contact
4
8
Air
2
Air
2
4
Air
3
8
Air
4
15
Discharges of the magnitude of those in Table 2.3 are capable of inducing high-frequency
electric currents into cables in the vicinity. In addition, the current "rings" at a resonant
frequency that is low for long cables (e.g., a few MHz to tens ofMHz). This ringing can
affect equipment that otherwise might not be affected by a fast ESD event with a I 00 ns
duration.
© 2020 BICSI®
2-19
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Electrostatic Discharge (ESD), continued
Cabling systems (e.g., improperly grounded screened) in buildings may behave as antennae
for receiving and transmitting radiation from ESD events. As such, they may affect the ability
of equipment to withstand ESD. Compliance with this standard to one of its four levels of
immunity helps ensure that equipment will meet performance expectations.
Table 2.4 shows ESD susceptibility ranges for a number of devices and equipment. To
minimize equipment losses and damages, circuitry has been provided with sophisticated
protection schemes.
Table 2.4
ESD susceptibility ranges
Device
ESD Susceptibility
Voltage (V) Range
Vertical metal oxide semiconductor
30to 1800
Metal oxide semiconductor field effect transistor
100 to 200
Gallium arsenide field effect transistor
100 to 300
Erasable programmable read-only memory
100
Surface acoustic wave semiconductor devices
140 to 7000
Junction gate field effect transistor
150 to 500
Operational amplifier
190 to 2500
Complementary metal oxide semiconductor
250 to 3000
Schottky diode
300 to 2500
Resistors
300 to 3000
Bipolar junction transistor
380 to 7000
Silicon controlled rectifier
680 to 1000
Schottky transistor-transistor logic
1000 to 2500
Electrostatic Discharge (ESD) Related to Telecommunications Cabling
Although this is not common in practice, telecommunications cabling can be prone to
store some energy and then discharge it as ESD. This may happen because of the mutual
capacitance ofthe cable.
A metallic cable or a transmission line can be described in terms of distributed network
parameters (e.g., resistance, inductance, capacitance, conductance) per unit length. Generally,
the series resistance and inductance per unit length along with the shunt capacitance and
conductance per unit length can represent the wireline channel. A model (designated
Model T) for an approximate equivalent circuit for a short length is shown in Figure 2.3.
TDMM, 14th edition
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Chapter 2: Electromagnetic Compatibility
Electrostatic Discharge (ESD) Related to Telecommunications Cabling,
continued
Figure 2.3
Model T for a short wire channel
R
C
G
L
R
=
=
=
=
L
L
R
Capacitance
Conductance
Inductance
Resistance
In order to minimize crosstalk, the mutual capacitance of balanced cables decreases as the
cable category increases. The result of this (in terms of ESD) is that the potential energy
accumulation is lower for higher cable categories (i.e., a category 5e cable is more prone to
store energy than a category 6 cable). In other words, the higher the cable category, the lower
its ability to store energy.
Table 2.5 shows mutual capacitance value ranges for several telecommunications cable
categories (for information only).
Table 2.5
Mutual capacitance ranges for telecommunications cables
TIA Cable Category
ISO Class/Category
Mutual Capacitance
Range (pF/m)
Category 3
Class C/Category 3
64 to 66
Category 5e
Class D/Category 5
44 to 49
Category 6
Class E/Category 6
44 to 46
Category 6A
Class E A/Category 6 A
43 to 45
N/A
Class F/Category 7
40 to 44
N/A
Class F/Category 7;\
40 to 44
Category 8
Class 8.1
1.2
Category 8
Class 8.2
1.2
ISO = International Organization for Standardization
N/A = Not applicable
TIA = Telecomt:nunications Industry Association
NOTE: Values shown in this table are for reference only. They may vary depending on
manufacturer or dielectric used in the cable construction as well as cable type
(e.g., plenum, riser).
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TDMM, 14th edition
Chapter 2: Electromagnetic: Compatibility
Radiated Immunity
Equipment should be verified as properly tested or certified for immunity to radiated fields
within a wide frequency range (i.e., usually from a few kilohertz to gigahertz frequencies).
The standards or practices used to set guidelines should have specific performance parameters
of the equipment under test and are monitored for different levels of electromagnetic intensity
to verify its performance compliance.
Especially at the lower frequencies (up to 300 MHz), the cabling attached to a system
could affect its operation during this test. Both shielded and unshielded cabling acts as an
effective antenna, and both types of cabling can cause problems during the test if not properly
installed.
Electrical Fast Transient (EFT)
EFT disturbances are created when inductive and capacitive circuits are switched on and off
over an operation cycle. When inductive loads (e.g., timers, contactors, motors) are connected
to a power line or disconnected from a power line, a spark occurs between the mechanical
contacts of the switches. As a result, an arc between these contacts is unstable with a resulting
switching frequency changing during the process. The intermittent arc continues as long as
the voltage ofthe switching contacts is above the breakdown threshold of the spark gap.
Transient Voltages and Currents
Transient disturbances (often referred to as electrical surges) are short duration current,
voltage, or power on low-voltage electrical power lines. Transient voltages can be impulsive
or oscillatory with durations ranging from the microsecond range to less than one-half
cycle of the fundamental power frequency. Transient disturbances can have amplitudes of
up to several kiloamperes or kilovolts. These transients generate EMI as well as conducted
interference in equipment or systems in close proximity or sharing the same electrical circuit
(usually power supply lines).
The testing of equipment for immunity to surges (e.g., surges generated by lightning on
power, signal) is complicated because of the large number of interfaces that are typical in an
electronic system. As a result, surge tests are usually performed in special areas designated
for this purpose. Figure 2.4 depicts an example sample of a typical surge test voltage
waveform that is commonly employed in surge testing of equipment inputs.
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Chapter 2: Electromagnetic Compatibility
Transient Voltages and Currents, continued
Figure 2.4
Surge test voltage waveform sample
Voltage
1000
Rise time = 0.5 IJS
1.------lOjJs-----.1
'----------+--------+------+----0
10
20
Time = Microsecond (IJS)
30
NOTE: Refer to applicable standards (e.g., IEEE C62.41 Recommended Practice on Surge
Voltages in Low- Voltage A C Power Circuits and IEC 61 000-4-5) for specific surge
test procedures.
© 2020 BICSI®
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Unwanted
nals
Types of Unwanted Signals
CM and OM are the two types of unwanted signals on cable in an EMI event. CM unwanted
signals usually predominate. It happens because of the ground plane, which is shared by
source and victim. CM interference because of a radiation source induces a CM voltage, or
noise, in the loop formed by the victim circuit and the ground plane.
OM unwanted signals are coupled into a pair of conductors (victim circuit) because of
radiation from an EMI source. OM noise can also be a result of a coupling between a given
conductor and its return path. Twisting the conductors in pairs can minimize OM interference.
The ground plane is not involved in this kind of event.
To successfully filter both types of unwanted signals, a magnetic scheme is preferred. CM
unwanted signal reduction is effective when afflicted lines are coupled together through a
ferrite bead. For OM unwanted signal mitigation, individual ferrite beads can be installed on
each input lead of the victim line or output lead of the interfering circuit or line.
Common Mode (CM)
CM unwanted signal on cabling can affect equipment in two ways:
• It can directly affect equipment operation (e.g., locking up a computer). This occurs
because the CM signal gets inside the equipment and causes logical errors. Shielded and
unshielded cabling can cause this to happen if both the equipment and cabling are not
properly designed and installed.
• The CM signal can become converted to a OM signal by the cable or equipment. The
critical parameter is balance or, altematively, CM rejection ratio. The better balanced a
circuit is, the less conversion from CM to OM occurs.
CM to OM conversion is an important parameter, and its control helps to mitigate the effects
ofEMl in a given circuit or system. From the susceptibility standpoint, CM voltage can be
conve1ied into OM voltage at the input of the disturbed circuit or system. From the emission
point of view, OM voltage transmitted over a given circuit generates CM voltages and
currents along the ground loop through a ground path.
The problem ofCM unwanted signal is real and somewhat elusive. Because it occurs equally
and in phase on all signal lines with relationship to the reference ground, it becomes evident
within an electronic system only when measured against the reference ground.
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Chapter 2: Electromagnetic Compatibility
Differential Mode (DM)
DM noise affects equipment primarily by corrupting transmitted signals on a balanced circuit.
It can be directly coupled into a circuit (e.g., crosstalk) or derived from a CM signal. DM
noise also can be a result of coupling between two or more pairs inside a balanced cable,
which is an effect referred to as crosstalk. As presented in previous items, twisting the
conductors in pairs can minimize DM interference in these cases. The ground plane is not
involved in this kind of event.
Figure 2.5 compares CM unwanted signal with DM unwanted signal.
Figure 2.5
CM versus DM
----------~~IcM
Line
CM
Neutral
+------
2 IcM
Equipment
ground
Line
.,..__ _ _ _ _ -IDM
DM
Neutral
Equipment
ground
IcM = Common-mode current
I 0 ~1
= Differential-mode current
Sources of Unwanted Signals
Electrical Power Converters
Electrical power converters typically produce both CM and DM unwanted signal. This
generally predominates at the harmonics of the switching frequency, but some wide band
unwanted signal also is produced. Because electrical power converters often are required
within electrical proximity of low signal level circuitry, they can be a major factor in
determining the overall dependability ofthe system involved.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 2: Eledromagnetic Compatibility
Sources of Unwanted Signals, continued
logic Circuits
The logic circuits of telecommunications systems are another source of unwanted signal.
At the switching of logic levels, the local electrical power source can momentarily short to
ground. This introduces unwanted signal directly to both the ground plane and the de power
supply, which may affect the entire electrical system.
Other Internal Unwanted Signal
Internal unwanted signal may be generated from a number of sources that are electrically near
the logic circuitry. Examples include adjacent printed circuit boards or local magnetic sources
(e.g., transformers, mixers). Semiconductor unwanted signals can propagate to logic lines, to
and from digital system clocks, and onto data lines.
Electrical Power line
High-frequency unwanted signal may be coupled on the electrical power line without
affecting the electrical power circuitry. Radiated unwanted signal may be induced on many
components of electronic equipment, especially through unshielded cabling or through an
ineffectively grounded metallic enclosure.
Cabling
The effect of unwanted signal as a result of EMI on telecommunications cabling systems is
the degradation of the transmission channel leading the system to communications errors.
The effect of this interference may be represented by the BER of the system. BER varies
depending on the application implemented in a given cabling system-the higher the
transmission rate, the higher the effect of the interference.
Cables are generally the longest paths between circuit components and modules. They
often provide a loop antenna situation for both radiating and receiving externally generated
unwanted signal fields.
TDMM, 14th edition
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Groundin
Earthing)
General
Proper bonding and grounding (earthing) helps to reduce the effects of EMI. This section
contains several important considerations.
The bonding and grounding (earthing) of buildings, electrical systems, and cabling
infrastructure are as varied and dynamic as the equipment and cabling served within or by
them. fmportant items of consideration when designing a cabling system for EMC are:
• Availability of structural steel within the building.
• Bonding infrastructure for EFs, ERs, and TRs.
• ac grounding (earthing) electrode system design.
• ac equipment grounding (earthing) system design.
• Use of surge protection.
• Use of shielded cable.
• Existing CM or OM disturbance levels.
• Existing or possible sources of EMI.
NOTE: Refer to Chapter 8: Bonding and Grounding (Earthing) for additional resources and
guidance related to bonding, grounding (eatthing), and transient protection.
Ground loops
The term ground loop is often used to describe two parallel paths that have identical
conductive terminations to two separate grounding (earthing) references. Often, but not
always, the earth is one of the parallel paths between grounding (earthing) references.
Ground loops can be a source ofEMI in shielded cabling systems where the earth or
inadequately bonded grounding (earthing) references cause a CM voltage to develop between
the two grounding (earthing) references. This voltage causes CM current to be present on
the cable sheaths (see Figure 2.6). In these cases, it is necessary to provide some kind of
grounding (earthing) systems discrimination or electrical insulation against the ground
loop path.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Ground loops, continued
Figure 2.6
Ground loops in shielded cabling systems
Chassis/cabinet/rack
Chassis/cabinet
Load
Signal source
WA
Telecommunications
room
Ground potential difference (ground loop source)
V9 = Ground loop voltage
V = Voltage source
WA = Work area
NOTES: Shield grounded at the TR.
At the work area, there is a ground path to shield because of the equipment chassis
or cabinet.
At low frequencies, up to about 1 MHz, cable shield can be grounded at one cable
end and provide effective resistance to the effects ofEMI. At higher frequencies,
it is recommended to ground the shield at both cable ends. In these cases, it is
also mandatory to guarantee minimum potential differences between both ground
connections.
There are a number of standards for bonding and grounding (earthing)
(e.g., TIA-607, IEC 60364-4-43) and different requirements, but usually that
difference should not be higher than 1 Vrms to minimize ground loop effects.
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Chapter 2: Electromagnetic Compatibility
Ground loops, continued
It is also important to consider that at higher frequencies, there is a stray capacitive coupling
that tends to complete the ground loop when the cable shield is grounded at one cable end
only (see Figure 2. 7).
Figure 2.7
Ground loop because of stray capacitance at high frequencies
No electrical connection between
cable shield and equipment chassis.
~ood (oat gcoooded)
r-------------------------------~-----
c
..t
Stray capacitance
(high frequency)
Ground potential difference
(ground loop source)
C = Stray capacitance between the cable's shield and the ground plane
V 9 = Ground loop voltage
NOTE: Guidelines for bonding and grounding (earthing) arc contained in Chapter 8: Bonding
and Grounding (Earthing).
Alternating Current (ac) Power
The grounding (earthing) components that arc established for the ac electrical distribution can
be an additional source of EMJ.
At the service entrance, the GEC grounds the electrical power distribution circuit that serves
the ac source for building electrical system and telecommunications.
The equipment grounding conductor contained within ac power circuits provides an
additional grounding (earthing) reference for the connected telecommunications equipment.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Alternating Current (ac) Power, continued
Because of the finite ground plane conductivity, stray ground current through the common
impedance between two ground points creates coupled interference between two circuits or
systems as shown in Figure 2.8.
Figure 2.8
Common impedance coupling interference
Facility A
Facility 8
Signal reference
plane
Signal reference
plane
Voltage difference
between signal references
Stray ground
current
Common impedance
between two points
Unwanted Signal Coupling Mechanism
Figure 2.9 shows two mechanisms for unwanted signal coupling into the receiver: induced
unwanted signal because of external electromagnetic field coupling and conducted unwanted
signal because of external ground loops. Both are equally important. The induced CM
coupling voltage (V en) is a function of the electric field strength and the loop area formed by
a conductor of length that is suspended at an average height above the ground plane.
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Chapter 2: Electromagnetic Compatibility
Unwanted Signal Coupling Mechanism, continued
Figure 2.9
Field-to-cable and ground loop
vcm
is the induced noise
because of external EM field.
Vg is the conducted noise
because of external ground loops.
EM ==
H=
h =
I=
Vcm =
V9 =
Electromagnetic
Magnetic field intensity
Height
Length
Common-mode voltage
Ground loop voltage
The magnitude of the volts in decibels relative to I V can be calculated using the equation for
a circular loop antenna, which is given by:
V em =
2nAE/A
This equation is a good approximation for a loop of any shape that satisfies the inequality:
2nxl'A
<
Where:
x
-
distance around the loop
A
wavelength in meters
A
area of the loop in square meters
E
electric field intensity in volts per meter
The equation shows that installing the cable close to the ground plane can have a significant
effect in reducing the magnitude of induced CM unwanted signal coupling. Changing the
average height from ;::;0.91 m (3 ft) to;::;] 0 l.6 111111 ( 4 in) reduces the unwanted signal coupling
by a factor of 10. 'rhis is equivalent to reducing the field intensity from 3 V/m to 0.3 V/m if
the height was constant.
© 2020 BICSI®
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Chapter 2: Electromagnetic Compatibility
Conduits, Cable Trays, and Raceways
Metallic conduit, whether used as an ac equipment grounding (earthing) conductor or a cable
pathway, is desirable for controlling EMI. Metallic raceways and enclosures should be made
electrically continuous to ensure proper grounding (earthing) of all metallic parts and units to
minimize the accumulation of voltages.
Metallic cable trays, conduits, and raceways can carry some of the ground loop EMT currents
(from 50 Hz to tens of megahertz) throughout several interconnected devices or systems.
Metallic raceways, generally speaking, may be used in computer rooms, factory machine
rooms, and larger sites in which many unshielded cable segments are placed.
Metallic raceways can be used to:
• Reduce CM field to loop EMl pickup as well as emissions at frequencies from 50 Hz up to
IOOMHz.
• Reduce CM crosstalk by increasing wire to ground capacitances.
• Create a reference ground plane.
Metallic cable raceways can be connected directly to the equipment structure or chassis or
by means of a jumper. Such practice will contribute to the reduction of susceptibility and
problems because of CM voltage in large sites. Figure 2.10 shows this behavior.
Figure 2.10
Coupling reduction as function of grounding (earthing) practice
dB
Reduction factor
70
3000
60
1000
50
300
40
.. I I
-
Direct bonding
/
30
~
~
100
:1 ill
Connection by ,;101.6 mm (4 in) wire
20
10
' ",
30
'
10
-
I
3
r--....
0
10kHz
I
'\
1
100kHz
1kHz
10kHz
100 kHz
1kHz
Figure 2.10 shows the reduction of coupling by perforated steel raceway when grounded
directly to the equipment structure (direct bonding curve) and when using an~ I 01.6 mm
(4 in) jumper (connection by ~1 01.6 mm [4 in] jumper wire curve).
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Chapter 2: Electromagnetic Compatibility
Shields
Generally, instrumentation shields should only be grounded at one end. For longer runs and
inter-facility runs, cable shields are generally grounded at each end.
Electromagnetic shielding is a technique employed to reduce or prevent coupling of undesired
radiated electromagnetic energy into a given system to enable it to properly operate in its
electromagnetic environment. It can also be used to minimize the level of radiation from this
given system into its environment.
Electromagnetic shielding is effective in several degrees over a large part of the
electromagnetic spectrum from low frequency and de to the higher microwave frequencies.
Cable Shielding and Shield Effectiveness
Cable shielding is an effective EMI mitigation technique. However, it is important to
emphasize that there are two different approaches to consider:
• Low-frequency noise mitigation
• High-frequency noise mitigation
At lower frequencies, cable twists absorb the major part of the EMI effects.
At higher frequencies, the cable shield absorbs the electromagnetic waves (see Figure 2.11 ).
Figure 2.11
Higher frequency twist decrease
fl
co
u
~
f2
({)
({)
.2
c
f3
0
:;:::;
Q_
'-
0
({)
.0
<(
Twist length (mm [in])
When an electromagnetic wave passes through a medium, its amplitude decreases
exponentially. This effect can be represented by a parameter known as absorption loss.
It occurs because currents induced in the medium are attenuated with conversion of
electromagnetic field energy into thermal energy (heating) of the material.
The parameter that best describes the cable shielding response is the shielding effectiveness.
Measuring the field inside a cable shielding is not easy or feasible. The voltage measured at
either cable end depends on the type of termination and the degree of impedance mismatch at
the cable ends. Thus the definition of shielding effectiveness using the ratio of field strength
on both sides of the shield or the ratio of voltage induced without and with shield is not
convenient.
© 2020 BICSI®
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Chapter 1: Electromagnetic Compatibility
Cable Shielding and Shield Effectiveness, continued
Because of this, the measurement of shielding effectiveness in terms of the cable shield
transfer impedance is often used. The transfer impedance of a cable shield relates the current
that flows on one of the shield surfaces to the current induced on the outer side of a given
surface. The current that flows through the shield may result from the externally incident field
or ground potential difference between the two ends of the cable. Thus the transfer impedance
is a ratio of the voltage induced on the inside surface of the shield to the current flowing on its
outside surface.
Many of the same considerations that apply to balanced twisted-pair cables concerning
unwanted signal coupling apply to screened twisted-pair cables (e.g., F/UTP, U/FTP,
SF /UTP, and S/FTP). These classifications are based on the ISO-IEC 11801-1 cabling
standard. Additional cable classifications may be found in related technical literature.
There are two main differences:
• The effectiveness of the cable shield to reduce external unwanted signal.
• How the cable shield is terminated at the equipment.
The shield effectiveness varies with the:
• Operating frequency.
• Type, thickness, and geometry of the shielding materials.
• Type and quality of the shield terminations.
• Method of grounding (earthing) the shield.
Any leakage through seams, joints, and holes reduces the effectiveness of a shield. It
has been shown that any shield discontinuities (e.g., high-impedance connections due to
improper terminations) can adversely affect the shielding effectiveness.
Considerations about Shield Grounding (Earthing)
The grounding (earthing) of cable screens affects the EMC cable performance. The
termination of shielded/screened cables into connectors requires good connection between
the cable screen and the connector metallic body (or gasket). Grounding (earthing) of cable
shields shall be made using a 360-degree connection avoiding breaches in the conductor
continuity.
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Chapter 2: Electromagnetic Compatibility
Minimizing Electromagnetic Interference (EMI)
Overview
Do not place telecommunications systems next to equipment that can generate EMI.
Keep electrical feeders and branch circuits of interfering equipment separate from
telecommunications systems.
NOTE: Refer to the cable separation section in this chapter for details.
Likely sources of EMI arc heavy-duty electromechanical equipment (e.g., copiers, door
openers, elevator systems, factory equipment, UPS, CRAC units). Cable separation
guidelines of minimizing EMI are available for the ICT distribution designer.
Design of Horizontal Pathways and Spaces
Treat potential sources of EMI as a primary consideration when selecting types of horizontal
cabling and designing the layout of horizontal pathways.
Typical sources of EMI include:
• Electric motors, transformers, and fluorescent lighting that share distribution space with
telecommunications cabling.
• Copiers that share work area space with equipment cords and terminals.
• Electrical power cables serving such equipment.
Avoid EMT by maintaining physical separation between possible sources and the
telecommunications cabling.
Shielded cable has been the traditional choice for buildings with high levels of ambient
EMf (e.g., industrial facilities with large inductive loads). However, performance-enhanced,
balanced twisted-pair cables offer some degree of unwanted signal rejection that makes
shielding unnecessary in most commercial environments. Consult with cable suppliers and
review installation guidelines to determine the level of unwanted signal rejection offered by
various grades of balanced twisted-pair cable.
EMI is an important consideration in the design of pathways and spaces. Providing safe
separation distance from EMI sources for these elements is mandatory to assure applications
performance.
NOTE: Refer to the cable separation section in this chapter for details.
Locate telecommunications pathways and spaces away from sources of EMI (e.g., electrical
power cabling and transformers, RF sources and transmitters, large motors and generators,
induction heaters, arc welders, X-ray equipment, copiers).
The following precautions should be considered to reduce interference from sources of EMf:
• Use grounded metallic pathways to limit inductive unwanted signal coupling between the
telecommunications cabling and potential sources of EMI.
• Use sheathed cables or other branch circuit cable constructions (e.g., taped, twisted,
bundled) that prevent separation of the line, neutral, and grounding (earthing) conductors to
minimize EMI emission from the electrical power conductors. The use of surge protectors
in branch circuits can limit the propagation of electrical surges and associated interference.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Considerations for Electromagnetic Compatibility (EMC) in
Cabling Systems
General Guidelines to Promote Electromagnetic Compatibility (EMC)
General guidelines f()r increased protection against EMI may involve the following:
• Higher balanced twisted-pair cable categories result in better noise rejection response.
• Multiple conductor cable should consist of twisted conductors.
• Multiple conductor cable used f()l· transmission of several individual signals should consist
of balanced twisted-pair signal conductors with different twists.
• Multiple conductor cables should have an overall shield to further improve EMC.
• Terminate unused conductors at both ends or remove them altogether.
• Similar-type signals should be run together and not intermixed (e.g., analog voice with
analog voice, data with data).
• Low-level data transmission lines should not be run parallel to high-level electrical
power lines.
NOTE: Refer to the Cable Separation section in this chapter for details.
• Use localized magnetic barriers when signal lines are found close to switchgear.
• Avoid burying cable below and parallel to high-voltage transmission lines or in areas
subject to high-ground currents.
• Where cables of different signal conditions must cross, crossing should be at a 90 degree
angle.
• Tray and conduit separation spacing should be considered potential problem areas when
designing and maintaining telecommunications cabling systems.
• Source suppression should be considered. Dealing with unwanted signal at the source helps
eliminate major corrective action on cabling systems.
• Use metal conduit f()r electrical-power circuits:
- Premises cabling feeder and branch circuit conductors serving telecommunications
systems should be fully enclosed by metal conduit.
- Each branch circuit should be in a separate conduit or be implemented with shielded
cables.
• Use metal conduit for metallic telecommunications circuits in critical areas (i.e., use
of shielded telecommunications cables in these areas is preferred). Metal conduit is
recommended, especially in the vicinity of electrical power conductors.
• Signal conductors shall not be installed into conduit containing electrical power conductors.
• Maintain an adequate physical separation between potential EMI sources and susceptible
telecommunications equipment.
NOTE: Refer to the Cable Separation section in this chapter for details.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
General Guidelines to Promote Electromagnetic Compatibility (EMC),
continued
• Use surge-protection devices to reduce transients that emanate from inductive devices that
are being switched off. Locate external surge protection devices as close as possible to the
source of the transient.
• Reduce EMI from fluorescent lamps located inside an enclosure. Consider the following
precautions:
Place a shielding grid over the lamp.
Install shielded cable between the lamp and the electrical power switch.
- Install a metal-enclosed electrical power switch.
- Place a filter between the electrical power switch and the electrical power line.
-- Shield the electrical power line cable.
• Use grounded conduits and enclosures. Continuously grounded metal conduit helps to
reduce emission and reception of EM!.
• Minimize proximity to radiating antennae and towers. Electric field strength can
overwhelm sensitive receivers.
• Provide effective bonding between the grounding (earthing) terminals of multiple
surge protection devices placed on both the electrical power and signal circuits of the
telecommunications unit.
• Use optical fiber cables or well-balanced twisted-pair cabling in critical signal circuits.
• Always assume that electrical unwanted signal exists in the proximity of
telecommunications cables and equipment.
Cable Separation
For application performance purposes, power cables should be kept physically separated
from telecommunications cables. Maintain specified distances from possible sources of EMI
exceeding 5 kVA as shown in Table 2.6 and 2.7. For branch circuits of 5 kVA or less, no
additional separation should be necessary.
High levels of noise on power branch circuits (i.e., in the form of surges or other signals with
high-frequency content) is an abnormal and unacceptable condition and should be corrected
or suppressed using line conditioners or surge protection. In situations where these sources or
signals cannot be removed, see ANSIITIA 569-E Telecommunications Pathway and Spaces,
Annex B (informative) Electromagnetic noise reduction guidelines for balanced twisted-pair.
NO'fE: Optical fiber is immune to the effects of EM I.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Cable Separation, continued
Table 2.6
Minimum separation distances from possible sources of EMI exceeding 5 kVA
Condition
Minimum Separation Distance
Unshielded power lines or electrical
equipment in proximity to open or non-metal
pathways.
:::::610 mm (24 in)
Unshielded power lines or electrical
equipment in proximity to a grounded metal
conduit pathway.
:::::305 111111 ( 12 in)
Power lines enclosed in a grounded metal
conduit (or equivalent shielding) in proximity
to a grounded metal conduit pathway.
:::::J52mm (6 in)
Electric motors and transformers
:::::)220 mm (48 in)
Table 2.7
Separation requirements between metallic cabling and specific EMI sources
Source of Disturbance
Minimum Separation
Fluorescent lamps
:::::127 n1111 (5 in)a
Neon lamps
:::::)27 m111 (5 in)"
Mercury vapor lamps
:::::127 mm (5 in)"
High-intensity discharge lamps
:::::)27 111111 (5 in)a
Arc welders
:::::780 mm (31 in)"
Frequency induction heating
:::::991 mm (39 in)"
Hospital equipment
b
Radio transmitter
b
TV transmitter
b
Radar
a The minimum separations may be reduced provided that appropriate cable management systems
are used or product suppliers' guarantees are provided.
b Where product suppliers' guarantees do not exist, analysis shall be performed regarding possible
disturbances (e.g., frequency range, harmonics, transients, bursts, transmitted power).
TDMM, 14th edition
2-38
© 2020 BICSJ®
Chapter 2: Electromagnetic Compatibility
Electromagnetic Interference (EMI) Filters
An electrical power line EMI filter is mandatory in all modern electronics (active equipment)
for conducted emissions or susceptibility aspects or both. A good filter may be able to help
in reducing radiated interference coming in or out through the power line cord. In addition, a
power line filter is useful every time a switching power supply is used. A typical EMI filter is
shown in Figure 2.12.
Figure 2.12
Typical power line filter
Line
To load
L mutual
Phase
Phase
Neutral
Neutral
L mutual
Ground
Ground
C0 = Capacitor for mitigation of DM interference
= Capacitor for mitigation of CM interference
L mutual = Mutual inductance of the inductors used in the filter
C~1
Power line filters are usually designed to mitigate EMls in the line for both CM and OM
disturbances as well (Figure 2.12). The inductors (.L mutua1) connected to the phase and neutral
leads are identical and constructed around ferrite toroids in such a way that fields will be
cancelled, thus allowing high-level currents without saturation of the inductors.
Each inductor will be responsible for CM attenuation. OM interference will not be properly
filtered out by this inductor's array because of inductance unbalance. It is important that the
reactance of these inductors be properly designed in order to minimize part of the differential
disturbance.
The capacitors CD arc responsible for filtering DM interference, while capacitors CM filter CM
interference.
© 2020 BICSI®
2-39
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Data line Filtering-Isolation Transformers
A successful filtering scheme shall provide:
• For the maintenance of signal integrity.
• EfTective attenuation ofhigh-frequency unwanted signals as well as broadband CM
unwanted signal.
Isolation transformers for data signals are quite stringent as they are wideband devices and
shall provide isolation within a wide frequency range. Because of this, these components are
high-cost devices and are implemented in the circuit level of data communications electronics
(e.g., LAN equipment).
The function of these devices is primarily to interrupt the CM ground loop at the receiver or
transmitter end. They offer rejection of CM noise while processing the OM signal without
distortions or other alterations on the signal processed.
The transformer primary-to-secondary capacitance (C 1) tends to close the ground loop across
the barrier. This capacitance leads the system to an unbalance, and some of the CM voltage
is transferred to the secondary of the transformer as DM noise. This transfer is referred to as
mode conversion.
Isolation transformers are commonly used for LAN and other digital communication
applications. Some of these devices provide impedance matching and a balanced-tounbalanced conversion. A good project uses one of the windings connected to the transformer
center tap properly connected to ground. In this case, the two branches of the CM current
are drained to ground thus cancelling the CM noise currents induced into the cable (see
Figure 2.13).
Figure 2.13
Isolation transformer scheme
c12
:--I ~-:
r---------------------------------------------;'-----r---~-----------,
1
Source
Load
- - - - - - - - vc" - - - - - - - -
C12
Ic,1
Vc''
V0 ,.,
=
=
=
=
Transformer primary to secondary capacitance
CM current
CM voltage
DM voltage
TDMM, 14th edition
2-40
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Electromagnetic Compatibility (EMC) by Filtering
Ferrite toroids, beads, and sleeves are efficient components to mitigate EMI problems. These
components can be made in DM (i.e., each wire individually inserted in the ferrite toroid) or
CM type (i.e., one ferrite toroid around the whole bundle of cables). This latter scheme causes
negligible disruption ofthe DM signals in the system.
Ferrites can be used when the alternative cable sheath grounding (earthing) is not
efficient enough for opening the ground loop because of high-frequency interference
(usually> 1 MHz). Ferrites are also indicated when the cable shield currents need to be
reduced without shield interruption.
For DM attenuation, ferrites may be installed on each input lead (susceptible unit) or output
lead (source of EMl) of the component to be filtered. For CM attenuation, a ferrite may be
installed around all wires. To mitigate emission problems, the ferrite shall be installed at the
source cable-end. To mitigate susceptibility issues, the ferrite shall be installed at the input
to the susceptible unit. When using split-type ferrites, air gaps shall be avoided. Figure 2.14
presents samples of ferrite toroids, beads, and sleeves commonly used for EMC compliance.
Figure 2.14
Samples of ferrite toroids, beads, and sleeves
Ferrite toroids
EJ[j
D
~Elu
B
© 2020 BICSI®
A
S
Sleeves
2-41
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Interference Reduction in Shielded Rooms
For many locations, a reduction in the electrical power of the interfering signals by as little
as 10 times can make a dramatic difference in the performance of the telecommunications
system in the room. These reduction levels are routinely accomplished by careful applications
of shielding materials or by the use of a prefabricated shielded room.
Electromagnetic Interference (EMI) and Bandwidth of Balanced Twisted-Pair
Cabling
Applications on high-speed LANs are making greater bandwidth demands on balanced
twisted-pair cabling systems. Today, Gigabit Ethernet ( 1000 Mb/s) LAN and 10 Gigabit
Ethemet (I 0 Gb/s) LAN applications are commonplace.
Cable manufacturers have made gains in the performance ofbalanced twisted-pair cables.
Equipment designers are evaluating more efficient ways of encoding and transmitting
information, which enhances the bit-rate capacity of such cables. However, some
electromagnetic radiation and susceptibility to EMJ continue.
Balance of Twisted-Pair Cabling
The concept of balance is illustrated in Figure 2.15. VcM is the CM unwanted signal voltage
induced in each conductor of a twisted-pair. V, is the conducted unwanted signal because
of the potential difference of the ground (earth) between the workstation and the electronics
(active LAN equipment). For a balanced circuit, the unwanted signal currents :flowing in each
conductor of a pair are equal in magnitude and flow in the same direction, 1111 •
Jnl = Jn2
Equal currents flowing in each half of the primary winding of a well-balanced transformer
produce equal and opposite voltages at the secondary winding, which results in a net
cancellation of the unwanted signal at the input to the receiver. The CM rejection of the
system can be further improved by adding a CM choke in series with the transformer. A
minimum CMRR of 40 dB is desirable for high-quality chokes over the operating frequency
range of interest.
TDMM, 14th edition
2-42
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Balance of Twisted-Pair Cabling, continued
Figure 2.15
Balance concept
J:r~
~---------.....
_ ___,.,..,...I
..
···...
~--nR·
.
~L,.
...
:
_././
For balanced condition: In 1 = In 2
1111 = Noise current in conductor
I 112 = Noise current in conductor 2
15 = Signal current (main current flowing in the circuit)
RL = Load resistance
R5 = Source resistance
Vcr~ = CM voltage
V9 = Ground loop voltage
The concept of balanced twisted-pairs and the calculation of the induced unwanted signal
assume a well-balanced cabling link. In practice, cables and connecting hardware exhibit a
finite unbalance in capacitance, resistance, and inductance between each conductor and the
ground return path.
Depending on the degree of unbalance, a part of the CM unwanted signal is converted to a
DM unwanted signal that passes directly to the input of the receiver. Longitudinal conversion
transfer loss in decibels is a measure of the conversion from CM to OM unwanted signal
because of cabling unbalance.
© 2020 BICSI®
2-43
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Telecommunications Cabli
within Joint-Use Tunnel
The three major components of the electromagnetically induced interference problem relating
to telephone transmission facilities placed in a joint-use utility tunnel with an electrical power
system are:
• Induced electromagnetic fields from the electrical power system.
• Coupling between the electrical power and telecommunications systems.
• The susceptibility of the telecommunications system.
Electrical Power line Influence
The magnitude ofthe electrical power line influence is determined by the magnitude of the:
• Current that propagates over the power cable.
• Physical configuration of the line.
Voltages induced into the telephone plant can create personnel safety hazards and service
problems. The harmonics of power cables produce unwanted signals in circuits and can
interfere with normal equipment operation. This is especially true of electronic equipment
designed to operate at low signal levels. Methods of minimizing the electrical power
system influence include using well-balanced, three-phase systems, and filters to reduce the
harmonics.
Coupling from Mutual Capacitance and Inductance
The coupling from mutual capacitance and mutual inductance between the electrical power
and telephone/telecommunications facility is a function of the:
• Physical separation between the electrical power and telephone/telecommunications
facilities.
• Length of exposure or cables running parallel throughout their pathways.
• Impedance of the retum path for the unbalanced current (e.g., CM return, ground loop).
• Shielding effectiveness of the electrical power and telephone/telecommunications cables.
Reducing Coupling
In a tunnel, using shielding on either facility, where appropriate, can reduce coupling. Place
telephone cables at maximum separation from electrical power cables.
NOTE: Refer to the Cable Separation section in this chapter for details.
TDMM, 14th edition
2-44
© 2020 BICSI®
Chapter 1: Electromagnetic Compatibility
Susceptibility of Circuits and Systems
Circuits and systems are usually connected through cables or cabling systems. These
connections will be exposed to external fields and susceptible to them especially when using
unshielded cables. Conducted interference will be present as well because of ground loops
formed between two or more circuits or systems connected through unshielded or shielded
cables.
Figure 2.16 shows both effects-EM I induced into the circuits or systems because of the
cable connection (i.e., the wire channel will work as an antenna, thereby picking up some
noise) and conducted interference because of ground loop effects.
Figure 2.16
EMI susceptibility of circuits and systems connected through unshielded cables
External fields
I,
Chassis 1
-
Chassis 2
Cable connection
Ground loop
CSI:
I=
v'=
g
V,=
vs =
z, =
zs =
© 2020 BICSI®
Stray capacitance between chassis and ground
Current
Interfering current
Ground loop voltage
Voltage on the load
Source voltage
Load impedance
Source impedence
2-45
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Susceptibility of Circuits and Systems, continued
External fields are responsible for coupling noise into systems when they are connected
through cables. If an external field affects the cable connection, the interfering currents will
be induced in both conductors of the pair (i.e., with similar magnitude in both conductors)
as shown in Figure 2.16. The resulting circuit current (I) will flow in the circuit formed by
the connection of systems I and 2. 'T'he circuitry of both systems has connections to ground
through chassis I and 2. A ground loop will be formed between both systems. The effect of
the ground loop on the overall system's EMI will depend on the difference of the ground
potentials at both cable ends.
If for any reason, the connection to ground is lost at one of the cable ends (as shown in
Figure 2.16 for chassis 2), a stray capacitance will close the loop affecting the overall
system's EMI response. Tn this case, although the lack of the ground loop will be beneficial
for low-frequency coupled noise, the interference will be more significant than in the previous
scenario as the stray capacitance (CsJ between chassis 2 and the ground plane is not well
controlled.
b
ln order to obtain a better response in terms of overall system EMI, it is a good practice to use
balanced shielded cables properly grounded at both cable ends for connection between two
circuits or systems.
Safety considerations require that the chassis or metal enclosures for electrical equipment be
grounded at each end of the cable. In addition, the cable shield needs to be grounded at both
ends so that the shield currents can counteract the effects of electromagnetic unwanted signal
induction from an external field. Unfortunately, this also creates the possibility of conducted
unwanted signal because of ground loop currents.
Figure 2.17 shows the influence of the stray capacitance on the EMI system's performance
for the connection presented in Figure 2.15. In this case, the external field strength in the
environment where the unshielded cable is inserted is 10 V/m. The magnitude of the signal
that propagates over the conductor's pair is 3 V peak-to-peak. At low frequencies the lack
ofthe ground loop (solid line) offers a better response in terms ofEMI immunity shown in
this figure.
TDMM, 14th edition
2-46
© 2020 BICSI®
Chapter 2: Electromagnetic Compatibility
Susceptibility of Circuits and Systems, continued
In this case, the stray capacitance value is 50 pF. At high frequencies (over 100 MHz), the
effect of the ground loop (dashed line) is similar to the effect of the stray capacitance in terms
of system immunity to EM I. It is recommended to ground shielded cabling systems at both
cable ends because of the instability ofthe stray capacitance value along a wide frequency
range (not shown in Figure 2.17).
Figure 2.17
Ground loop and EMI immunity
+30r-----------------------------------------------------~
Field distribution = 10 V/m
--
-
........
Load chassis connected to the ground
- - - Load chassis connected to ground
through a stray capacitance
-170~--------~----------~--------~----------~--------~
10 kHz
100 kHz
1 MHz
10 MHz
100 MHz
1 GHz
EMI = Electromagnetic interference
Two characteristics of the telecommunications circuits that determine susceptibility, or the
extent to which the circuit is adversely affected by inductive fields, are the:
• Amount or presence of shielding provided by the telecommunications cable sheath or by
other grounded conductors.
• Balance of the telecomnmnications circuit.
The worst offenders in terms of unwanted signals are high-frequency transients generated by
starting and stopping machinery (e.g., air compressors, elevator/lift motors) or from switching
electrical power supplies (UPS units). The magnitude of the conducted unwanted signal
currents can impair LAN system performance. These types of problems can be difficult to
diagnose and costly to fix.
A common solution to limit conducted unwanted signal currents is to remove grounds
at various points, which defeats the purpose of using shielded cable for equipment
interconnections. The potential difference between the two grounds shall be no more than
1.0 Vrms to avoid problems with conductive ground loops.
The rms method calculates the consumption or power output of an electronic/electrical
device. RMS power is ultimately the average of an ac waveform, which is the peak voltage
multiplied by 0. 707.
© 2020 BICSI®
2-47
TDMM, 14th edition
Chapter 2: Electromagnetic Compatibility
Recommended longitudinal Balance (Immunity)
It is recommended to use an overall longitudinal balance of 60 dB or greater at low
frequencies (e.g., voice) and 30 dB to 40 dB or greater at high frequencies (e.g., 1-300 MHz).
For a 40 dB immunity, the unbalance of the voltages in each conductor of the cable pair in
regards to the ground plane shall be one percent. Although it is quite easy to obtain 40 dB
immunity at high frequencies, keeping this immunity level along a wide frequency range is
not an easy task.
TDMM, 14th edition
2-48
© 2020 BICSI®
Chapter 3
Telecommunications
Spaces
Chapter 3 provides best practices for the design and
construction of telecommunications spaces, including
ERs, TRs, EFs, and TEs. The chapter discusses
pathway, electrical, fire protection, and HVAC
requirements.
Chapter 3: Telecommunications Spaces
Table of Contents
Telecommunications Spaces .•..................•.••.......... 3-1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Telecommunications Spaces Considerations . . . . . . . . . . . . . . . . . . . . • 3-1
Accessibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Acoustic Noise Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Cable Separation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Ceilings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Codes, Standards, and Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Conduits, Trays, Slots, Sleeves, and Ducts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Entryways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Dust and Static Electricity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Earthquake, Disaster, and Vibration Requirements . . . . . . . . . . . . . . . . . . . . . . . 3-5
Electrical Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Environmental Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Water Ingress Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Floor Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Bonding and Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Safe and Clean Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Sensitive Equipment and Electromagnetic Interference (EMI) . . . . . . . . . . . . . . . 3-10
Size Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Smaller Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Special Size Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Termination Space Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Unacceptable Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
Wall and Rack, Cabinet, or Enclosure Space for Terminations . . . . . . . . . . . . . . . 3-13
Racks, Cabinets, or Enclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
Walls and Wall Linings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
© 2020 BICSI®
3-i
TDMM, 14th edition
Chapter 3: Telecommunications Spaces
Telecommunications Rooms (TRs) and Telecommunications
Enclosures (TEs) . .......
II
•••••••••••••••
II
•••••••••••••••••
3-18
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
Responsibility of the Information and Communications Technology (ICT)
Designer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18
Telecommunications Room (TR) and Telecommunications
Enclosure (TE) Applications ........•.....•.•....•...•....... 3-19
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19
Horizontal Cross-Connects (HCs [Floor Distributors (FDs)]) . . . . . . . . . . . . . . . . 3-19
Backbone Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
Entrance Facilities (EFs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
Telecommunications Room (TR) Design ..............•...•••..• 3-21
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Telecommunications Room (TR) Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Floor Space Served . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Layout Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Telecommunications Room (TR) Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Shallow Room Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
General Requirements for All Telecommunications Enclosures
(TEs)
II
II
B
II
a
II
II
II
II
II
II
II
Ill
II
II
II
II
II
ll
II
II
Iii
II
11
Ill
Ill
11
11
11
11
a
a
11
a
11
11
11
11
11
1!1
11
11
11
11
Iii
II
II
Ill
II
M
B
3-26
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Electrical Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26
Bonding and Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Heating, Ventilation, and Air-Conditioning (HVAC) . . . . . . . . . . . . . . . . . . . . . . . 3-27
Interior Provisioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Size and Spacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Equipment Rooms (ERs} . . . . . . . . . . . . . . . . . .
II
•••••••••••••••••
3-28
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28
Multiple Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
Customer Investment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
TDMM, 14th edition
3-ii
© 2020 BICSI®
Chapter 3: Telecommunications Spaces
Equipment Room (ER) Design • • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-30
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-30
Active Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-30
Cross-Connect Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
Initial Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
locating the Equipment Room (ER) . . . . . . . . . . . . . . . . . . . . . . • • . • . 3-32
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
Major Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
Access to Cable Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Delivery Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Entrance Facility (EF) Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Diverse Telecommunications Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
Supporting Existing Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
Proximity to Electrical Power Service and Electromagnetic Interference (EMI)
Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
Multi-Tenant Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
Unacceptable Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36
Space Allocation and layout . . . . . . • • . . . . . . . . . . . . . . . . . . . . • • . • . 3-37
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37
Providing Adequate Equipment Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37
Determining Size Based on Area Served . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39
Arranging Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39
Working Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
Access Provider (AP) Space Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
Work Area Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
Equipment Installation Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41
Cable Installation and Pathways . . . • . • . . • . . . . . . . . . . • . . . . . . . . . 3-42
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42
Cable Pathways Within the Equipment Room (ER) . . . . . . . . . . . . . . . . . . . . . . . 3-42
Cable Pathways Entering the Equipment Room (ER) . . . . . . . . . . . . . . . . . . . . . 3-44
Electrical Power .
Iii
••
Ill
••
Ill
•••
~~
Ill
Ill
••••
,
...........
Iii
•••••••
Ill
•
Ill
~~
•
3-45
Electrical Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
Coordinating with Other Electrical Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
Maintaining Electrical Power Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
Using Dedicated Branch Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46
Using Dedicated Electrical Power Feeders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46
Power Conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47
Backup Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47
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Chapter 3: Telecommunications Spaces
Heating, Ventilation, and Air-Conditioning (HVAC) Environmental
Control ......... ~~ .. ~~ ~ ~ . . . . . . . . . . . . .
II
••••••••••
II
••••••••••
3-48
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48
Heating, Ventilation, and Air-Conditioning (HVAC) Operation . . . . . . . . . . . . . . . 3-48
Environmental Control Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-49
Miscellaneous Considerations ....••••............•.••••...... 3-50
Maintaining Valid Warranties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Design Approval, Buildout, and final Inspection .....••••••...... 3-50
Reviewing the Design with the Customer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Planning the Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Installation Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-51
Installing the Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-51
Inspecting the Equipment Room (ER) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-51
Entrance facilities (Efs) ........•............•.•••..•....... 3-52
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52
Required Service Entrances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52
Entrance Media Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53
Service Entrance Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53
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Chapter 3: Telecommunications Spaces
Figures
Figure 3.1
Typical cabinet and rack mounting hole spacing arrangements ....... 3-15
Figure 3.2
Rack unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Figure 3.3
Space considerations when sizing a telecommunications space ....... 3-17
Figure 3.4
Typical TR layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Figure 3.5
Typical sleeve/conduit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
Figure 3.6
Typical shallow room layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25
Figure 3. 7
Typical AP ER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
Figure 3.8
Typical ER layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38
Tables
Table 3.1
Size guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Table 3.2
Smaller buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Table 3.3
Allocating termination space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
Table 3.4
Layout considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
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Chapter 3: Telecommunications Spaces
Telecommunications
Introduction
The scope of this chapter is the design and construction of telecommunications spaces.
Telecommunications spaces are the rooms and areas where telecommunications cabling
systems are terminated, cross connected, and interconnected to installed telecommunications
equipment. Bonding and grounding (earthing), fires topping, and labeling of
telecommunications infrastructure also occur in telecommunications spaces.
Although the scope is limited only to the telecommunications aspect of building design, this
chapter influences the design and architectural aspects of other building services.
'l'his chapter also impacts space allocation within the building. Other codes, standards, and
regulations may apply to the design and installation of telecommunications cabling systems
as they pertain to telecommunications spaces.
This chapter defines guidelines for the following telecommunications spaces:
• TEs
• TRs
• ERs
• EFs
All considerations that apply to TRs, ERs, and EFs are grouped under the heading
Telecommunications Spaces Considerations. Any considerations that apply to specific spaces
are grouped under the subheading for that specific telecommunications space. TEs have a
section in this chapter dedicated to this type of space.
Telecommunications Spaces Considerations
Accessibility
Accessibility requirements for space considerations include the following:
• 'felecommunications spaces that are intended to serve multiple tenants should be located
in common spaces that should be accessible through a common corridor or outside door.
These forms of access will limit interruption to the building tenants. Locating this type of
space in one tenant's space may be a burden to one tenant when service is required for the
other tenants.
• Telecommunications spaces that are intended to serve multiple tenants may also present
security concerns for some tenants who may not wish to share access to their network
equipment.
Entry into any locked telecommunications space, area, or room shall be available to the
owner's maintenance personnel, building management, or a common key/access control
credential. Authorization shall be provided to each tenant.
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Chapter 3: Telecommunications Spaces
Acoustic Noise levels
Acoustic noise levels in telecommunications spaces should be kept to a minimum by locating
noise-generating equipment (e.g., photocopy equipment, high-speed printers, mechanical
equipment) outside the telecommunications spaces.
NOTE: Hearing protection may be required.
The TCT systems distribution designer should consult with building managers or owners for
suitability. Sound barriers should be specified if sources of unacceptable noise cannot be
located outside the telecommunications spaces.
Administration
The ICT distribution designer should:
• Keep records and other documentation pertaining to the design, layout, and specifications
of telecommunications pathways, spaces, and cabling systems in accordance with
Chapter I 0: Telecommunications Administration.
• Establish a complete and systematic means of identifying elements of the
telecommunications infrastructure.
• Establish procedures for the ongoing administration of the telecommunications system as
changes occur.
• Provide all pertinent documentation on administration to on-site personnel representing the
building owner or agent when the installation is completed.
• Ensure that all telecommunications spaces have appropriate signs to identity the space and
are included within the security plan of the building.
• Use color-coded cross-connect fields to facilitate cabling administration. Well-organized
color coding enables identifying backbone and horizontal cabling quickly and helps to
ensure that cabling topology requirements are met. Accepted methods for color coding
cross-connect fields include the use of colored backboards, connections, covers, or labels.
NOTES: These color assignments are used only to identify cross-connect fields and are
considered to be independent of media type and telecommunications services
(e.g., voice, data). The assignments do not apply to protection apparatus or other
elements of the cabling system for which other (proprietary) color schemes may
be used.
For recommended color codes for cross-connect fields, refer to the Color Codes
table in Chapter l 0: Telecommunications Administration.
Cable Separation
Telecommunications cables should be separated from possible sources of EMl and from
possible RFL For safety purposes, power cables shall be separated from telecommunications
cables.
NOTE: For complete design and installation guidelines concerning EMI and RFI, including
equipment or typical system power factors and minimum cable separation, refer to
Chapter 2: Electromagnetic Compatibility.
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Chapter 3: Telecommunications Spaces
Ceilings
The general requirements for ceilings in telecommunications spaces include the following:
• The minimum ceiling height should be ~2.4 m (8 ft)AFF. Consideration should be given to
having a ~3 m (1 0 ft) height.
• When a ceiling distribution system is used, telecommunications spaces should be designed
with adequate pathways or openings through walls and other obstructions into the
accessible ceiling space.
• Alterations of structural steel or structural concrete require the approval of a structural
engineer.
• To permit maximum flexibility and accessibility of cabling pathways, a suspended ceiling
is not recommended in telecommunications spaces unless it is part of the air cooling
strategy. If a suspended ceiling is specified it should be a grid system with removable metal
or other non-fibrous tiles no larger than ~o.6 m x 0.6 m (2 ft x 2 ft).
• Equipment may require additional ceiling clearance, depending upon the manufacturer's
specifications. Excessive equipment and rack, cabinet, or enclosure height should be
avoided because it may require special lighting and wider working clearances (e.g., taller
than ~2.4 m [8 ft] AFF).
• 'fhe ceiling finish should minimize dust and be light colored to enhance the room lighting.
Clearances
The following clearances should be provided for equipment and cross-connect fields in
telecommunications spaces:
•
Provide~ 1 m
(3.28 ft) of clear, unobstructed space for the installation and maintenance of
all cabling and equipment mounted on walls, racks, cabinets, or enclosure.
• It may not be possible to achieve ~1 m (3.28 ft) of clear, unobstructed space when cabling
is mounted below access floors or above ceilings. In such cases, provide as much clear,
unobstructed space as possible.
• Provide at least~ 150 mm (6 in) depth off the wall for wall-mounted equipment.
• For racks and cabinets, the working clearance shall take into account the depth of rackmounted equipment as well as wall-mounted equipment and hardware.
• Provide minimum working clearance (front and rear)
equipment.
• In corners, a minimum side clearance
of~300
of~l
m (3.23 ft) from installed
nun (12 in) is recommended.
• Consult the manufacturer's documentation and local codes for specific requirements.
• The ICT distribution designer should always consider adequate clear space in the area of
cabling terminations and equipment connections for safety considerations.
NOTE: ln many cases, equipment and connecting hardware may extend beyond racks,
cabinets, enclosures, and backboards. It is important to note that the clearance is
measured from the outermost surface of these devices rather than trom the mounting
surface of the rack, cabinet, enclosure, or backboard.
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Chapter 3: Telecommunications Spaces
Codes, Standards, and Regulations
All applicable codes, standards, and regulations during the design, construction, and use
of telecommunications spaces should be observed. See Appendix A: Codes, Standards,
Regulations, and Organizations for additional details.
Conduits, Trays, Slots, Sleeves, and Ducts
If possible, sleeves, slots, or conduits should be located such that cable terminations on the
wall can be performed from left to right. Trays and conduits located within the ceiling should
protrude into the room a distance of::::::25.4 mm (1 in) to ::::::51 mm (2 in) without a bend and
above ::::::2.4 m (8 tt) high. The type and location of the cross-connect fields may influence the
optimal placement of pathways.
IMPORTANT: The location of structural and facility systems elements shall be identified
prior to locating penetrations.
Slot/sleeve systems should be located in places where pulling and termination will be easy to
achieve.
Where vertical and horizontal offsets are required, bend radius requirements and service loop
guidelines should be considered.
Sleeves and slots shall not be lett open after cable installation. All sleeves and slots should
be firestopped in accordance with the AHJ and project requirements. See Chapter 7: Firestop
Systems for detailed information on firestopping of cabling pathways.
The size and number of conduits or sleeves used for backbone pathways depend on the
usable floor space served by the backbone distribution system. However, at least four
::::::I 03 mm (4 trade size) sleeves are recommended to serve a TR, ER, or EF. See Chapter 4:
Backbone Distribution Systems to determine the exact size and number of conduits or sleeves
required for backbone pathways.
Multiple telecommunications spaces on the same floor shall be interconnected with a
minimum oftwo ::::::103 mm (4 trade size) conduits or a pathway that provides equivalent
capacity. For horizontal pathways, use the requirements for conduits, trays, and ducts
provided in Chapter 5: Horizontal Distribution Systems.
IMPORfAN'r: The ICT designer shall coordinate all of the above requirements concerning
backbone pathways with the applicable stakeholders (e.g., client, other trades
and disciplines, AHJs).
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Chapter 3: Telecommunications Spaces
Entryways
The following guidelines should be used when installing doors in telecommunications spaces:
• Entryways that are planned for use during equipment delivery shall be fully opening
(e.g., to 180 degrees if local building codes permit). Doors shall be a minimum of
:::::0.91 m (3 ft) wide. If it is anticipated that large equipment will be delivered, a double
door ::::: l. 83 m (6 ft) wide should be provided. All doors shall have access control.
• Door sweeps should be considered instead of thresholds.
NOTE: Doors that open outward provide additional usable space and reduce constraints on
telecommunications spaces layout but are sometimes prohibited by building codes.
• Doors shall have the same fire rating as the room.
• Access to the telecommunications space should not be constrained when completed.
• Access should allow for future equipment changes.
• Avoid multiple entrances from areas of the building that may compromise security or
provide access to unauthorized personnel. Additional doors that are not intended for
equipment delivery should have lockable door hardware sets that meet building code
requirements.
• For double doors, where center posts are required, the center posts should be removable.
Where doors cannot be opened fully, they should be removable.
Dust and Static Electricity
Dust and static electricity should be avoided by:
• Installing antistatic floor tile bonded to ground using manufacturer-recommended
hardware.
• Installing grounded floor tiles and mats bonded to ground using manufacturerrecommended hardware.
IMPORTANT: Carpet is not recommended.
• The use of antistatic coatings on concrete floors.
• Placing active printers outside oftelecommunications spaces.
• Treating all surfaces to minimize dust.
NOTE: The building contractor should be consulted for recommendations on preferred
treatments, paints, or other coatings that may be applied to minimize dust and static
electricity.
Earthquake, Disaster, and Vibration Requirements
Structural reinforcement and extra environmental protection should be included in the
design of telecommunications spaces where seismic construction regulations apply. The ICT
distribution designer should understand the seismic zone where the building is located. A
qualified professional engineer should be consulted where appropriate.
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Chapter 3: Telecommunications Spaces
Electrical Power
Telecommunications spaces shall be equipped to provide adequate electrical power for the
maximum design load for all equipment specified. Recommendations include:
• Each telecommunications space should have its own dedicated electrical distribution panel.
• Branch circuits to lT equipment should not have GFCI (earth leakage type) breakers unless
this is a specific requirement of the AHJ.
• A minimum of two non-switched ac receptacles for equipment power, each on individual
branch circuits rated at minimum 16 A at 220-240 V or 20 A at 120 V based on countryspecific requirements.
• Separate duplex or quad convenience receptacles (e.g., for tools, field test instruments):
Located at least;:::; 152 111111 ( 6 in) AFF.
Placed at ;::::1.83 m (6ft) intervals around perimeter walls.
• Coordinating light switch locations for easy access upon entry.
• Identifying convenience receptacles.
• Providing a UPS from a local or central UPS where available.
• Considerations for redundant power systems and power quality.
• Providing emergency power with automatic switchover capability to the
telecommunications space.
NOTE: See Chapter 9: Power Distribution for additional details.
Environmental Control
HVAC should:
• Maintain a continuous and dedicated environmental control (i.e., 24 hours per day, 365
days per year). If emergency power is available, the ICT distribution designer should
consider connecting it to the HVAC system that serves the telecommunications space.
• Maintain a positive pressure with a minimum of one air change per hour in the
telecommunications space. More stringent requirements may apply based on the equipment
needs in the telecommunications space.
• Satisfy applicable building codes.
• Maintain a temperature and humidity level to the intake of IT equipment as recommended
by the manufacturer of the specified equipment and ASH RAE or other relevant standards.
If parameters are exceeded, an alarm should result.
The total power load should be converted to heat load units and coordinated with the
mechanical engineer:
Power (W) x 3.412 =BTU [calorie]/hr
The TCT designer shall determine the heat load (BTU [calorie]/hour) of all equipment
installed within the space. If heat loads are not available for individual pieces of equipment,
the designer will need to determine the true power load of all equipment installed within the
space.
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Chapter 3: Telecommunications Spaces
fire Protection
A fire alarm should be provided in a telecommunications space according to applicable codes.
Portable fire extinguishers with appropriate ratings shall be provided per AHJ.
The focus of the fire protection system should be on prevention, early warning, and
containment. The type of fire suppression system designed for telecommunications spaces
shall be coordinated with the owner and AHJ.
The recommendations for fire protection include:
• Coordinating the layout of fire protection systems with the equipment layout to avoid
obstructing sprinklers, access to the alarm, or other protective measures.
• Considering emergency exit routes and adhering to applicable codes.
• The methods, materials, and considerations for reestablishing the integrity of fire-rated
architectural structures and assemblies (e.g., walls, floors, ceilings) required by building
codes shall be observed when these barriers are penetrated by cables, pathways
(e.g., conduit or trays), or other penetrating elements.
• Consulting with the AHJ concerning local firestop requirements. The TCT distribution
designer is encouraged to work directly with firestop material manufacturers to provide
appropriate drawings or written specifications in order to meet the AHJ requirements.
• Using qualified personnel to install approved firestop systems.
• Rejecting fire-rated tape wrap.
• Installing wire cages to prevent accidental operation of sprinkler heads.
• Installing drainage troughs and positioning sprinkler heads for wet pipe systems to protect
equipment trom any leakage that may occur.
• Using pre-action sprinkler systems to minimize water damage.
• Covering wall linings with two coats of fire-retardant white paint (or other light-colored
finish).
• Using clean agent fire suppression systems.
• Using early warning smoke sampling systems.
• Providing a system that signals authorities or monitoring services when an event occurs.
NOTE: For further information on fire protection and firestopping of cabling pathways,
see Wall and Wall Linings in this chapter and Chapter 7: Firestop Systems for fllliher
details.
© 2020 BICSI®
TDMM, 14th edition
Chapter 3: Telecommunications Spaces
Water Ingress Prevention
Telecommunications spaces should be located above any threat of water ingress
(e.g., flooding).
When locating telecommunications spaces where a threat of water ingress is unavoidable,
design rack elevations so that active equipment and telecommunications components are
as high off the floor as possible. Consider the addition of a sump pump system which will
operate on emergency power if commercial power fails.
Locations (e.g., restrooms, kitchens) that are below or adjacent to areas of potential water
ingress should be avoided.
Liquid carrying pipes (e.g., water, waste, steam) shall not be routed through, above, or in the
walls encompassing the telecommunications space.
Where water ingress risks are unavoidable, consider a water leak detection system with
alarms to a manned location.
Floor loading
When considering tloor loading, the ICT distribution designer shall:
• Determine what floor loading will be needed for the equipment
(e.g., ~2.4 kPa [50.13 lbf/ft2]).
• Check with the building architect for actual floor-loading rating.
• Obtain the services of a qualified structural engineer ifrated floor loading is less than the
actual determined requirement.
Bonding and Grounding (Earthing)
All equipment and cable shields shall be properly bonded to the space's telecommunications
bonding and grounding (earthing) infrastructure.
The following points should be considered:
• If multiple equipment grounding (earthing) or intersystem grounding (earthing) is
necessary, a copper busbar shall be provided.
• The SP shall be consulted to determine any special grounding (earthing) requirements that
may apply if an SP furnishes backbone cable.
NOTE: See Chapter 8: Bonding and Grounding (Earthing) for detailed grounding
requirements as they relate to safety codes, APs, SPs, and equipment manufacturers.
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Chapter 3: Telecommunications Spaces
lighting
Considerations for lighting in telecommunications spaces include:
• Locating light switches near the entrance(s) to the telecommunications space. Dimmers and
vacancy sensors are not recommended.
• Coordinating the lighting layout with the equipment layout (especially overhead cable
trays) to ensure that lighting is not obstructed.
• Providing electrical power for the lighting, which should not come from the same circuits
as the telecommunications equipment (see Using Dedicated Electrical Power Feeders in
this chapter).
• Placing at least one light or set of lights on normal power and one light or set of lights on
emergency power.
• Using a light-colored finish on walls, floors, and cabinets to enhance room lighting.
• Providing a minimum of ;::;SOO lx (46 foot-candles) of lighting in the horizontal plane
and ;::;200 lx (18.6 foot-candles) in the vertical plane, measured ;::;Im (3.28 ft) above the
finished floor in the middle of all aisles between cabinets and racks.
• Locating light fixtures a minimum of;::;2.6 m (8.5 ft) AFF when possible and coordinating
closely with the rack, cabinet, or enclosure placements.
• Using emergency lighting as required by applicable codes. Emergency lighting should
ensure that the loss of power to normal lights will not hamper an emergency exit from the
telecommunications space and will assist personnel that may need to gain access to critical
infrastructure (e.g., the power distribution panel).
location
All telecommunications spaces should be located in areas that are best suited to serve the
occupants of a floor, building, or campus.
The following should be observed when locating the spaces:
• Telecommunications spaces in multi-floor buildings should be aligned vertically (stacked).
• Telecommunications spaces built using one or more load-bearing walls reduces the
possibility of relocating the telecommunications spaces if the floor or building is expanded
or altered in the future.
• Telecommunications spaces should be located in areas that are dedicated
to telecommunications use. Equipment that is not related to the support of
telecommunications spaces (e.g., piping, duct work, distribution of building power) should
not be located in or pass through a telecommunications space.
• Telecommunications spaces shall not be shared with building or custodial services. For
example, sinks and cleaning materials (e.g., mops, buckets, solvents) shall not be located or
stored in a telecommunications space.
• Telecommunications spaces should be located as near as possible to the center of the area
to which they will provide connectivity, in order to minimize cable lengths.
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Chapter 3: Telecommunications Spaces
Safe and Clean Environment
Telecommunications spaces:
• Are frequently visited by technicians and shall be safely accessible.
• Should be kept free of any storage material or other obstructions that could prevent
technicians from performing their duties or create a fire hazard.
Security
Appropriate physical security measures should be considered when selecting or designing
telecommunications spaces.
The necessity of protecting the physical assets located in telecommunications spaces can
require a range of solutions, from simple mechanical access controls (e.g., locks and keys) to
sophisticated electronic security systems (e.g., IDS). A variety of design options are available.
Digital video surveillance, with recording and analytics to detect suspicious behavior, should
also be considered.
NOTE: Refer to Chapter 17: Electronic Safety and Security and Chapter 18: Data
Centers for the security design options and recommendations that can be used to
protect telecommunications spaces.
Sensitive Equipment and Electromagnetic Interference (EMI)
Sensitive electronic equipment should not be located next to electrically noisy equipment
that can cause EML. Electrical feeders and branch circuits should be kept away from sensitive
equipment and its associated telecommunications cabling and equipment.
Likely sources of EMl include heavy-duty electromechanical equipment (e.g., electrical
power transformers, copiers, door openers, elevator systems, factory equipment).
In cases where EMJ sources cannot be avoided, means to mitigate the adverse effects of EMl
on cabling and equipment are available (e.g., high-performance copper cabling, shielding,
optical fiber).
NOTE: See Chapter 2: Electromagnetic Compatibility.
Size Guidelines
Telecommunications spaces vary in size, depending on their function and the size of the
usable floor space they serve.
Telecommunications space sizing guidelines for horizontal cabling distribution are based on
distributing telecommunications services to one individual work area per ;:::;9.3 m 2 (1 00 ftl) of
usable floor space.
Additional space may be required, depending on the owner's needs. Some spaces may house
multiple types of systems. Architects, building owners, or managers should be consulted
during the space planning process.
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Chapter 3: Telecommunications Spaces
Size Guidelines, continued
Minimum telecommunications space sizes are shown in Table 3 .1.
Table 3.1
Size guidelines
Then the Interior Dimensions of the
Room Shall Be at Least ...
lfthe Serving Area Is ...
;::::465 m 2 (5000 ft 2) or less
;::::3 111 ( 10 ft) by ;::::2.4 m (8 ft). (See note
below.)
Larger than ;::::465 m 2 and less than or
equal to ;::::743 m 2 (>5000 ft 2 to 8000 ftl)
;::::3m (10ft) by ;::::2.74111 (9ft).
Larger than ;::::743m2 and less than or
equal to ;::::929m 2 (>8000 ft 2 to 10,000 ft 2 )
;::::3m (10ft) by ;::::3.4 m (11ft).
NOTE: The size of;:::;J m (10ft) by ;::::2.4 m (8ft) is specified here to allow a center rack,
cabinet, or enclosure configuration.
Smaller Buildings
In smaller buildings, less space is required to serve the telecommunications distribution needs
of the occupants (see Table 3.2).
Table 3.2
Smaller buildings
If the Building ls Smaller Than ...
It May Be Served By ...
;::::465 m 2 (5000 ft 2)
Shallow rooms (see Figure 3.6).
2
;::::93 m (I 000 ft 2 )
• Wall cabinets.
• Self-contained cabinets.
• Enclosed cabinets.
NOTES: Installation of active equipment in shallow or walk-in rooms is not recommended
because many types of equipment require environmental controls and a depth of at
least ;:::;J m (3.28 ft).
All utility cabinets shall be AHJ approved and marked in accordance with applicable
electrical codes.
Special Size Considerations
For existing installations and building retrofits, it is recognized that the preceding
telecommunications spaces size guidelines may not be possible in all cases.
If, for reasons beyond the control of the JCT distribution designer, the minimum size
guidelines cannot be met, ;::::1.2 m (4ft) depth by ;::::].83 m (6ft) width by ;::::2.6 m (8.5 ft)
height (inside dimensions) of the telecommunications space should be provided with sliding
or double ;::::914 mm (36 in) doors for every 240, 4-pair cable terminations served.
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Chapter 3: Telecommunications Spaces
Size Guidelines, continued
The minimum dimensions provided above may not be adequate if special telecommunications
services (e.g., CATV, ACS), BAS functions, or provisions for future growth are needed.
NOTE: Refer to Chapter 14: Building Automation Systems, Chapter 17: Electronic Safety
and Security, and Chapter 19: Health Care for design options and equipment that may
be installed in telecommunications spaces.
Termination Space Allocation
Use the guidelines in Table 3.3 to estimate space guidelines when planning for cable
terminations. These guidelines are based on having two-sided access (front and rear) to the
connecting hardware. (See the notes following the table for additional information.)
The space allocations in Table 3.3 are provided only as a basis for estimation.
Table 3.3
Allocating termination space
For ...
Allocate ...
Balanced twisted-pair
;::::2580 mm 2 ( 4 in 2) for each 4-pair circuit to be patched or
cross connected (allows tor two 4-pair cable terminations and
two 4-pair modular patch connections per circuit).
Optical fiber
;::::1290 mm 2 (2 in 2) tor each optical fiber core/strand to be
patched or cross-connected (allows for two cable/patch
connections per channel). This space allocation is also
appropriate for coaxial cable.
NOTES: For balanced twisted-pair cross-connections using insulation displacement
contact termination blocks and jumpers, cross-connect field density may be
considerably greater.
When cabling requires surge protection, the recommended space allocation is two
to four times larger than the space above for cross-connections.
These space allocations do not include cable runs to and from the cross-connect fields. Up
to 20 percent more space may be required for proper routing of cables, jumpers, equipment
cords, and patch cords.
The space actually required depends on the:
• Mounting scheme used (e.g., wall or rack, cabinet, enclosure).
• Type and layout of connecting hardware used.
• Active equipment.
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Chapter 3: Telecommunications Spaces
Unacceptable Materials
The telecommunications space shall not be used to store any materials that are corrosive,
combustible, or explosive.
Examples of these prohibited materials include:
• Cleaning chemicals (e.g., acid, ammonia, chlorine).
• Office and computer supplies (e.g., paper, cardboard, copier/printer fluids).
• Grounds-keeping chemicals (e.g., fertilizers, insecticides, ice melt).
• Materials that could generate combustible dust or other airborne particles.
• Petroleum, natural gas, or other fuels.
• Hazardous materials (e.g., asbestos).
A telecommunications space shall be clear of all items not related to its function. The
telecommunications space and other spaces that share the same HVAC systems shall be
isolated Jrom contaminants and pollutants that could affect the operation, reliability, or
integrity of the telecommunications equipment or cabling.
The means used to protect telecommunications systems from contaminants include:
• Vapor barriers.
• Positive room pressure.
• Absolute filters.
WaH and Rack, Cabinet, or Enclosure Space for Terminations
Whenever possible, space should be located for terminations of each type of cable on one
continuous wall or in a rack, cabinet, or enclosure.
The ICT designer should provide plan and elevation drawings showing the location of all
critical equipment and connectivity, including:
• Cabinets and racks.
• Cable management.
• Cable pathways.
• Patch panels.
• Alarm panels.
• Shelving.
• Bonding (grounding).
• Other facility systems.
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Chapter 3: Telecommunications Spaces
Wall and Rack, Cabinet, or Enclosure Space for Terminations, continued
The lCT distribution designer should plan for:
• A minimum clear space of;::;l27 mm (5 in) above and below the top and bottom ofthe
connecting hardware for cable management.
• Additional rack, cabinet, enclosure, or backboard space for routing cables, patch cords,
equipment cords, or cross-connect jumpers (cables may also be routed behind the
connecting hardware).
NOTES: See Telecommunications Room (TR) Design and Equipment Room (ER) Design in
this chapter for additional information on special size considerations and
termination space for various cable types.
To allow access, do not mount termination hardware closer than;::; 152 mm (6 in) to
any corner.
See Layout Considerations in this chapter for recommended side clearance in
corners.
Narrow sidewalls should be reserved for:
• Splice cases.
• Miscellaneous items.
Cross-connect fields, patch panels, and active equipment in the telecommunications space
shall be placed to allow cross-connections and interconnections via jumpers, patch cords, and
equipment cords whose lengths per channel do not exceed:
• ;::;5 m ( 16.5 ft) for patch cords, equipment cords, or jumpers in the HC (FD).
• ;::;IO m (33ft) total for patch cords/jumpers, equipment cords connected to the HC (FD),
plus the work area equipment cord.
• ;::;20m (66ft) for patch cords or jumpers that serve MC (CD) or IC (BD).
NOTE: See Chapter 4: Backbone Distribution Systems and Chapter 5: Horizontal
Distribution Systems for additional information.
Racks, Cabinets, or Enclosures
Racks, cabinets, or enclosures are recommended to have a height of ;::;2.1 m (7 ft) and have
a rail size and top flange width of;::;483 mm (19 in) (see Figure 3.1). Mounting hole spacing
should confonn to EIA/ECA-310-E, Cabinets, Racks, Panels, and Associated Equipment,
and provide two equipment mounting holes spaced ;::;32 nun (1.26 in) apart, with a
;::;12.7 mm (0.50 in) space between the top of one set of mounting holes and the bottom of the
next set. Each set ofthree holes creates a space of;::;49 mm (1.75 in) and is called an RU
(see Figure 3.2). Many racks, cabinets, and enclosures provide an additional equipment
mounting hole centered between the top and bottom equipment mounting holes, which
provides additional mounting flexibility without deviating from the basic EIA/ECA-31 0-E
pattern.
NOTE: Some mounting systen1s require rack widths greater than ;::;483 mm ( 19 in).
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Chapter 3: Telecommunications Spaces
Racks, Cabinets, or Enclosures, continued
Figure 3.1
Typical cabinet and rack mounting hole spacing arrangements
Threaded holes
#12-24 or #10-32
r
lU (1. 75")
J2U(3.5")
13U
(5 25")
_j '""'
Figure 3.2
Rack unit
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Chapter 3: Telecommunications Spaces
Racks, Cabinets, or Enclosures, continued
In rooms with limited floor space, the use of taller equipment racks, cabinets, or enclosures
should be considered to help compensate for the inability to add another rack, cabinet, or
enclosure.
When additional width is recommended or required for special equipment (e.g., dual
vertically positioned tower-type server shelves), racks, cabinets, or enclosures that have a
width of;-:::584 mm (23 in) should be considered.
When placing equipment rack, a vertical cable management panel should be placed on at least
one side of the rack or between the rack and the room wall. Cable management panels need to
be sized to allow the placement and management of contained cables and patch cords. When
multiple racks are used, vertical cable management panels should be placed between each
rack, with additional panels at each end. Cabinets and enclosures should have self-contained
or integrated vertical cable management.
ln addition to vertical cable management, horizontal cable management panels may be
utilized to manage the patch cords between the patch panel and the equipment. The ratio
of one RU patch panel to one RU horizontal cable manager plus one additional RU cable
manager is recommended.
When angled patch panels are installed, the use of vertical cable management is
recommended.
All unused rack and cabinet spaces should have blank panels installed.
Walls and Wall linings
Unless otherwise specified by the AHJ, telecommunications spaces should have a 2-hour fire
rating. This will help ensure compliance with survivability requirements for ERRCS should
the system be required in the building.
Walls should:
• Be fire-rated as required by the applicable AHJ and industry standards.
• Be light in color to reflect light.
• Have at least two walls lined with AC grade or better, void-free plywood, ;-:::2.4 m (8ft) high
with a minimum thickness of;::; 19 mm (0. 75 in).
• Be kiln-dried to maximum moisture content of 15 percent to reduce warping.
Mount plywood ::::;200 mm (8 in) AFF to provide greater usability and minimize possible
damage in the event of water ingress. Install plywood with the grade A surface exposed.
Flush hardware and supports should be used to firmly secure plywood to the wall. The
strength and placement of the hardware should be sufficient to handle the total anticipated
load (e.g., static and dynamic) and mounting of cabling and cable management components
(see Figure 3.3).
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Chapter 3: Telecommunications Spaces
Walls and Wall linings, continued
NOTE: Plywood should be painted on all sides and within cutout areas with two coats of
fire-retardant light-colored paint. Fire-rated plywood may be required in some
facilities. Alternately, the plywood may be covered with drywall to satisfy building
code requirements in some areas; however, this should be avoided if possible and
verified with the AHJ prior to installation.
Figure 3.3
Space considerations when sizing a telecommunications space
,--------------11' 7"-------------
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CD
0
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0
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QJ
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0"
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0
E
E
ro
ro
s
s
36" clearance
required by code for
working space
© 2020 BICSI®
14' 10"
E
36" clearance
required by code for
working space
TDMM, 14th edition
Chapter 3: Telecommunications Spaces
Telecommunications Rooms (TRs) and Telecommunications
Enclosures (TEs)
Overview
TRs and TEs differ from ERs and EFs in that they are generally considered to be floor-serving
or tenant-serving (e.g., as opposed to building- or campus-serving) spaces that provide a
connection point between backbone and horizontal infrastructures.
TR and 'l'E design should consider incorporation of other building information systems in
addition to traditional voice and data needs (e.g., CATV, wireless networks, alarms, security,
audio, other building signaling systems).
TRs and TEs provide an environmentally suitable and secure area for installing:
• Cables.
• Cross-connects.
• Connecting hardware.
• Telecommunications equipment.
The design of TRs and TEs depends on the:
• Size of the building.
• Floor space served.
• Occupant needs.
• 'T'elecommunications service used.
• Future requirements.
• Number and type of cables being served from the space.
BICST specifies a telecommunications infrastructure that distributes telecommunications
services to each individual work area.
Central to this function are the TR and TE that allow, in a structured way, the intercom1ection
of work areas on the same floor or to other floors via the backbone cabling.
Responsibility of the Information and Communications Technology (ICT)
Designer
The ICT designer must understand the design and customer requirements of the building.
This is accomplished by meeting with building stakeholders. ICT designers should optimize
the ability of the telecommunications spaces to accommodate change and avoid limitations by
vendor requirements.
The designer should review all documentation including manufacturer's specifications and
operating manuals to determine all applicable system requirements.
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Chapter 3: Telecommunications Spaces
Telecommunications Room (TR) and Telecommunications
Enclosure (TE) Applications
Overview
A TR is an enclosed architectural space for housing telecommunications equipment, cable
terminations, and cross-connect cabling.
ATE is a case or housing for telecommunications equipment, cable terminations, and crossconnect cabling.
At least one TR or ER serves every building with a minimum of one TR per Jloor. A TR may
serve only one tenant, or it may be used to serve multiple tenants. ATE is generally applied
as a subset to the traditional TR. This case or housing is smaller than a TR and is typically
used to service a specific area of a building Jloor.
There is no maximum number ofTRs or TEs that may be provided within a building. The
'fR and the TEare the recognized connection points between the backbone and horizontal
pathways.
The types of cabling facilities that may be housed in the TRs include:
• HCs (FDs).
• ICs (BDs).
• MCs (COs).
'TT;;s typically serve a relatively small number of users on a floor, and as such, the type of
cabling facility that may be housed in TEs is typically limited to HCs (FDs).
Horizontal Cross-Connects (HCs [Floor Distributors (FDs)])
The facility used to make connections to the horizontal cabling in the TR and TE is the HC
(FD). The HC (FD) provides access to the horizontal cabling from the backbone cabling and
the telecommunications equipment.
To serve this function, the TR and 'fE shall provide facilities (e.g., space and mounting
provisions) for horizontal and backbone cable terminations and for the use of patch cords,
jumpers, or both.
NOTE: See Chapter 5: Horizontal Distribution Systems for detailed information on
horizontal cabling.
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Chapter 3: Telecommunications Spaces
Backbone Cross-Connects
Although the primary function of the TR and TE is to house the HC (FD), it may also contain:
• ICs (BDs).
• MCs (CDs).
• Passive cabling components (e.g., connecting hardware, patch cords, jumpers).
• Active devices that are served by the backbone cabling.
NOTE: See Chapter 4: Backbone Distribution Systems for detailed information on
backbone cabling.
Entrance Facilities (Efs)
The EF should be sized based on the number and type of cables entering the space.
An EF may also contain a TR.
An EF that houses a TR in this space:
• Shall provide for passive cabling components (e.g., connecting hardware, protection
apparatus, patch cords, jumpers).
• May also include active devices that are required to interconnect the campus EF to the
building telecommunications cabling.
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Chapter 3: Telecommunications Spaces
Telecommunications Room (TR) Design
Overview
A properly designed TR includes an HC (FO) that provides a floor-serving distribution
facility for horizontal cabling.
This cross-connect is capable of providing horizontal cabling connections to floor-serving
telecommunications equipment and backbone cables that connect to:
• Other TRs and TEs.
• ERs.
• EFs.
The TR should be provisioned to house telecommunications equipment.
NOTES: Providing separate TRs located in or directly accessible to each tenant's leased
space should be considered. For additional information on TR accessibility, see
Location in this chapter.
In some cases, it may be necessary to combine the building and floor-serving
functions of the ER and TR in one room. Instances where the two may be combined
include smaller buildings (i.e., less than ;:::502m2 [5400 ft 2]) and those with limited
space for distribution facilities.
Telecommunications Room (TR) Guidelines
Floor Space Served
There shall be at least one TR or ER per t1oor.
Multiple rooms are required if the cable length between the HC (FD) and the
telecommunications outlet location, including slack, exceeds ;:::90 m (295ft). If the usable
t1oor space to be served exceeds ;:::929 m 2 (I 0,000 ft 2), consider additional TRs.
For TRs that serve areas with an office density of less than one work area per ;:::9.3 m 2
( 100 ft 2 ) of usable floor space, a TR may serve larger areas, provided the horizontal cable
length requirements are met.
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Chapter 3: Telecommunications Spaces
Telecommunications Room (TR) Guidelines, continued
layout Considerations
When designing the layout of a TR, consider the issues presented in Table 3.4.
Table 3.4
Layout considerations
If...
Then ...
A substantial portion of the TR is
dedicated to backbone cable
distribution
Include space for splicing and ladder racking.
Special telecommunications services
are provided
Allow additional space for cross-connect
equipment.
More than one tenant is served from
the same TR
Provide clear separation and identification of
each tenant's equipment and terminations.
An E.:F is housed at the same location
Include space for cabling protection, grounding
(earthing) enclosures, and splice cases.
EF = Entrance facility
TR = Telecommunications room
Telecommunications Room (TR) Diagram
Figure 3.4 shows a typical layout for a full-size TR, suitable for a maximum of 480, 4-pair
cable terminations.
The drawing illustrates architectural, mechanical, electrical, and telecommunications
requirements on a single plan view perspective for purposes of showing coordination issues.
Actual design documents will typically separate requirements by discipline.
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Chapter 3: Telecommunications Spaces
Telecommunications Room (TR) Diagram, continued
Figure 3.4
Typical TR layout
Pathways
i:-------
with firestop
~3m
(10 ft)-------""1
i§VAC
supply or
n :«2.6 m (8.5 ft)
minimum
~-········-·········--
+-+--------+-P
20 amp twist-lock
:«2.6 m (8.5 ft) AFF
""2.6 m
(8.5 ft) AFF '-.
1
Backboard
for other
low-voltage
system
:«2.4 m
(8 ft)
TR interconnecting
conduit, 78 mm
(3 trade size)
minimum with
pathways with
firestops
l
19 mm (0.75 in)
plywood backboard
""2.6 m
(8.5 ft) AFF "-.
\
(i) L~I§BI
ED p
HVAC
supply or
return ""2.6 m (8.5 ft)
AFF minimum
Pathways
with firestop
~
(i)
AFF
EDP
HVAC
SBB
TR
= Telecommunications outlet/connector
= Thermostat
= Above finished floor
=
=
=
=
© 2020 BICSI®
Electrical distribution panel
Heating, ventilation, and air-conditioning
Secondary bonding busbar
Telecommunications room
3-23
TDMM, 14th edition
Chapter 3: Telecommunications Spaces
Telecommunications Room (TR) Diagram, continued
Figure 3.5 shows a typical sleeve/conduit through a TR floor.
Figure 3.5
Typical sleeve/conduit
r
Sleeve through wall
pathways with firestops
103 mm ( 4 trade size)
19 mm (0. 75 in)
plywood backboard
J
I
103 mm (4 trade size)
inside diameter
l_-
:f
I
1
~xtended
.
~ 75 mm (3 m)
Sleeve or conduit pathways
with firestops
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Chapter 3: Telecommunications Spaces
Shallow Room Diagram
A shallow room is defined as an enclosed space for housing cable terminations, cross-connect
cabling, and telecommunications equipment.
Figure 3.6 shows a typical layout for a shallow room. The layout may be better suited for
splicing than terminations. Sleeve placement shall be considered when using a shallow room
so that there is vertical alignment with TRs above and below when used in this manner.
Figure 3.6
Typical shallow room layout
19 mm (0. 75 in)
plywood backboard
Sleeves or conduits with
pathways with firestops
~2.6
Sleeves or conduits
with pathways
with firestops
III/
\
\
m (8.5 ft)
\
\
'
© 2020 BICSI®
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TDMM, 14th edition
Chapter 3: Telecommunications Spaces
General Requirements for All Telecommunications Enclosures
(TEs)
Overview
ATE is simply a case or housing for telecommunications equipment, cable terminations, and
cross-connect cabling.
The TE is dedicated to the telecommunications function and related support facilities. The
TE may contain access points for wireless services. Although TEs serve much in the same
capacity as that of a TR, a minimum of one TR must be located on each floor.
Access
TEs shall be accessible. Access toTEs should be controlled against unauthorized access (e.g.,
with a lock and key held by the facility or property manager).
Door
The TE door(s) may be hinged or removable. If the door is hinged, mount the enclosure so
that the door swings open a minimum of 90 degrees or otherwise provides unobstructed
access to the inside of the enclosure.
The door should remain open until manually closed. Provide and maintain sufficient working
space for a technician to gain ready and safe access to the TE.
Electrical Power
A minimum of one dedicated, non-switched duplex receptacle should be available for
equipment power in each TE.
If standby power is available, automatic switch over of power should be provided. Where
appropriate, a UPS should be considered.
NOTE: See Chapter 9: Power Distribution for additional information.
Fire Protection
Fire protection of the TEs, if required, shall be provided per applicable code. If sprinklers are
required within the area of the TE, the heads should be specified with a protective cover to
prevent accidental actuation.
ATE should not be installed where subject to leakage from fire suppression sprinklers.
Drainage troughs shall be placed under the sprinkler pipes to prevent leakage onto the
enclosure.
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Chapter 3: Telecommunications Spaces
Bonding and Grounding (Earthing)
If the enclosure consists of metallic components, the enclosure shall be bonded to the
telecommunications bonding and grounding (earthing) infrastructure.
NOTE: See Chapter 8: Bonding and Grounding (Earthing) for additional information.
Heating, Ventilation, and Air-Conditioning (HVAC)
When active devices (e.g., heat-producing equipment) are present, a suftlcient number
of air changes should be provided to dissipate the heat from all sources. Active device
manufacturers should be consulted for guidelines. Audible noise created by the equipment
within the TE should not adversely affect the productivity or satisfaction of nearby workers.
Interior Provisioning
To facilitate the mounting of hardware, mounting holes should be installed, where
appropriate, within the enclosure. Optionally, the TE may be equipped with a plywood
backboard that is secured to the back or side of the interior portion of the enclosure.
lighting
Light, as measured within the TE, should be a minimum of::::-;538 lux (50 foot-candles).
Lighting design should seek to minimize shadows within the TE.
location
The TE should not be installed in furniture systems unless that unit of furniture is
permanently secured to the building structure.
Pathways
Pathways shall not pass through TEs. Cables that enter and exit the TE are to be protected
from sheath abrasion and conductor deformation by means of grommets, bushings, and
suitable management hardware.
Size and Spacing
ATE should serve an area not greater than ::::-;334 m 2 (3600 ft2 ). Size the TE to accommodate
immediate requirements and foreseeable growth. Sufficient space within the TE should be
provided to ensure compliance with cable bend radii limitations.
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Chapter 3: Telecommunications Spaces
Equipment Rooms (ERs)
Overview
An ER is an environmentally controlled centralized space for telecommunications equipment
that usually houses an MC (CD) or IC (BD).
ERs differ from TRs in that ERs are generally considered to serve a building, campus, tenant,
or SP, whereas TRs serve a floor area of a building. ERs may be connected to backbone
pathways that run both within and between buildings.
ERs:
• Contain terminations, interconnections, and cross-connections for telecommunications
distribution cabling.
• May include work space for telecommunications personnel.
NOTE: If work space is planned for telecommunications personnel, it should be limited to
those who work within the ER. Since electronic equipment is sensitive to dust, any
dust or dirt tracked into the room needs to be kept at a minimum.
• Are built and laid out according to stringent requirements because of the nature, cost, size,
and complexity of the equipment involved.
When designing ERs, incorporating building information systems other than the traditional
voice and data systems (e.g., CATV, fire alarm, life safety facility protection, ACS, BAS,
security, audio, other building signaling systems) should be considered.
NOTE: For further information about these systems, see Chapter 13: Audiovisual Systems,
Chapter 14: Building Automation Systems, and Chapter 17: Electronic Safety and
Security.
Although an ER usually serves an entire building, many building designs use more than one
ER in order to provide one or more of the following:
• Separate facilities for different types of equipment and services
• Redundant facilities and disaster recovery strategies
• A separate facility for each tenant in a multi-tenant building
• A separate facility for each AP and SP
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Chapter 3: Telecommunications Spaces
Multiple functions
ln some cases, an ER may also:
• Contain the EF (for campus backbone, APs, or both).
• Serve as a TR.
NOTE: An ER may provide any or all of the functions of a TR or an EF.
Customer Investment
An ER is a centralized facility that houses telecommunications equipment that is essential to
the daily activities of the building's occupants.
Therefore, an ER shall be:
• Versatile-An ER shall be designed to accommodate both current and future applications.
Its design shall have provisions for growth and the ability to go through numerous
equipment replacements and upgrades during its life.
• Reliable-An ER shall be designed for ease of operation and maintenance with minimal
service disruptions.
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Chapter 3: Telecommunications Spaces
Equipment Room (ER) Design
Overview
An ER may contain some or all of the following:
• Active equipment
• Cross-connect facilities
• BAS or other building system equipment
An initial assessment is a critical first step in designing an ER because of the broad scope
of designs possible, the wide range of functions the room may serve, and the complex
relationships between the room's contents.
Active Equipment
The types of apparatus housed in ERs vary greatly in size, purpose, and function. These
apparatus can include:
• Power conditioning and backup systems.
• Environmental controls.
• Telecommunications equipment.
• Fire suppression or smoke/heat detection systems.
• ACS and IDS.
Typically, the telecommunications equipment serves the voice, data, and CATV
telecommunications needs of the building's occupants.
One or more of the following may provide voice and data service on the customer's premises:
• CO based service using direct lines, carrier equipment, or remote switching (for both voice
and data)
• Key telephone systems and PBXs
• Adjuncts (e.g., voice mail, automatic call distribution, call accounting)
• VoiP systems
• PON equipment
• Centralized processing systems (e.g., mainframe and minicomputers using WANs, LANs,
and other proprietary terminal communications interfaces)
• Servers, switches, and active electronics for LANs
Other telecommunications services in the ER may include those for power-limited services.
Such services may include:
• CATV.
• Life safety facility protection.
• ACS and IDS.
• BAS.
• Audio.
• Other building signaling systems.
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Cross-Connect facilities
Telecommunications cables are terminated in the ER at a cross-connect. For backbone
distribution, the ER may contain an IC (BD) or an MC (CD).
NOTE: Because it may serve any or all of the functions of a TR, an ER may also contain an
HC (FD) that serves a portion of the building.
In addition to terminating the cables, cross-connect facilities provide a means for
connecting the cabling subsystems (e.g., backbone and horizontal) to each other and to
telecommunications equipment.
NOTE: For further information about recommended connection schemes using crossconnections and interconnections, see Chapter 5: Horizontal Distribution Systems.
The following should be considered:
• Horizontal and backbone cables shall be permanently terminated on connecting hardware
that is securely mounted. All connections between the horizontal and backbone subsystems
shall be cross-connections.
• In order to facilitate changes and minimize the lengths of patch cords, jumpers, and
equipment cables, terminate cables of the same type adjacent to each other. If multiple
types of cables are used, they should be installed in distinct areas within the ER.
• The most common types of backbone cabling/media are:
-- Balanced twisted-pair.
Multimode optical fiber.
Singlemode optical fiber.
Coaxial.
NOTES: For other recognized types of backbone cable, see Chapter 4: Backbone
Distribution Systems.
For infonnation on color coding for cross-connect facilities and space requirements for
various types of cabling, see Chapter I 0: Telecommunications Administration.
Initial Assessment
The design and specifications for an ER shall be based on detailed information about the site,
including:
• Customer requirements.
• Telecommunications pathway locations.
• AP and SP requirements.
• Environment/facility conditions and resources.
• Building requirements.
The design of a new ER shall begin with an initial assessment that considers each of the
factors listed above. The ICT distribution designer shall consider the information gathered
in the initial assessment at all stages of the design project along with the guidelines and
requirements of the applicable standards and this manual.
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Locating the Equipment Room (ER)
Overview
Selecting a suitable location is the most basic step in planning an ER. ln selecting a location,
be aware of the spaces immediately adjacent to (e.g., beside, below, above) the ER.
In many cases, the location will be dictated by the customer, property manager, or building
owner (who shall allocate space for the ER) or by system and facility requirements. In
general, the amount of space allocated for the ER is dictated by the:
• Size and variety of systems to be installed.
• Size of the area that the room will serve.
Even when the choice of locations is constrained by factors that the ICT distribution designer
cannot control, the guidelines provided in this section need to be implemented as fully as
possible.
Major factors
The major factors that shall be considered when choosing the location for an ER include:
• Space required for the equipment.
• Provisions f(x future expansion.
• Access for delivery and installation of large equipment and cables.
• Building facilities that serve and are served by the ER.
• AP requirements.
• Proximity to electrical service and mechanical equipment.
• Sources of EML
• Relationship to service entrances for telecommunications and electrical power.
• Access and proximity to telecommunications cabling pathways (e.g., installations in which
the ER serves multiple backbones).
• Floor loading.
NOTE: For further details about factors that affect location selection, see Unacceptable
Locations in this chapter.
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Access to Cable Pathways
The ER shall have access to the backbone pathways. Place the ER at a location that
minimizes the:
• Size and length of the backbone cables, especially in multiple-backbone situations.
• Length of horizontal cable (i.e., in situations where the ER contains an HC [FD]).
Examples of this type of location include the:
• Tenth floor of a 20-floor, single-tenant office building.
• Center of a large, single-floor building.
• Center of a large campus.
Layouts for cabling pathways are generally determined after the location of ERs, EFs, and
TRs are established.
Delivery Access
The ICT distribution designer should locate the ER so that it is accessible for the delivery of
large equipment throughout its useful life.
The following should be considered when choosing its location and designing its layout:
• Accessibility
• Size of doors
• Weight capacity offloors
• Corridors
• Elevators or hoists for vertical transport of equipment
• Loading docks
• Any other access routes to the ER
• Any potential ditliculties in scheduling the use of these routes and facilities for moving
large equipment during installation or future changes
Entrance facility (Ef) Requirements
In cases where the functions of the EF are combined with the functions of the ER in the
same space, the room may house equipment that is owned and maintained by APs (e.g., a
network interface). In these cases, requirements specified by the AP shall be considered when
designing the AP ER.
Before designing an AP ER that will house equipment owned by an AP, the ICT distribution
designer should obtain a written list of the AP's requirements.
For example, APs may require that electronic equipment (e.g., protection, transmission,
remote switching) be located in a separate room secured by locked access. If a separate AP
space is required, it should be in or adjacent to the EF and may require a mesh partition or
locked cabinet. A space of at least ;:::;1.2 m by ;:::;1.83 m (4ft by 6ft) should be allocated for
each AP (see Figure 3.7).
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Entrance Facility (EF) Requirements, continued
Figure 3.7
Typical AP ER
Plywood backboard
receptacle
Light fixture
Location of rack
or cabinet
Architectural_/
assembly or
wire mesh
Ught
swit:~/
I
\
\
\
AP
EF
HVAC
SBB
SP
=
=
=
=
=
''
Convenience:._}
receptacle
' '- ---~
/
-------
Access provider
Entrance facility
Heating, ventilation, and air-conditioning
Secondary bonding busbar
Service provider
Diverse Telecommunications Systems
A properly designed telecommunications infrastructure (e.g., spaces, pathways, cabling) is
capable of supporting a broad range of telecommunications applications. For this reason, the
common and tenant ER should be capable of accommodating all the telecommunications
services required by the tenant, building, or campus.
To provide this function, the ICT distribution designer should consider the diverse needs of
these systems so that the functions of all telecommunications systems that serve the same
area may be combined into one space.
In cases where a data center is provided as a separate facility, the room should be adjacent to
the ER. This will help to simplify the installation of the large volume of cable required to link
the two rooms.
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Supporting Existing Systems
In some cases, an ER design shall allow for the support or reuse of existing
telecommunications equipment or cabling. Although the selection of an ER location
may be influenced by the location of existing telecommunications facilities, give careful
consideration to the long-term benefits of a properly located and designed facility that is
capable of meeting present and future needs.
The lCT distribution designer should weigh these benefits against the potentially shorttenn cost savings of adding to existing facilities that may restrict growth and lead to higher
ongoing maintenance costs as telecommunications needs evolve.
Proximity to Electrical Power Service and Electromagnetic Interference (EMI)
Sources
When it is practical, minimize the length of the electrical power feeds from the electrical
service entrance to the ER.
Having these facilities in close proximity will:
• Aid in designing an optimal bonding and grounding (earthing) arrangement.
• Minimize bonding and grounding (earthing) disturbances.
When planning an ER location, the ICT distribution designer should consider potential
sources of EMI and RFI. Locate the ER far enough away from sources of EMI and RFI to
reduce interference with the telecommunications cabling.
Pay special attention to EMl and RFI from:
• Electrical power supply transformers.
• Motors.
• Generators.
• X-ray or photo copying equipment.
• Radio transmitters.
• Radar transmitters.
• Induction heating devices.
• Arc welding equipment.
For complete design and installation guidelines concerning EMI and RFl, including
equipment or system typical power factors and minimum cabling separation distances from
possible EMI and RFI sources, refer to Chapter 2: Electromagnetic Compatibility.
Multi-Tenant Buildings
Whenever possible, each tenant in a multi-tenant building should have a dedicated ER. If a
dedicated ER is not possible for each tenant, lockable cabinet(s) should be specified for each
tenant. When multiple tenants share ERs, the building owner or agent shall control access.
Access control guidelines will need to be discussed with all tenants who share the space to
mitigate security concerns.
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Unacceptable locations
The ICT distribution designer should not locate ERs in any place that may be subject to:
• Water or steam infiltration.
• Humidity trom nearby water or steam.
• Heat (e.g., direct sunlight).
• Any other corrosive atmospheric or adverse environmental conditions.
Shared use of ER space with other building facilities shall be avoided. Locations that are
unsatisfactory for ERs include space in or adjacent to:
• Mechanical rooms.
• Washrooms.
• Custodial closets.
• Storage rooms.
• Loading docks.
• Shear walls.
• Any area that contains sources of excessive EMI, hydraulic equipment, and other heavy
machinery.
• Spaces that cannot be traversed by pathways (e.g., elevator shafts, stairs, pipe chases, duct
shafts, multistory atriums).
The ICT distribution designer should avoid using the ER as a means of accessing the spaces
listed above or using the spaces listed above to access the ER.
NOTE: For additional restrictions on the use of ERs for storage, see Unacceptable Materials
in this chapter.
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Space Allocation and Layout
Overview
The layout of the major telecommunications equipment in an ER shall facilitate the routing
of electrical power and telecommunications cabling. The TCT distribution designer shall
carefully evaluate the location of each piece of equipment and the space allocated for it. It is
recommended that the ICT designer review all equipment, media, and connectors and ensure
compatibility within the design.
Additionally, the ICT designer shall coordinate with all stakeholders (e.g., client, other trades
and disciplines) to resolve any potential or actual conflicts.
Providing Adequate Equipment Space
An ER shall provide enough space for:
• All planned equipment.
• Access to the equipment for maintenance and administration.
• Growth.
The ER shall meet the space requirements specified by the equipment provider(s). If the ER
will contain equipment that serves different telecommunications applications (e.g., voice,
data), each application's space and layout requirements shall be taken into account.
Manufacturers often provide suggested system and cabling layouts. The ICT distribution
designer should consider all manufacturers' guidelines when designing the ER layout. A
space of at least :::-;J m by :::-;4. 9 m ( l 0 ft by 16 ft) should be allocated.
Even if the customer does not anticipate growth, the ER should include adequate space to
support equipment changes with minimal disruption. Many equipment changes could take
place during the life of any ER.
In addition to space for telecommunications equipment and cabling, an ER shall include
space for environmental control equipment, power distribution/conditioners, and UPS
systems that may be installed (see Figure 3.8).
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Providing Adequate Equipment Space, continued
Figure 3.8
Typical ER layout
»~6.1 Ill
UPS DP
I
B
(20 ft)
EDP
I
I
IT
I
I
HVAC
-
Light fixtures
(8.5 ft) AFF
»~2.6 Ill
Row of bays or cabinets
»~4 .6 Ill
I
I
I
I
I
I
(15 ft)
TRi nterconnecting
conduits
I
l
LaJLaJ
19 mm (0. 75 in)
plywood (fireproof)
Light fixtures
m (8.5 ft) AFF
»~2.6
/
()()()
l
Firestop
pathways
PBB
-
I
r::1
R
Door sized to
accommodate
equipment sizes
\ 19 mm (0.75 in) plywood
TR interconnecting
conduits
A=
AFF =
EDP =
HVAC =
PBB =
TR =
UPS=
UPS DP =
Outlets
Above finished floor
Electrical distribution panel
Heating, ventilation, and air-conditioning
Primary bonding busbar
Telecommunications room
Uninterruptible power supply
UPS distribution panel
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Determining Size Based on Area Served
When the lCT distribution designer does not know what specific equipment will be used in an
ER, the designer can use the amount of floor space that the room will serve to determine the
minimum size of the ER.
The following steps can be used to determine the minimum size of an ER.
Step
Task
Divide the amount of usable lloor space by :::::9.3 m 2 ( 100 ft 2 ) to determine
the number of individual work areas that the ER will serve through both
backbone and horizontal cabling.
NOTES: Usable floor space includes the building area used by occupants in
their normal daily work functions. For planning purposes, this
should include hallways but not other common areas of the
building. If the usable floor space is unknown, deduct 20 percent of
the total floor area to estimate the usable floor space.
An area of:::::9.3 m 2 (100 ff) is an industry average used to
calculate work areas. If work areas are smaller, the size of the ER
shall be increased accordingly.
2
Divide the amount of total floor space by :::::23.2 m 2 (250 ft 2) to determine
the number of BAS devices that the ER will serve through both backbone
and horizontal cabling.
3
Multiply the number of work areas to be served by :::::0.07 m 2 (0.75 ft2 ) and
the number of BAS devices to be served by :::::0.023 m 2 (0.25 ft 2) to
determine the ER size.
If there are fewer than 200 work areas, the ER shall be no less than :::::]5m 2 (160 ft2). For
special-use buildings (e.g., hospitals, hotels), ER size requirements may vary.
Arranging Equipment
An ER shall have a layout that is easy to use and maintain. All aspects of the layout should be
llexible enough for equipment to be changed without structural renovation. Planned growth in
the areas served by the ER shall be considered in the initial design.
The ease with which equipment can be serviced, upgraded, or replaced should also be
considered when planning the layout of equipment and cross-connects. The layout of the
ER should be designed to allow future system changes with a minimum of labor and service
disruption. Under optimum conditions, a system cutover should be invisible to the users and
other systems supported by the ER.
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Arranging Equipment, continued
When designing equipment layouts, the ICT distribution designer should review
all manutftcturer's documentation for all specifications, including the:
• Weight of equipment.
• Physical dimensions.
• Number of RUs.
• Clearances.
• Distance limitations between cabinets.
• Power requirements (e.g., ac, de).
• Cable management (e.g., vertical, horizontal).
• Installation requirements.
Client equipment space requirements should also be obtained.
NOTE: Chapter 18: Data Centers may also be useful in the design of large ERs.
Working Clearances
Applicable codes generally require a minimum working clearance around equipment. This
minimum is determined by a number of factors, including the:
• Voltage.
• Exposure of live parts.
• Equipment orientation.
• AHJ.
• Location of grounded parts.
Typical equipment cabinets require ::::oO. 9 m 2 ( 10 ft2) of t1oor area and an additional
::::o0.9 m 2 (1 0 ft 2) of area for working clearance. The ICT distribution designer should check
the manufacturer's working clearance requirements when planning installations.
Access Provider (AP) Space Requirements
lf equipment or cable terminations that are owned or maintained by an AP shall be located in
the ER, determine the location and amount of space that is required. Include this AP space in
the ER design.
Work Area Space
Most ERs include work areas (e.g., desk space) for system administrators. Some ERs include
workstation, display, and printout areas. Also, customers may need to integrate business
functions related to information management (e.g., report collation, forms processing) within
or adjacent to the ER. The space and layout of the ER shall accommodate such functions.
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Work Area Space, continued
NOTES: Telecommunications cabling that serves work areas within the ER shall comply with
horizontal cabling requirements as explained in Chapter 5: Horizontal Distribution
Systems.
Because of combustibles, dust, and other variables that create fire hazards,
customers should avoid using ERs as work space for employees not related to
telecommunications system administration.
Equipment Installation Methods
The following equipment mounting and installation methods should be considered when
designing an ER:
• Like connecting hardware, most network and telephone equipment are available with
wall-mounting options. In this method, a void-free plywood backboard treated with a
nonconductive, fire-resistant covering is permanently attached to the wall. The backboard
allows for simple, flexible equipment installation using wood screws through mounting
holes in the equipment and connecting hardware.
• Determine the wall area, depth, and clearances required trom equipment specifications,
including cable routing area and allowance for growth. Backboard installation shall be
complete before equipment installation begins.
• Floor-standing racks, cabinets, or enclosures are typical of medium- to large-sized crossconnect installations where space efficiency is needed or where equipment is specifically
designed for rack, cabinet, or enclosure mounting. Determine the floor area and clearance
footprints required from equipment specifications (e.g., allowing for change out or growth).
Locate racks, cabinets, and enclosures so that electrical and telecommunications cable
routing can be done efficiently from underftoor or overhead distribution systems (e.g., cable
trays). Bonding and grounding (earthing) equipment and hardware should be provided and
installed according to the manufacturer's instructions.
• Cabinets typically are used for large electronic telecommunications equipment (e.g., voice
and data switching systems, computer equipment). Cabinets may be used to provide:
Physical and security protection.
Electromagnetic enclosure.
Dust and contaminant protection.
• Determine the floor area and clearance footprints required from equipment specifications
(allowing for change out or growth).
• Locate the cabinets so that electrical and telecommunications cables can be efficiently
routed from raised floor or overhead distribution systems (e.g., cable trays).
• Secure the cabinets to the building structure and bond according to the manufacturer's
instructions. (Manufacturers may specify special bonding requirements for cabinets,
including insulating hardware.)
• Some types of network equipment (e.g., computers) are sometimes located on the system
administrator's desktop. Although desktop placement may be suitable for some equipment,
ICT distribution designers should avoid this practice for telecommunications equipment
that is used to perform network functions or serve the user community (e.g., LAN servers).
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Chapter 3: Telecommunications Spaces
Cable Installation and Pathways
Overview
The ER is the location for housing the MC (CD) for connections between:
• Equipment and the backbone.
• Backbone runs that extend to ICs (BDs) or HCs (FDs).
Many ERs also contain an HC (FD) to serve work areas on the same floor and may have EFs
for campus backbone runs and APs.
When laying out cable pathways entering the ER or within the ER, ensure that the layout:
• Avoids cable congestion.
• Allows access to the cables.
• Provides adequate storage of cable slack.
• Minimizes cable stress (e.g., tension, twisting, bending).
Refer to Chapter 5: Horizontal Distribution Systems for detailed information on:
• Pathways used for campus backbone, building backbone, and horizontal cables.
• Cross-connect layout and space allocation.
• Cabling installation practices.
Cable Pathways Within the Equipment Room (ER)
The cable pathways described in this section are commonly used for routing bulk
telecommunications cables within the ER. Although they are also used for cable distribution
between facilities, these pathways are particularly well-suited for cable distribution within
ERs because of their capacity for handling bulk cables and their ability to accommodate
change.
The following cable pathways commonly are used to route bulk cables within an ER:
• Cable tray or ladder rack systems commonly are used for routing equipment and backbone
cables between cross-connects, equipment, and backbone pathways. Install trays or ladder
racks overhead along the equipment rows, leading to the cross-connects. Coordinate tray
locations with lighting, air-handling systems, and fire suppression systems so that fully
loaded trays will not obstruct or impede their operation.
Cable trays shall be installed in accordance with applicable codes and standards. A
minimum of;::;2Q3 n11n (8 in) access headroom is required, with :.:::;305 mm (12 in)
recommended.
• Access floors commonly are used to route equipment cables to cross-connects in large
ERs. Access floor systems (sometimes called "raised floors") are frequently used for
telecommunications cabling when the ER serves multiple applications (e.g., both computer
and telephone equipment). When cooling or return air is provided under access flooring, all
cabling must be plenum rated.
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Cable Pathways Within the Equipment Room (ER), continued
NOTE: When using the space under raised floors for routing communications, ground, or
ac power cables, careful consideration needs to be given to its design as this could
create air flow dams when the space is also to be used as an HVAC system air supply
or return plenum.
• Consideration should be given to physical cable management in an access floor
environment. High-performance cabling (e.g., optical fiber, balanced twisted-pair, coaxial)
shall be properly installed and managed to avoid transmission degradation. For this reason,
the use of cable trays or other suitable means for cable management and protection under
access flooring is strongly recommended. Care should be taken not to obstruct airflow.
• Optical fiber cables specified to be placed under an access floor or overhead should be
placed into a separate trough system specifically designed as an optical fiber cabling
pathway in order to protect the cabling from damage.
• Strapping, lashing, and hooking involve a wide variety of small hardware for mounting and
securing telecommunications cable to backboards, walls, ceilings, racks, and other fixed
objects. These are usually low-cost methods that typically are not suitable as the primary
means of cable distribution within ERs because of their limited bulk cable capacity and
their inability to accommodate change.
• The ICT distribution designer shall avoid specifying hardware that provides marginal
physical support or has the potential to damage the cable. The ICT distribution designer
shall:
- Verify that hardware ratings are adequate for the cables' weight.
- Ensure spacing that will prevent cables from sagging or buckling.
- Use hardware only for its listed purpose.
Provide support transitioning between pathways.
- Verify cable capacity.
Verify that the AHJ approves of the hardware.
If ER walls are needed for such cable routing, allocate suitable wall space and allow for
growth. Cable routing systems that mount on walls, racks, cabinets, or enclosures are useful
for providing cable management between connecting hardware and the primary distribution
pathways (e.g., overhead cable trays) within the ER. Follow the manufacturers' instructions
for cable routing to and from connecting hardware.
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Cable Pathways Entering the Equipment Room (ER)
The following types of cable pathways arc commonly used for telecommunications cables
that enter and exit an ER:
• Slots and sleeves-These are the most common methods for routing cable through building
walls and floors. Sleeves are preferred because they are easier to firestop. A minimum of
four I 03 mm (4 trade size) sleeves with at least one spare sleeve should be provided. If
possible, slots and sleeves should be specified before the building is constructed because
coring (e.g., cutting) holes through existing concrete:
- Is expensive.
- Can create dust or water damage.
- Can compromise structural .integrity.
• Conduits-These are a common method for routing cable through building walls and
floors. Specify bushings at the conduit ends to avoid damage to cable sheaths. Use cable
sheaves if cable bends are required near the conduit. Although conduits may be used both
within and between ERs, they generally are not recommended for cable distribution within
ERs (unless required by code) because conduits:
- Arc expensive.
·- Have limited bulk capacity.
- Accommodate change poorly.
Whenever practical, locate cross-connects near the end of the backbone pathways to
minimize the need for cable routing in the ER.
NOTE: See Chapter 4: Backbone Distribution Systems and Chapter 5: Horizontal
Distribution Systems for additional information on these and other cable pathways.
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Chapter 3: Telecommunications Spaces
Electrical Power
Electrical Power Requirements
Most new telecommunications systems have strict electrical power requirements. To provide
electrical power and ensure smooth installation and good service after cutover, carefully
follow equipment manufacturer's requirements and guidelines. These can be used to
determine the voltage and current requirements for all the equipment to be installed in the
ER. Consideration should be given to providing spare capacity for future expansion.
Information sources include:
• Manufacturer's website
• Equipment O&M manuals
• Manufacturer's data sheets
• Equipment nameplate data
• Applicable code requirements
NOTE: For further information about electrical power requirements, see Appendix A: Codes,
Standards, Regulations, and Organizations, Chapter 8: Bonding and Grounding
(Earthing), and Chapter 9: Power Distribution.
Coordinating with Other Electrical Facilities
Although the ICT distribution designer is usually not responsible for designing or installing
electrical power equipment, the TCT distribution designer shall become familiar with the
equipment and be capable of specifying electrical power service requirements for the
ER, based on present and projected customer needs. The lCT distribution designer shall
coordinate with the qualified professionals responsible for the electrical power systems,
grounding (earthing), power conditioning, and backup power.
It is not uncommon for the ER to have multiple ac power panels capable of supporting
multiple voltages within the space. Based on equipment requirements and future growth,
qualified professionals will be able to determine the panel voltage and amperage requirements
for service.
Maintaining Electrical Power Quality
Telecommunications equipment is sensitive to electrical power fluctuations. Because of this
sensitivity, the ICT distribution designer should consider providing:
• Dedicated branch circuits serving individual outlets.
• Dedicated electrical power feeders.
• Power conditioning.
• Backup power.
• Effective telecommunications bonding and grounding (earthing) infrastructure.
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Maintaining Electrical Power Quality, continued
If additional power conditioning, backup, or standby systems are required for the equipment,
allocate space and allow for HVAC loading in the ER for these systems.
NOTE: For further details on electrical power systems, see Chapter 8: Bonding and
Grounding (Earthing) and Chapter 9: Power Distribution.
Using Dedicated Branch Circuits
A dedicated branch circuit serves a single outlet utilizing a dedicated phase, neutral, and
ground conductor. This outlet shall be a receptacle for cord-and-plug or equipment power
terminal for hard-wired equipment. Every rack, cabinet, or enclosure is fed trom an electrical
subpanel with its own overcurrent protection device (e.g., circuit breaker). In higher load
applications, multiple dedicated branch circuits per rack, cabinet, or enclosure may be
required.
NOTE: Sharing or daisy-chaining any branch circuit conductors or receptacles increases the
likelihood of overloading the branch circuit, causing the overcurrent device (circuit
breaker) to trip.
Using Dedicated Electrical Power Feeders
The feeders that supply the electrical power for telecommunications equipment in ERs should
be dedicated only to supplying that equipment. More than one dedicated feeder may be
required for large installations with a wide variety of telecommunications equipment.
A separate feeder, conduit, and distribution panel should supply the electrical power
required for other equipment in the room (e.g., fluorescent lighting, motors, air conditioning
equipment).
Using dedicated circuits minimizes electrical interference between systems. Separating
feeders reduces the chance that electrical noise and impulses generated by the other loads will
degrade the performance of the telecommunications equipment.
Although their initial installation cost is higher, separate feeders greatly enhance equipment
operation.
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Power Conditioning
The sensitivity of telecommunications equipment to electrical power fluctuations is
a significant issue in assuring system reliability and longevity. For this reason, it is
recommended that an electrical power quality audit be performed to assess the need for
additional power conditioning before telecommunications equipment is installed.
These audits are typically performed by a qualified person and, in some cases, available as a
service provided by the utility company, often free of charge. The ICT distribution designer
should evaluate the audit results with input from audit suppliers, utility engineers, and
equipment manufacturers to determine if power conditioning is required.
Power conditioning can be placed at the building's main power entrance panel or other major
distribution point.
NOTES: In many cases, backup power units are also equipped to function as in-line power
conditioners.
Surge protection devices may be placed in line with the commercial power entrance
feeds or at local or sub-distribution panels where additional protection is desired.
Backup Power
Because ofthe mission critical nature of the ER, it is strongly recommended that backup
power be provided in the event of a power failure. If standby power (e.g., a UPS or generator)
is available in the building, the ICT distribution designer should consider connecting it
to the electrical circuits that feed the ER. Electrical infrastructure for TRs should not be
connected to a backup generator that is dedicated to emergency or legally required loads
unless otherwise required or allowed by applicable codes. A qualified professional should be
consulted prior to connecting loads to an existing generator system.
If batteries are required for backup systems, observe the manufacturer's requirements for
ventilation, explosion, containment, maintenance, and other safety concerns.
NOTE: For further information on the use of batteries in electrical power systems, see
Chapter 9: Power Distribution.
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Chapter 3: Telecommunications Spaces
Heating, Ventilation, and Air-Conditioning (HVAC)
Environmental Control
Overview
Telecommunications equipment can be sensitive to environmental conditions and typically
has strict requirements for its operating environment. Therefore, an ER shall have either
dedicated HVAC equipment or access to the main building HVAC delivery system. If
environmental control is provided by the main building delivery system, the ER should have
separate controls from other rooms in the building.
In addition to temperature control, the environmental requirements for telecommunications
equipment may include:
• Humidity control.
• Dust and contaminant control.
Environmental requirements for equipment vary from manufacturer to manut~ICturer. The
manufacturer's requirements should be followed exactly to ensure reliable operation and to
keep warranties valid.
The TCT distribution designer should consult professional, qualified HVAC engineers when
addressing ER HVAC requirements.
Heating, Ventilation, and Air-Conditioning (HVAC) Operation
Telecommunications equipment usually requires the HVAC system to function properly at all
times (e.g., 24 hours per day, 365 days per year). If a building's HVAC system cannot ensure
continuous operation, a stand-alone HVAC unit with independent controls should be provided
for the ER. ff an emergency power source is available in the building, connect the HVAC
system that serves the ER to the power source.
The HVAC system that serves the ER should be tuned to maintain a positive air pressure
differential with respect to surrounding areas. If environmental conditions warrant, equipment
for the control of humidity and air quality should be provided.
The ICT distribution designer should consider that the following equipment may be located
inside the ER and could affect HVAC sizing requirements:
• Environmental control equipment
• Power distribution/conditioners
• UPS systems
• PDUs
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Chapter 3: Telecommunications Spaces
Environmental Control Requirements
The JCT distribution designer shall consider the heat produced by each piece of equipment
(e.g., BTU) that will be placed in the ER. The final ER design shall accommodate any special
or specific requirements, including future provisions where applicable.
The environmental control systems for the ER should meet applicable standards.
r•iltration systems are required to minimize particle levels in the air. Keep changes in
temperature and humidity to around one percent. HVAC sensors and controls shall be located
in the ER. ideally, the sensors are placed~ 1.52 m (5 ft) AFF.
HVAC systems can have alarm wiring capabilities. At a minimum, the systems should
be alarmed ac for power loss, high and low temperature, high and low humidity, smoke
detection, compressor failures, and water flooding.
HVAC systems should be installed where an external drain is present in order to drain away
moisture, also known as condensate, obtained through the air during the dehumidification
process. A manufactured condensate pan or barrier should be built around the HVAC system
to ensure that condensate does not leak to other areas of the ER instead of flow into the drain.
Within the pan or barrier, a set of contacts is installed, which sets ofT an alarm notifying
personnel that condensate is not properly draining out of the building. Condensate drain lines
shall be free and clear of debris to ensure proper drainage.
HVAC systems shall be routinely maintained. At a minimum of every 6 months, check belts
and filters and provide lubrication to moving parts. Outdoor condensers shall be free of debris
on the cooling fins to ensure proper cooling and compressor cycling.
© 2020 BICSI®
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Chapter 3: Telecommunications Spaces
Miscellaneous Considerations
Maintaining Valid Warranties
To ensure that the warranties on equipment remain in force, the ICT distribution designer
should follow the manufacturer's instructions and requirements exactly. If site constraints
make it impossible to follow the instructions or requirements, consult the manufacturer about
alternatives that will not void the warranty.
If acceptable alternatives can be agreed upon, the manufacturer should be asked to
acknowledge the alternatives in writing.
A good practice is to assemble a binder for the ER that contains equipment, HVAC, structural,
ac power, UPS, and alarm monitoring system warranties and specifications. Safety data sheets
for batteries also shall be maintained in a place where anyone can find and review them.
Design Approval, Buildout, and Final Inspection
Reviewing the Design with the Customer
The ICT distribution designer should review the ER design with the architect, engineers,
building owner, property manager, and customer before proceeding with the buildout and
equipment installation. Include all requirements for customer acceptance in the contract.
Planning the Installation
After the design is completed and approved, the ICT distribution designer should assess
the time required for provisioning the ER and installing each piece of telecommunications
equipment and cabling. From this assessment, the ICT distribution designer can set up the
buildout and equipment installation plan and schedule.
This schedule shall be coordinated with all other work (in progress or planned), including
any:
• Remodeling.
• Office space changes.
• Computer facilities installation.
• AP plans and work schedules.
• Other disciplines (e.g., architectural, electrical, HVAC).
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Chapter 3: Telecommunications Spaces
Installation Access
Because equipment and materials are delivered and installed throughout the construction
cycle, make provisions to ensure a direct, unobstructed passageway between the ER and
deli very vehicles for the duration of the construction project. Make the same provision during
any equipment changeovers.
Installing the Equipment
The buildout and equipment installation plan should be followed closely. The ICT distribution
designer, installers, customer, and other personnel should resolve a deviation from the plan
immediately as required.
Life safety considerations and following the equipment manufacturers' instructions should be
a priority during the buildout and installation of equipment.
Equipment should not be installed until the room is clean, meaning that all other trades have
completed their construction work for the room (e.g., plywood is up; pathways are installed;
flooring and painting are complete; room is totally dust free).
Inspecting the Equipment Room (ER)
When the equipment installation is completed, all work should be inspected. The lCT
distribution designer should:
• Check workmanship for safety, standards, and codes compliance.
• Check for cleanup.
• Check for compliance with construction documents using a checklist to verify that every
contract item is satisfactorily completed.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 3: Telecommunications Spaces
Entrance Facilities
Overview
An EF is an entrance to a building for both public and private network service media,
including wireless. This includes the EP at the building wall or floor, the conduit or pathway,
and continuing on to the entrance room or space.
The EF can be located within a separate room or within the ER. If the EF is within the ER,
additional space shall be designed within the ER.
Telecommunications EFs shall be located in an area or areas of a building that are best suited
to serve the occupants of a building.
This service entrance includes the:
• Path that these facilities follow on private or public property.
• Single or multiple EPs to the building.
• Termination point or DP.
The type and location of the entrance depend upon the:
• Type of facility being used.
• Path the facility follows.
• Building architecture.
• Aesthetics.
Required Service Entrances
Single or multiple service entrances may be required for connections to:
• APs.
• Campus distribution (e.g., LAN, PBX).
• A central station system for ESS systems.
• CATV network.
• Video surveillance systems.
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Chapter 3: Telecommunications Spaces
Entrance Media Types
The types of media entering the EF can include:
• Balanced twisted-pair copper.
• Coaxial.
• Optical fiber.
• Wireless.
Service Entrance Considerations
The service entrance accepts underground, direct-buried, and aerial OSP facilities into the
room.
For more information, sec:
• Chapter 4: Backbone Distribution Systems.
• Chapter 12: Outside Plant.
• The current edition ofBICSJ's Outside Plant Design Reference Manual.
Service entrances also have specific bonding and grounding (earthing) requirements. For
more information, see Chapter 8: Bonding and Grounding (Earthing).
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4
Backbone Distribution
Systems
Chapter 4 describes cabling topologies (including
fundamental and hybrid topologies) and building
backbone and campus backbone distribution systems
design and cabling.
Chapter 4: Backbone Distribution Systems
Table of Contents
Backbone Distribution Systems • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Components of a Backbone Distribution System . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Components of a Backbone Distribution System . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Cabling Topologies .
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Star Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Hierarchical Star Topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Two-Level Hierarchical Star Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Ring Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Physical Ring Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Physical Wired Star/Logical Ring Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Clustered Star Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12
Bus Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Tree and Branch Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Mesh Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Passive Optical Networks (PONs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Point-to-Multipoint Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Point-to-Point (PTP) Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Optical Fiber Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Balanced Twisted-Pair Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Point-to-Point (PTP) Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Balanced Twisted-Pair Cabling Specifications . . . . . . . . . . . . . . . . . . . . . . . . 4-23
Hierarchical Star Campus Backbone Designs ...............••... 4-24
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
First Level Hierarchical Star Campus Backbone Designs . . . . . . . . . . . . . . . . . . . 4-24
Multiple Hierarchical Level Campus Backbone Designs . . . . . . . . . . . . . . . . . . . . 4-25
Backbone Cross-Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27
Support of Other Topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28
Telecommunications Rooms (TRs) and Telecommunications
Enclosures (TEs). ~ ~ ~ ~ ...
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31
Additional Backbone Connections Between Telecommunications Rooms (TRs) ... 4-31
Campus Backbone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31
© 2020 BICSI®
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Chapter 4: Backbone Distribution Systems
Building Backbones . ..........
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-32
Connecting Horizontal Cross-Connects (HCs [Floor Distributors (FDs)]) . . . . . . . . 4-35
Combined Optical Fiber and Balanced Twisted-Pair Backbone . . . . . . . . . . . . . . . 4-36
Equipment Rooms (ERs) and Access Provider (AP) Cabling System Interface
Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37
Choosing_ Media . .
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38
Multimode Optical Fiber Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38
Singlemode Optical Fiber Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38
100-0hm Balanced Twisted-Pair Copper Cable . . . . . . . . . . . . . . . . . . . . . . . . . 4-38
Performance Categories for Multipair Backbone Balanced Twisted-Pair Cable .... 4-39
Advantages of Optical Fiber Backbones for Campus Applications . . . . . . . . . . . . . 4-39
Choosing Optical Fiber Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-40
Backbone Building Pathways (Internal) .......••.•..•••..•••.•. 4-41
Vertically Aligned Telecommunications Rooms (TRs) . . . . . . . . . . . . . . . . . . . . . 4-41
Conduits, Trays, Slots, Sleeves, and Ducts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41
Conduit Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41
Sleeves or Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-43
Sleeve Quantity and Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44
Slot Quantity and Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46
Open Cable Shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46
Elevator Shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46
Enclosed Metallic Raceways or Conduits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46
Cable Trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46
Miscellaneous Support Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-47
Necessary Consultations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-47
Supporting Strand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-47
Other Methods for Securing Vertical Backbone Cable . . . . . . . . . . . . . . . . . . . . . 4-48
Bonding and Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . • • . . . . . . 4-49
Backbone Planning .......
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Optical Fiber Strand Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-49
Criteria for Determining an Optical Fiber Strand Count . . . . . . . . . . . . . . . . . 4-50
Sizing Optical Fiber Backbones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-50
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Chapter 4: Backbone Distribution Systems
Indoor Hardware
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Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
Mounting Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
Rack-Mounted Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
Wall-Mounted Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
Fiber Splicing Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51
Terminating Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-52
Patch Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-52
Ethernet in the First Mile (EFM) . . . . • • . . . . . . . . . . . . . . . . . • • • • . . . 4-53
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
Ethernet in the First Mile (EFM) Physical Layer Specifications . . . . . . . . . . . . . . . 4-54
© 2020 BICSI®
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Chapter 4: Backbone Distribution Systems
Figures
Figure 4.1
Star topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Figure 4.2
Hierarchical star topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Figure 4.3
Ring topology (simplified) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Figure 4.4
Buildings connected by a physical ring topology . . . . . . . . . . . . . . . . . . 4-9
Figure 4.5
Main backbone ring and redundant backbone star combined . . . . . . . . 4-10
Figure 4.6
Physical star/logical ring topology . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Figure 4. 7
Clustered star topology with physical star/logical ring . . . . . . . . . . . . . 4-12
Figure 4.8
Bus topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13
Figure 4.9
Tree and branch topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Figure 4.10
Fully connected mesh topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Figure 4.11
Partially connected mesh topology . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Figure 4.12
Point-to-multipoint optical topology . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Figure 4.13
PTP optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19
Figure 4.14
PTP balanced twisted-pair topology . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Figure 4.15
Typical backbone hierarchical star topology for multiple buildings on
a campus (inside and outside distribution) . . . . . . . . . . . . . . . . . . . . . 4-24
Figure 4.16
Example of multiple hierarchical level campus backbone design ...... 4-26
Figure 4.17
Levels of cross-connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27
Figure 4.18
Logical bus topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28
Figure 4.19
Logical ring topology implemented using a physical star topology ..... 4-29
Figure 4.20
Logical tree topology implemented using a hierarchical star topology .. 4-29
Figure 4.21
Star building backbone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33
Figure 4.22
Hierarchical star building backbone . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34
Figure 4.23
Redundant routing for building backbone (HCs [FDs] not linked) ..... 4-35
Figure 4.24
Example of combined optical fiber/balanced twisted-pair backbone
supporting voice and data traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36
Figure 4.25
ERs and AP cabling system interface cabling . . . . . . . . . . . . . . . . . . . 4-37
Figure 4.26
Typical office building pathway layout . . . . . . . . . . . . . . . . . . . . . . . . 4-44
Figure 4.27
Typical sleeve and slot installations . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45
Figure 4.28
EFM network boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Tables
Table 4.1
Backbone distribution system components . . . . . . . . . . . . . . . . . . . . . . 4-1
Table 4.2
EFM installed singlemode optical fiber . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Table 4.3
Common conduit sizes with vernacular . . . . . . . . . . . . . . . . . . . . . . . 4-41
Table 4.4
Summary of EFM physical layer signaling systems . . . . . . . . . . . . . . . 4-54
© 2020 BICSJ:®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Backbone Distribution Systems
Introduction
A backbone distribution system is the part of a premises distribution system that provides
connection between telecommunications spaces.
A backbone distribution system typically provides:
• Building connections between floors in multi-story buildings.
• Campus connections in multi-building environments.
Components of a Backbone Distribution System
A backbone distribution system may consist of any or all of the following:
• Cable pathways (i.e., inside and outside plant)
• ERs that may contain l1Cs (FDs), ICs (BDs), or MCs (CDs)
• TRs that typically contain HCs (FDs)
• TEs that typically contain HCs (FDs)
• An EF
• Transmission media (i.e., cables and connecting hardware)
• Miscellaneous support facilities
These seven components are described in Table 4.1.
Table 4.1
Backbone distribution system components
Component
Description
Cable pathways
Shafts, conduits, raceways, tray, floor penetrations (e.g., sleeves or
slots), maintenance holes, hand holes, conduit banks (and other
outside plant pathways) that provide routing space for cables.
Equipment room
An environmentally controlled centralized space for
telecommunications equipment that usually houses a main or
intermediate cross-connect. CriA)
Telecommunications room
An enclosed architectural space for housing telecommunications
equipment, cable terminations, and cross-connect cabling. (TJA)
Telecommunications enclosure
A case or housing that may contain telecommunications equipment,
cable terminations, or horizontal cross-connect cabling. (TIA)
Entrance facility
An entrance to a building for both public and private network service
cables (including wireless), including the entrance point of the
building and continuing to the entrance room or space. (TTA)
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Components of a Backbone Distribution System
Table 4.1, continued
Backbone distribution system components
Component
Description
Transmission media
The actual medium, which may be:
• Optical fiber.
• Balanced twisted-pair.
• Coaxial.
• Wireless.
Connecting hardware, which may be:
• Connecting blocks.
• Patch panels.
• Patch cords and jumpers.
• Interconnections.
• Cross-connections.
NOTE: Backbone cabling also can be a combination of media,
wireless, and free space optics equipment.
Miscellaneous support
Materials needed for the proper termination and facilities installation
of the backbone cables.
These include:
• Cable support hardware.
• Firestop (see Chapter 7: Firestop Systems).
• Bonding hardware (see Chapter 8: Bonding and Grounding
[Earthing]).
• Protection and security.
HC (FD)
A group of connectors (e.g., patch panel, punch-down block) that
allow equipment and backbone cabling to be cross-connected or
interconnected with patch cords or jumpers to horizontal cabling.
Floor distributor is the international equivalent term for horizontal
cross-connect.
IC (BD)
The connection point between a backbone cable that extends trom
the MC (CD [first level backbone]) and the backbone cable from the
HC (FD [second level backbone]). Building distributor is the
international equivalent term for intermediate cross-connect.
MC (CD)
The cross-connect normally located in the (main) equipment room for
cross-connection and interconnection of entrance cables, first level
backbone cables, and equipment cables. Campus distributor is the
international equivalent term for main cross-connect.
HC (FD) = Horizontal cross-connect (floor distributor)
IC (BD) =Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
TIA =Telecommunications Industry Association
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Chapter 4: Backbone Distribution Systems
Cabling Topologies
Overview
There are three fundamental cabling topologies-star, ring, and bus. From these three, a
number of hybrid topologies have developed, including:
• Hierarchical star.
• Star-wired ring.
• Clustered star.
• Tree and branch.
• Mesh.
Campus backbone cabling is the segment of network topologies that presents the TCT
designer and end user with the most options and challenges, particularly in major networks
such as universities, large industrial parks, military bases, wide area K-12 school networks,
govemment or municipal networks, and major corporate and research campuses.
Campus and wide area backbone cabling and infrastructure is also the network segment most
affected by physical considerations (e.g., infrastructure availability, private easements, public
R/W, physical barriers, security, and environmental restrictions).
As protection against network downtime, many cabling system designers build redundancy
into their design approach. Options for redundancy include active equipment network
devices that are coupled to conductors in the same cable as the primary network system. If
the primary network system fails, the redundant network system will activate immediately.
This protects against active device failure; however, it does not help in the rare instance
of a complete cable cut or some other form of disconnection, resulting in an interruption
of network transmission (see the note below regarding physical diverse routing for more
information). Additional examples of disconnection may include:
• Removal of patch cord assemblies or equipment cords on the user side of the system.
• Disconnection of connectors from their associated adapters on the cabling side of the
system.
• One or more conductors that break or exhibit excessive Joss on either the user side or
cabling side of the system.
NOTES: The user side of the cabling system is accessible to the user, and equipment cords or
cables are used to plug into the user side of the cabling system. The cabling side of
the system is accessible to cabling installers. Connections made on the cabling side
of a system are part of the permanent link model.
Physical diverse routing provides the most protection. A redundant cable is placed
in a second diverse route with redundant network switching equipment that will
activate immediately if cable is damaged.
Physical diversity is used in cases where minimum downtime for the infrastructure
is a requirement. Physically diverse cabling is more costly than coupled active
equipment devices. In many cases (e.g., data centers) both cable diverse routing and
network equipment redundancy is a requirement.
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Star Topology
A star topology generally is deployed for OSP cabling. Star configurations allow all buildings
to be cabled directly from the MC (CD). These configurations centralize the physical
management of the backbone network.
A star topology directly links all buildings requiring connection to the MC (CD), as shown in
Figure 4.1. 'T'hese direct links between the MC (CD) and IC (BD) are sometimes referred to
as home runs. The cross-connect in each building then becomes the IC (BD), linking the TRs
from their associated HC (FD) in each building to the MC (CD).
By centralizing the physical management of the backbone cabling at the MC (CD), the owner
has the opportunity to configure, manage, and provision the network to a remote location or
campus from the centralized point. For example, this connection can be made via microwave,
satellite, or leased lines.
The MC (CD) should be colocated with or close to the primary ER. Ideally, the MC (CD)
will:
• Be at the center of the buildings being served.
• Provide adequate space for cross-connect hardware and equipment.
• Have suitable pathways linking it to the other buildings.
Some of the advantages of using a star topology for the campus backbone cabling are that it:
• Provides centralized facilities administration.
• Allows testing and reconfiguration of the system's topology and applications from the
MC (CD).
• Allows easy maintenance and security against unauthorized access.
• Provides increased flexibility.
• Allows the easy addition of future campus backbones.
Some of the disadvantages of using a star topology campus backbone cabling are that it:
• Introduces single points of failure.
• Increases cost.
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Chapter 4: Backbone Distribution Systems
Star Topology, continued
Figure 4.1
Star topology
Building
MC (CD)= Main cross-connect (campus distributor)
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Chapter 4: Backbone Distribution Systems
Hierarchical Star Topologies
Hierarchical refers to a tree-like structure where a trunk and branch relationship exists. Each
trunk can have many branches. F'igure 4.2 is an example of a star topology that is hierarchical
in nature.
Figure 4.2
Hierarchical star topology
G
MC (CD)= Main cross-connect (campus distributor)
Other arrangements might include:
• High-rise buildings in which the backbone may be entirely inside the building.
• Campus systems containing small buildings with only one HC (FD) per building, thereby
eliminating the need for an IC (BD).
In typical applications, the link from the:
• MC (CD) to IC (BD) may be an interbuilding or intrabuilding link.
• lC (BD) to HC (FD) will typically be an intrabuilding link.
NOTE: Bridged taps are not permitted as part of the building backbone cabling.
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Chapter 4: Backbone Distribution Systems
Hierarchical Star Topologies, continued
If the distance from the switch to the last workstation exceeds the transmission limit, the
ICT designer should consider using a hierarchical star configuration. In this configuration, the
first-level backbone either cross-connects or interconnects to the second-level backbone via
active network equipment.
Each cabling segment may connect to a centralized location that supports the area as a star
topology where Building A is star cabled to Building F, and then Building F is star cabled to
Buildings G, H, I, and J (see Figure 4.3). Node locations can be connected to other topologies
to support technologies and equipment used for wide area applications such as:
• Wireless.
•SONET.
• Integrated services digital network.
• Digital subscriber line.
• ATM.
• Hybrid fiber/coaxial.
• Gigabit Ethernet.
Two-level Hierarchical Star Topology
A two-level hierarchical star design provides an interbuilding backbone that uses selected ICs
(BDs) to serve a number of buildings rather than linking all the buildings directly to the MC
(CD). The ICs (BDs) are then linked to the MC (CD).
Consider using a two-level hierarchical star when available pathways do not allow for all
cables to be routed to an MC (CD) or when geographical or user grouping requirements make
it desirable to physically segment the network. In large networks, this allows electronics
(e.g., switches) to be used more effectively to utilize bandwidth and distance capabilities of
the cabling or to segment the network physically.
Many OSP designers consider the two-level hierarchical star beneficial especially if the
number ofinterbuilding TCs (BDs) is held to a minimum.
When the two-level hierarchical star is used for an interbuilding backbone, a physical star
should be implemented in all segments. This will ensure that flexibility, versatility, and
manageability are maintained. Multiple levels of hierarchical star also may be considered.
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Chapter 4: Backbone Distribution Systems
Ring Topology
The optical fiber ring topology depicted in Figure 4.3 is a simplified view of a typical ring
application. Optical fiber ring topology strategies can become sophisticated and complex
in their routing schemes and primary and protection switching capabilities. Most simple
rings are designed to provide a primary path and a secondary path in case there is either an
electronic failure at a node site or a service interruption related to the cable.
In ring topology, separate and independent physical pathways should be considered for
primary and secondary rings.
Figure 4.3
Ring topology (simplified)
~~
Ring signaling
direction
Node C
Optical fiber ring topologies are increasingly becoming the normal design architecture
for OSP operations because they can support high-bandwidth transport applications. Ring
topologies provide:
• Fault-tolerant redundant routing.
• Greater reliability and significantly less cabling service downtime.
• Flexible architecture.
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Chapter 4: Backbone Distribution Systems
Physical Ring Topology
The designer may consider using a physical ring (see Figure 4.4) to link the interbuilding lCs
(BDs) and MC (CD) when:
• The existing pathways (e.g., conduit) support it.
• The primary purpose ofthe network is optical fiber distributed data interface, SO NET, token
ring, or reverse path Ethernet.
• There is a redundant cable path.
Figure 4.4
Buildings connected by a physical ring topology
(See note)
IC (BD)
IC (BD)
IC (BD)
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
NOTE: This generally is not recommended without direct connection to an MC (CD).
The typical optical fiber cores/strands design for a cabling system that provides physical ring
routing would dedicate some of the optical fiber core strands to a ring and some to a star by
splicing through the !Cs (BDs) back to the MC (CD).
Figure 4.5 illustrates a robust optical fiber cabling system configuration that utilizes both
a star and ring topology. However, the OSP designer must have a significantly detailed
definition of present and future telecommunications requirements before designing this kind
of arrangement. Other cable types may follow this same topology.
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Chapter 4: Backbone Distribution Systems
Physical Ring Topology, continued
Figure 4.5
Main backbone ring and redundant backbone star combined
MC (CD)
IC (BD) 1
IC (BD) 3
c
'l
I
-::
~
I
:I
:I
I
I
I'
I
:I
:I
I
I'
I
IC (BD) 2
,-------,
48-0ptical fiber cable
(6 ring optical fibers and
42 star optical fibers)
:I
:I
I
I'
I
:I
:I
I
I'
I
I,
I
1:
1:
~I
I
I!
I
:I
_:
P,1 ',
1:
I:
I
'I
I
I
'I
1:
I
I:
~\~~-"'--~~-~~~-~~~--~.,.{
_y')j'
6 Ring fibers
6 Star fibers
12 Star fibers
Optical fiber patch panel
Optical fiber splice center
•
IC (BD)
MC (CD)
TDMM, 14th edition
Splices
Intermediate cross-connect (building distributor)
Main cross-connect (campus distributor)
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Chapter 4: Backbone Distribution Systems
Physical Wired Star/logical Ring Topology
A physical star/logical ring topology indicates that the OSP cable is physically constructed in
a star configuration, but the signaling will be routed in a logical ring topology. This type of
configuration should be used when the OSP designer determines that a physical ring route is
not possible or an existing cable will be used in a segment of the total project (see Figure 4.6).
Figure 4.6
Physical star/logical ring topology
Node C
Node B
IC (BD)
Node A
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
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Chapter 4: Backbone Distribution Systems
Clustered Star Topology
A clustered star with or without a physical star/logical ring indicates that from the MC (CD)
to the node sites, the topology can be either a star or a ring topology (see Figure 4.7). This
determination is at the designer's discretion and is based upon the electronics, designer's
survivability plans, and transmission budget selected at the MC (CD) and each node site.
Figure 4.7
Clustered star topology with physical star/logical ring
Building 4
Building 3
Building 5
Building 2
Building 6
0
Building 7
~0 Building 8
...
MC (CD)
Node site C
Building 1
MC (CD)== Main cross-connect (campus distributor)
At the node site, the buildings are served via a physical star topology. The node sites have
the ability to be either a star or ring configuration. This topology allows a designer to provide
for fault-tolerant redundant routing at the node locations. At the same time, the designer can
reduce the design costs for the electronics and cable from the node sites to the buildings via
a ring or star network topology. This configuration also takes advantage of the concentration
of electronic equipment in a common location for network management operations and
efficiency.
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Chapter 4: Backbone Distribution Systems
Bus Topology
A bus topology is a linear configuration of cabling that has limited application if the designer
is looking for fault-tolerant redundancy (see Figure 4.8). A bus topology is adequate if the
route is secure (protected from breaks), redundancy is not required, and the system traffic
is not of a significantly critical nature to require alternate routing. All points along the cable
route are in communication with each other. If the route should suffer a break, all network
communications would be lost.
Figure 4.8
Bus topology
Building B
L I C (BD)
IC (BD)
Building C
Building A
ER
Building D
ER"" Equipment room
IC (BD) == Intermediate cross-connect (building distributor)
MC (CD)== Main cross-connect (campus distributor)
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Chapter 4: Backbone Distribution Systems
Tree and Branch Topology
Tree and branch topology typically refers to the configuration of the cabling from a node site
or directly from the MC (CD). This terminology is used in the planning for coaxial cables
for cable TV (CATV) operations. The terminology describes the main trunk of a tree with
subsequent branches extending from this trunk line. It may extend in multiple directions.
The trunk is normally referred to in the telephony industry as feeder cable, and the branch is
distribution cable (see Figure 4.9). In the CATV industry, the terminology is reversed, and the
trunk is the main line from the headend to the branch, which is called the feeder cable. The
parameters for the design of this type of network are dependent upon the loss characteristics
of the coaxial cabling and the geographic area to be served.
Figure 4.9
Tree and branch topology
/ S e e note
I
'
'
MC (CD)= Main cross-connect (campus distributor)
NOTE: Locations such as this in a cabling system can take on many different configurations,
depending on the type of cabling system. For cabling in general, this point could be
an HH, pedestal, or splice pit with one cable fi:om the MC (CD) through the point to
Building A and one cable from the MC (CD) through the point to Building B. If this
is a balanced twisted-pair cable, this could be a I00-pair cable from the MC (CD) to
an MH with a splice. The splice could have the first binder group run to Building B,
the second binder group run to Building A, and the third and fourth binder groups
as spares for future requirements. If this were a CATV cable, this could be a feeder
or trunk cable to an HH and a tap, sending one cable to Building A and one cable to
Building B. This also could be an optical fiber network with a cable from the MC
(CD) to an MH and spliced into an optical fiber cable to Buildings A and B.
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Chapter 4: Backbone Distribution Systems
Mesh Topology
Mesh topology typically refers to the configuration of cabling multiple links between node
sites. There are two types of mesh topologies: fully connected and partially connected.
In a fully connected mesh topology, the nodes of the network are connected to each of the
other nodes in the network with a PTP link (see Figure 4.1 0). This makes it possible for
data to be simultaneously transmitted from a single node to all of the other nodes. T'he fully
connected mesh topology is generally too costly and complex for most networks, although
this topology is used when there are a limited number of nodes and redundancy is important.
This topology allows for a high level of routing redundancy and is commonly used in
provider and enterprise networks to connect their routers.
Figure 4.10
Fully connected mesh topology
Node C
Node F
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Chapter 4: Backbone Distribution Systems
Mesh Topology, continued
To calculate the number of links required for a fully connected mesh topology, the following
formula can be used:
N =number of links
X
=
number of nodes
N =X* (X-l)
2
Where X= 6
N
=
6
* (6-l)
2
N=6
*5
2
N=30
2
N= 15
A partially connected mesh topology is where some of the nodes of the network are
connected to more than one node in the network with a PTP link (see Figure 4.11 ). This
makes it possible to take advantage of some of the redundancy that is provided in a fully
connected mesh topology without the expense and complexity required for a connection
between every node in the network.
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Chapter 4: Backbone Distribution Systems
Mesh Topology, continued
Figure 4.11
Partially connected mesh topology
Node F
Node D
In networks that are based on a fully or partially connected mesh topology, all of the data
that is transmitted between nodes in the network take the shortest path (or least costly path)
between nodes except in the case of a failure or break in one of the links, in which case the
data takes an alternative path to the destination. This requires that the nodes of the network
possess some type of logical routing protocol to determine the correct path to use.
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Chapter 4: Backbone Distribution Systems
Passive Optical Networks (PONs)
Within backbone applications, a PON is typically a point-to-multipoint, fiber to the premises
network architecture, in which unpowered optical splitters are used to enable a single fiber to
serve multiple premises, typically 32-128. A PON configuration reduces the amount of optical
fiber and CO equipment required, compared with PTP architectures. Depending on where the
PON terminates, the system can be described as fiber to the curb, fiber to the building, or fiber
to the home.
NOTE: For detailed information on PONs used within horizontal cabling network
applications, please refer to Chapter 5: Horizontal Distribution Systems.
Point-to-Multipoint Topology
The EFM objective to support EPONs is based on a number of economic advantages. The
aggregation device, called the OLT, supports a minimum of 16 subscribers per port by means
of a passive optical splitter. Thus, the EPON minimizes the number of fibers that need to be
managed in the SP's point of presence or CO, minimizes the number of CO transceivers, and
reduces the rack space required in the CO compared with a PTP topology. This economic
benefit is significant.
The EPON topology is illustrated in Figure 4.12. The optical distribution network consists
of the optical fiber distribution plant and the passive optical splitter. The EPON has no active
Ethernet or optical equipment in the distribution or access layer in the neighborhood. The
ONU provides the necessary functionality to connect the SP-owned optical fiber to the media
in the residence. The ONU is assumed to be on the outside of the residence.
Figure 4.12
Point-to-multipoint optical topology
Feeder
Distribution
CO or
point of
presence
Optical
splitter
r-1_:_1~6_
_J
Point-to-multipoint
single optical fiber
Switch
CO = Central office
OLT = Optical line terminal
ONU = Optical network unit
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Passive Optical Networks (PONs), continued
Point-to-Point (PTP) Topology
'rhe 1OOOBASE-X deployment on a single strand of singlemode optical fiber reduces the cost
of optical fiber deployment in the link between the business or house and the distribution
or access switch. The 1OOOBASE-X extended temperature range optical fiber enables SPs
to locate the ONT outside the residence at the demarcation point between the optical fiber
network and the business or home network (i.e., operational temperature ranges from- 4.4 °C
[- 40 °F] to 85 °C [185 °F]).
Gigabit Ethernet over PTP optical fiber provides enough bandwidth to ensure a very long
lifespan for the network infrastructure; namely, the optical fiber infrastructure may be
amortized over periods of time ranging from 20 or more years.
Figure 4.13 shows the topology of a P'T'P network over optical fiber. Multiple devices in the
home can be connected to a single Ethernet port from the home to the carrier. The ONT is
responsible for media conversion from the optical fiber to the balanced twisted-pair network
or other media in the home.
Figure 4.13
PTP optical fiber
Distribution
CO or
point of
presence
Feeder
Switch
Single I
optical I
fiber
1
-=======. . .,.1---CO =
ONT =
PTP =
TP =
© 2020 BICSI®
1
Distribution
frame
I
I
Access network
-----1..-
Central office
Optical network terminal
Point-to-point
Transition point
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Chapter 4: Backbone Distribution Systems
Passive Optical Networks (PONs), continued
Optical Fiber Specifications
·rable 4.2 provides a reference to the International 'I'elecommunication UnionTelecommunication Standardization Sector (ITU-T) Series G recommendations that
collectively represent 99 percent of the installed base of singlemode optical fibers for PON
networks. The JTU-T recommendations have been used extensively in subscriber access
networks primarily in support of the SOH and SONET digital transmission hierarchies.
JTU-T G series specifications may also be found in IEC 60793-2-50.
Table 4.2
EFM installed singlemode optical Aber
lTU-T
Recommendation
Zero-Dispersion
Wavelength Range
G.652
Notes
Dispersion unshifted fiber
G.652.B
1300 to 1324 nm
Supports 1 Gigabit Ethernet, I 0 Gigabit Ethernet and
SONET.
Supports some higher bit rate applications,
(e.g., STM-64, STM-256) depending on the system
architecture.
0.652.0
1300 to 1324 nm
Supports G.652.B and allows transmissions in
portions of the 1260 nm to 1625 nm wavelength range.
Dispersion shifted fiber
0.653
G.653.A
1525 to 1575 nm
Supports STM-64 and SOH systems with an unequal
channel spacing in the 1550 nm wavelength region.
G.653.B
1460 nm to 1625 nm and
within a pair of bounding
curves defined by wavelength
Supports 0.653.A applications, some STM-256
applications, and allows STM-64 systems to lengths
longer than 400 km.
G.655
Non-zero dispersion shifted tiber. Primarily utilized in
submarine and long-haul terrestrial applications.
G.655.C
1530 to 1565 nm
C and L-band compatible
G.655.D
1460 mn to 1625 nm and
within a pair of bounding
curves defined by wavelength
Supports 0.655.C applications at wavelengths greater
than 1530 nm. Can suppoti CWDM at channels greater
than 1471nm.
G.655.E
1460 nm to 1625 nm and
within a pair of bounding
curves defined by wavelength
Supports small channel spacings and G.655.C
applications.
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Chapter 4: Backbone Distribution Systems
Passive Optical Networks (PONs), continued
Table 4.2, continued
Ethernet in the first mile installed singlemode optical fiber
ITU-T
Recommendation
Zero-Dispersion
Wavelength Range
G.656
1460 nm to 1625 nm and
within a pair of bounding
curves defined by wavelength
G.657
Notes
Wideband non-zero dispersion shifted fiber, used in
both CWDM and DWDM systems.
Bending loss insensitive fiber. Supports small volume
fiber management systems and low radius mounting.
G.657.A
1300 to 1324 nm
0-, E-, S-, C and L-band compatible
G.657.B
1250 to 1350 nm
Compatible with lTU-T G.657.A (and TTU-T G.652.D)
tlbers and systems within access networks. Suitable for
transmission at 1310, 1550, and 1625 nm for restricted
distances.
CWDM =Coarse wavelength division multiplexing
DWDM = Dense wavelength division multiplexing
ITU-T =International Telecommunication Union-Telecommunication Standardization Sector
SDH =Synchronous digital hierarchy
STM =Synchronous transport module
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Chapter 4: Backbone Distribution Systems
Balanced Twisted-Pair Cabling
Point-to-Point (PTP) Topology
The achievable data rates and distances specified in the physical layer are based on the types
of transmitters and receivers used, the functions that translate the data into signals (encoding),
and the transmission media. Termed EoDSL, rate names include 1OPASS-T ( 10 Mb/s) for
short reach up to ;:::;750 111 (2461 ft) and 2PASS-TL (2 Mb/s) for long reach up to ;:::;2700 111
(8858 ft).
Ethernet over PTP balanced twisted-pair cable is probably the best fit for established
neighborhoods, business parks, and MD Us because it can reuse the existing first mile of
voice grade, balanced twisted-pair cable (see Figure 4.14). MDUs are a class of buildings
that include apartments, office buildings, multi-tenant units, and hotels or multiple hospitality
units.
Figure 4.14
PTP balanced twisted-pair topology
CO or
point of
presence
Feeder
Distribution
Customer
premises
1
1
Distribution
frame
1
Unbundled
network
element
Switch
CO = Central office
NID = Network interface device
RT = Remote terminal
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Balanced Twisted-Pair Cabling, continued
Balanced Twisted-Pair Cabling Specifications
While EFM cabling characteristics are not as well defined as those of LAN cabling, IEEE
802.3-2012, IEEE Standardfbr Ethernet, has incorporated most ofthe current telephony
infrastructure of balanced twisted-pair cabling for EFM. EFM cabling specifications can also
be supplemented by standards such as ISO/IEC 11801-1, Jnfbrmation Technology- Generic
Cablingfi;r Customer Premises--Part 1: General Requirements, and the ANSI/TIA-568
series cabling standards.
Additionally, to help the TCT industry to plan quality voice band transmission performance
on unbundled voice grade analog loops, Committee T I A I. 7, Summary of Objective Audio
Quality Measure Performance Data, the T 1 Working Group on Signal Processing and
Network Perfonnance for Voiceband Services, developed Technical Report No. 60 (TR 60).
This technical report describes transmission performance parameters of unbundled loops used
to provide connectivity to subscribers' premises for analog voice band services.
The technologies used in unbundled voice grade analog loops are characterized in the report.
They consist of passive balanced twisted-pair networks (metallic facilities) both loaded and
unloaded. Load coils are sometimes used to improve the transmission performance. Loading
refers to the addition of load coils in the transmission to reduce the insertion loss in the
voice band range (approximately 300 to 3400Hz). However, it does this at the expense of
increasing the insertion loss of the transmission path outside the normal passband range.
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Chapter 4: Backbone Distribution Systems
Hierarchical Star Campus Backbone Designs
Overview
This topology applies to the physical transmission media (e.g., optical fiber, balanced twistedpair, sometimes coaxial cabling).
The services distributed by the backbone may share the same physical cabling over all or a
portion of the distances involved, depending upon the:
• Characteristics of the site.
• Distribution of the telecommunications equipment.
First level Hierarchical Star Campus Backbone Designs
A design for a first level hierarchical star campus backbone would link all the buildings to
the MC (CD). The cross-connect in each building would then become the IC (BD), linking
the HCs (FDs) in each building to the MC (CD). This arrangement is called a first level
hierarchical star campus backbone because only one level exists between the MC (CD) and
the IC (BD) of each building. An example is illustrated in Figure 4.15.
Figure 4.15
Typical backbone hierarchical star topology for multiple buildings on a campus (inside and outside
distribution)
Telecommunications--......._
service entrance
'-.....
Intrabuilding
backbone
MC (CD)
IC (BD)
Interbuilding '""""\.
backbone
'\
IC (BD)
HC (FD)
Building 3
Building 2
HC (FD) = Horizontal cross-connect (floor distributor)
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
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first level Hierarchical Star Campus Backbone Designs, continued
The MC (CD) should be close to (if not located in) the main ER (e.g., data center or computer
room).
Ideally, the MC (CD) would:
• Be at the center of the buildings being served.
• Have adequate space for the cross-connect hardware and equipment.
• Have suitable pathways linking it to the other buildings.
NOTE: See the latest edition ofBICSl's OSPDRMfor OSP pathway information.
Some of the advantages of using a first level hierarchical star for the campus backbone are
that it:
• Provides a single point of control for system administration.
• Allows testing and recontiguration of the system's topology and applications from the
MC (CD).
• Allows easy maintenance and security against unauthorized access.
• Provides increased flexibility.
• Allows the easy addition of future campus backbones.
Multiple Hierarchical level Campus Backbone Designs
Larger campus cabling systems may require multiple hierarchical levels. This design provides
a campus backbone that uses selected lCs (BDs) to serve a number ofbuildings (e.g., the
science buildings in Figure 4.16) rather than linking all the buildings directly to the MC (CD).
The TCs (BDs) are then linked to the MC (CD).
This design could be used in the following cases:
• Available pathways do not allow for all cables to be routed to an MC (CD).
• Geographical or user grouping requirements make it desirable to segment the cabling
system.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Multiple Hierarchical level Campus Backbone Designs, continued
An example of this arrangement is illustrated in Figure 4.16.
Figure 4.16
Example of multiple hierarchical level campus backbone design
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
This design often allows segmentation of the cabling system. When this kind of hierarchical
star is used for a campus backbone, it may be implemented by a physical star in all segments.
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Backbone Cross-Connect
A backbone distribution system shall have no more than two levels of cross-connections.
Connections between any two HCs (FDs) shall not pass through more than three crossconnections (see Figure 4.17).
Figure 4.17
Levels of cross-connections
Building 1
Building 2
~---
I
I
MC
(CD)
I
- - - - - - - ·--
·------,
IBrown~
X
rl
I
I
: First level_/
interbuilding
backbone
1 - - ~ -First level
I
I
I
IL
I
White
I
I
I
IC
(BD)
I
~-
I
I White I
intrabuilding
backbone
:Brown
HC
(FD)
I
X
I
Blue :
____
..,..
-
1
I
I
I
I
I
X
I
I Gray I
· ! - - - - - - · 1----I
------Second Ieveii
intrabuilding
I
backbone
I
I HC
I Gray I
I
I (FD)
I
X
I
,..
I
I IWhite lXI Blue ~
l ___ _
.
1
Color
1
X
= Termination field
= Cross-connect
~ = Telecommunications outlet/connector
HC (FD) = Horizontal cross-connect (floor distributor)
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD) = Main cross-connect (campus distributor)
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Support of Other Topologies
Certain systems are designed for topologies such as bus, ring, and tree. By using
interconnections and adapters in the ERs and TRs, these other logical topologies can be
accommodated within a star topology.
Logical bus, ring, and tree topologies that have been implemented using a physical star
topology are illustrated in Figures 4.18, 4.19, and 4.20.
Figure 4.18
Logical bus topology
MC (CD)
Y~~~-J ~Backbone
I
Bus
/ H C (FD)
//Horizontal
/
cabling
_.....--Work area
HC (FD) = Horizontal cross-connect (floor distributor)
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD) = Main cross-connect (campus distributor)
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Support of Other Topologies, continued
Figure 4.19
Logical ring topology implemented using a physical star topology
MC (CD)
HC (FD)
~/Horizontal
cabling
II\
I
I \
II\
I
I \
II\
I
I \
I \
I
000 000 000 O O 0 _....--work area
I
I
\
HC (FD) = Horizontal cross-connect (floor distributor)
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
Figure 4.20
Logical tree topology implemented using a hierarchical star topology
HC (FD)
I
I
I \
1
I
\
I
I \
1
I
\
I
I
1
\
I
\
I \
I \
/Horizontal
cabling
/
000 000 000 O 0 O --Work area
I
HC (FD) = Horizontal cross-connect (floor distributor)
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
© 2020 BICSI®
TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Support of Other Topologies, continued
To ensure that the backbone cabling can accommodate the voice and data transmission
protocols that are deployed by the customer, the TCT distribution designer should consider all
of the following:
• Length of the backbone segments
• Type of media used
• The customer's voice, data, and video networking equipment needs
• The customer's premises physical layout and overall area, including:
-Building layout (e.g., multistory, low-wide).
- Building construction (e.g., wood frame, steel structure, masonry).
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Telecommunications Rooms (TRs) and Telecommunications
Enclosures (TEs)
Overview
A TR is an enclosed architectural space for housing telecommunications equipment, cable
terminations, and cross-connect cabling. ATE is a case or housing for telecommunications
equipment, cable terminations, and cross-cmmect cabling. A TR or TE is a point where the
backbone cabling interfaces to the horizontal cabling.
NOTE: For information on where backbone cabling interfaces to horizontal cabling, see
Chapter 3: Telecommunications Spaces.
TRs or TEs also can accommodate devices that provide signal regeneration, signal
conversion, or other required signal processing (e.g., protocol conversion, encoding, data rate
translation). TRs or TEs also must accommodate backbone support hardware.
NOTE: Vertically align TRs in multi-story buildings whenever possible.
Additional Backbone Connections Between Telecommunications Rooms (TRs)
Direct connections between TRs are allowed if the backbone distribution system is expected
to meet the requirements for a bus topology or ring topology configuration. These direct
connections would be in addition to the connections for the star or hierarchical star topology.
Campus Backbone
The campus backbone cabling is the segment of a cabling system that presents the ICT
distribution designer and user with the most options, especially in a campus cabling
system. 'T'he campus backbone also is the cabling system segment most affected by physical
considerations (e.g., duct availability, right-of-way, physical barriers).
NOTES: For more detailed design information, refer to the latest edition of BICSI's
OSPDRM.
Information on building entrance facilities can be found in Chapter 3: Telecommunications
Spaces.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Buildi
Backbones
Overview
The design of a building backbone between the building cross-connect (main or intermediate)
and the HC (FD) is usually straightf01ward.
The two primary options are the:
• Star, where the HC (FD) is connected directly to the MC (CD).
• Hierarchical star, where some or all of the HCs (FDs) arc connected to an IC (BD), which in
turn, is connected to the MC (CD).
The two options are illustrated in Figures 4.21 and 4.22.
The best design is the star design between the MCs (CDs) building cross-connect and the
HCs (FDs ). However, in some extremely large buildings (e.g., high-rises), a hierarchical star
may be a consideration.
Examine trade-offs between different size cables and labor to determine a suitable costeffective solution. Applications may influence the decision.
Designing a building backbone involves the same options and decision processes that are
described in the campus backbone sections.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Overview, continued
Figure 4.21
Star building backbone
: ... ·~ ·.. :
MC (CD)
oriC(BD) r-------------------------------~
':
.·:
..".:
...
. ......... . . • ...
:,:
. .. : ,•, .· ... .: .
HC (FD) == Horizontal cross-connect (floor distributor)
IC (BD) == Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Overview, continued
Figure 4.22
Hierarchical star building backbone
rr:;:r : · ~. :·: ': :' ·:. ·:.~ ·.-.·. ':' ·...·.. -~ ·. . . :: .. _.:. -': :..... ': _:_ :'. <. . . . . : . . . : · ·:.:: ~- : ..:· ·:· ·=· ·: .... p-:;
•I
[5:
p=;=
-D
lr---D
P=:=
Jr---{
IC
(B~ f----[
I
I
I
I
I
I
I
~§
r;=c
(See Note)
~
ll____[
IL---D
~
c:;:r
¢c
a
Ire~ 1,-lc~L~
II
II
II
II
II
II
II
..
f----[
~
l____{
¢c
2I
?*
~
llr---t
¢c
II~~~ J--
11rIll
Ill
Ill
Ill
Ill
Ill
I
I
~
(See Note)
MC
(CD)
2I
(See Note)
IL___
?*
L-·--{]
0:::
¢c
EI
?*
l
I
I
O~HCs
I
h-1-r :: :_ :·: <.<:::- ·:·> ·:··. :.··~··::_.': .:.< ·''.:. .
:
,::,
~·
•:.::
(FDs)
~· ::::·':·
,:• '• '·.' •I
~
h=L
HC (FD) == Horizontal cross-connect (floor distributor)
IC (BD) == Intermediate cross-connect (building distributor)
MC (CD)== Main cross-connect (campus distributor)
NOTE: The same TR could house connecting hardware to serve the function of the IC (BD)
and HC (FD).
TDMM, 14th edition
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© 2020 BICSJ®
Chapter 4: Backbone Distribution Systems
Connecting Horizontal Cross-Connects (HCs [Floor Distributors (FDs)])
Avoid direct connections (e.g., tie cabling) between HCs (FDs). Although this kind of
pathway might be of value in providing a redundant path, a user should design a link from
HC (FD) to HC (FD) only in specific applications.
For redundancy, the preferred arrangement is illustrated in Figure 4.23.
Figure 4.23
Redundant routing for building backbone (HCs [FDs] not linked)
·.·.··.:··
•,
.·.·.-: ·'-
':
---------1
HC
(FD)
r-
~
~
.
I
- vi/?'8#/#~#/#//;;;a
:
1
---------
I
IHCl ____,l I
, - - - - - 1 HC
( FD)
I.Q'_I?j
- _ _ _ _ _ _-.r
1/?7/~~7~
~---
I
I
:
~-
-- - - -
lc~6ll
---
I
I
I
I
I - - -W/#/#~~::x~/#//~
I
I
1.-----1
I
I
I
I
I
I
I
I
I
I
I
I
I
1.-----1
I
II
1
I
I
I
I
I
I
I
1----,
I
II
II
~:~~~~~~-r---------------~J:
MC (CD)
-
-
-
-
-
-
-
oriC(BD)~~~~~~~~--------~
'. • • • •
---- =
-- - =
HC (FD) =
IC (BD) =
MC (CD)=
_:·'
::
\. :
< ::
:
~-
·: .... ·._.
Primary link
Redundant link
Horizontal cross-connect (floor distributor)
Intermediate cross-connect (building distributor)
Main cross-connect (campus distributor)
Figure 4.24 illustrates a typical backbone arrangement for an installation requiring both voice
and data system services at the user stations. A single backbone for each service connects the
TR on the Nth t-1oor to the MC (CD) in the ER. In practice, other backbones would extend
from the MC (CD) in a star like fashion to support other t-1oors and, if applicable, other
buildings.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Combined Optical Fiber and Balanced Twisted-Pair Backbone
Figure 4.24
Example of combined optical fiber/balanced twisted-pair backbone supporting voice and data traffic
Telecommunications room
----,
Nth Floor
Eo=~J[b 0 0 06~
Telecommunications
outlet/connectors
/
/Balanced twisted-pair
backbone (voice)
Optical fiber
backbone (data)
Equipment room
,-------,
Voice network
equipment
To/from
outside
services
[2J =
0
Termination hardware
= Equipment (optical fiber)
MC (CD)= Main cross-connect (campus distributor)
Often the most cost-effective transmission medium for:
• Data systems is optical fiber.
• Voice systems is balanced twisted-pair. Where remote telephone switch nodes or IP
telephones are deployed, optical fiber 1nay support voice systems.
Figure 4.24 shows a backbone arrangement that employs both technologies.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Equipment Rooms (ERs) and Access Provider (AP) Cabling System Interface
Cabling
Ideally, the MC (CD) would be co-located in the ER with a PBX, security monitoring
equipment, and other active equipment being served. However, this is not required and
physical constraints sometimes make co-location impossible (e.g., when the MC [CD] serves
multiple ERs that are not centralized). The location of the MC (CD) may be based entirely on
geographic and physical constraints (e.g., duct space, termination space).
A building cabling system shall have only one MC (CD). Connection to the ER can then
be provided by balanced twisted-pair or optical fiber, which is either in separate sheaths or
combined under a single sheath (see Figure 4.25).
Figure 4.25
ERs and AP cabling system interface cabling
ER,
MC (CD)
- - - = Access providers trunk cables
- - - = Backbone cables
ER = Equipment room
IC (BD) = Intermediate cross-connect (building distributor)
MC (CD)= Main cross-connect (campus distributor)
TR = Telecommunications room
For ultimate flexibility, manageability, and versatility of the cabling system, all backbone
cables and links to ERs should be terminated at the MC (CD). Each link can then be crossconnected to its ER on an as-needed basis by installing a patch cord, whether optical fiber or
balanced twisted-pair.
© 2020 BICSJ:®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Choosing Media
Overview
The choice of transmission media may depend upon the application. The factors to be
considered include the:
• Flexibility of the medium with respect to supported services.
• Required useful life ofbackbone cabling.
• Site size and user population.
• User needs analysis and forecast.
The telecommunications service needs of a commercial building's occupants will vary as time
passes and occupants change. Future uses ofthe backbone cabling may range from highly
predictable to unpredictable.
Whenever possible, determine the different service requirements first. lt is often convenient
to group similar services together in categories (e.g., voice systems, LAN, and other digital
connections). Then, identify the individual media types and projected quantities required
within each group.
When requirements are uncertain, use worst-case estimates to evaluate backbone cabling
alternatives. The more uncertain the requirements, the more tlexible the backbone cabling
system must be.
Each cable has individual characteristics that make it useful in a variety of situations. In some
situations, a single cable type may not satisfy all the user requirements. In these cases, use
more than one medium in the backbone cabling.
The different media should use the same physical topology within the same
telecommunications spaces for cross-connects, splices, and terminations.
Multimode Optical fiber Cable
OM4 or higher is recommended.
Singlemode Optical fiber Cable
Singlemode fiber is suitable for use with both analog and digital transmission.
100-0hm Balanced Twisted-Pair Copper Cable
The recommended balanced twisted-pair cable for building backbone consists of24 AWG
or up to 22 AWG round, solid copper conductors with a nominal characteristic impedance of
100 ohm.
TDMM, 14th edition
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© 2020 I.HCSI®
Chapter 4: Backbone Distribution Systems
Performance Categories for Multipair Backbone Balanced Twisted-Pair Cable
Multipair backbone balanced twisted-pair cable is specified in the following performance
categories:
• Category 3/Class C (specified up to 16 MHz)
• Category 5c/Class D (specified up to 100 MHz)
• Category 6/Class E (specified up to 250 MHz)
NOTES: Category 3 is available in 4 pair through 2700 pair configurations.
Category 5e is commonly available in 4 pair and 25 pair configurations. Sec
Chapter 6: TCT Cables and Connecting Hardware.
In addition to the ;:;::800 m (2625 ft) backbone cable length for voice systems, total length
between network equipment connections should not be greater than ~100m (328ft).
Advantages of Optical fiber Backbones for Campus Applications
The use of optical fiber in backbones for campus applications provides:
• The ability to support several different applications and both logical and physical topologies
because optical fiber offers:
- Applications supported over increased distances.
- High-speed data transmission rates.
- Immunity to lightning induced surges with all-dielectric sheath cables.
- Immunity to EMI and RFI.
-No crosstalk.
-No bonding requirement with all-dielectric sheath cables.
--Less pathway space required compared to copper cable.
• A properly planned system that anticipates growth and provides cabling system flexibility
and longevity for the following applications:
-Voice
Data
-Video
BAS (including ESS)
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Choosing Optical fiber Type
As a general guideline in premises applications for backbone cabling, optical fiber is
recommended to support multiple applications.
Often, a backbone comprised of both multimode and sing! em ode optical t1ber is
recommended to satisfy present and future needs in the backbone.
Always follow the OEM electronic equipment specifications for optical fiber core size when
designing an optical fiber telecommunications system.
Contact the OEM if:
• Specifications vary from OM3, OM4, OMS, OS la or OS2 optical fiber cable.
• The optical fiber is used for a unique application.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Backbone Building Pathways (Internal)
Vertically Aligned Telecommunications Rooms (TRs)
Vertically aligned TRs with connecting sleeves or slots are the most common type of
backbone pathway. They are desirable because the architect can stack them with other
mechanical spaces, and they make distribution of telecommunications cables more efficient
because of shorter conduits, bonding, and cabling runs.
NOTE: Ensure that proper firestop is maintained at all times (see Chapter 7: Firestop
Systems).
Conduits, Trays, Slots, Sleeves, and Ducts
Conduit Sizing
The metric designators and trade size references listed arc for identification purposes only and
arc not intended to represent actual dimensions. Table 4.3 shows the most common sizes of
conduits and their designations along with vernacular (where applicable) used in the industry.
Conduit is typically a raceway of circular cross-sectional area whose dimensions are based on
the ID but may also be made of duct or trough used to contain insulated conductors.
Table 4.3
Common conduit sizes with vernacular
Metric Designator
16
Vernacular
111111
21 m111
20
27mm
25
1/2
1/2 in
3/4
3/4 in
1-l/4
l-l/4 in
111111
40
l-1 /2
1-l/2 in
53 mm
50
2
2in
2-l/2
2-1/2 in
3
3 in
3-112
3-1/2 in
4
4 in
129111111
5
5 in
155111111
6
6in
63
111111
78 mm
75
91 mm
103mm
© 2020 BICSI®
Vernacular
1 in
3 5 111111
41
Trade Size
100
4-41
TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Conduits, Trays, Slots, Sleeves, and Ducts, continued
Three basic types of steel conduit in usc arc:
• RMC.
•IMC.
• EMT.
RMC is a threaded metal raceway of circular cross section with a coupling. Threads on the
uncoupled end arc covered by industry color-coded thread protectors, which:
• Protect the threads.
• Keep them clean and sharp.
• Aid in trade size recognition.
RMC is the heaviest-weight and thickest-wall steel conduit. When galvanized, it typically has
a coating of zinc on both the inside and outside. Galvanized RMC is noncombustible and can
be used indoors, outdoors, underground, concealed, or exposed.
When a design specifies vertical conduits with which vehicles may accidentally come into
contact (e.g., vehicle parking structures, storage and maintenance garages, sides of buildings,
utility poles), the ICT designer must specify that the section of conduit between the driving
surface and the highest point of accidental contact be galvanized RMC.
When a design specifies galvanized RMC sweeps at horizontal and vertical direction changes
of underground PVC conduit pathways, the designer must specify that the exterior of the
galvanized RMS sweeps be coated with an asphaltic compound prior to their installation to
prevent long term rust (e.g., PVC conduits to be installed under a concrete slab on grade,
prior to the concrete pour).
For special design considerations, when a design specifies RMC be buried underground, the
designer should consider specifying that the RMC be factory PVC coated inside and outside,
to prevent long term rust (e.g., PVC coated RMC to be installed on top of a solid concrete or
steel deck of a railway bridge, then covered with ballast rock).
The following guidelines should be considered. However, note that the actual sizes and colors
may vary by region:
• RMC is available in 16 through 155 metric designators ( l/2 through 6 trade sizes).
• RMC thread protectors are color coded based on trade sizes:
27, 53, 78, 103, 129, and 155 metric designators (1, 2, 3, 4, 5, and 6 trade sizes) are color
coded blue.
16, 41, 63, and 91 metric designators (112, 1-1/2,2-112, and 3-1/2 trade sizes) are black.
-21 and 35 metric designators (3/4 and 1-l/4 trade sizes) are red.
IMC is similar to RMC in that it also is a threaded metal raceway of circular cross section
with a coupling. Threads on the uncoupled end are covered by industry color-coded thread
protectors, which protect the threads, keep them clean and sharp, and aid in trade size
recognition.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Conduits, Trays, Slots, Sleeves, and Ducts, continued
IMC, however:
• Has a thinner wall thickness than RMC.
• Weighs about one-third less than RMC.
The outside of steellMC has a zinc-based coating, and the inside has an approved organic
corrosion-resistant coating. SteellMC is interchangeable with galvanized RMC. Both have
threads with a 19 mm (0. 75 in) per foot taper, use the same couplings and fittings, have the
same support requirements, and are permitted in the same locations.
TMC is available in 16 through I 03 metric designators (I /2 through 4 trade sizes). TMC thread
protectors are color coded based on trade sizes:
• 27, 53, 78, and 103 metric designators (1, 2, 3, and 4 trade sizes) are color coded orange.
• 16, 41, 63, and 91 metric designators ( l/2, 1-l/2, 2-l/2, and 3-112 trade sizes) are yellow.
• 21 and 35 metric designators (3/4 and 1-1/4 trade sizes) are green.
EMT, also commonly called thin-wall, is a steel raceway of circular cross section, which
is unthreaded. 'fhe outside corrosion protection is zinc based, and the inside features an
approved corrosion-resistant organic coating.
Setscrew or compression-type couplings and connectors are used to install EMT. They can
have an integral coupling that comprises an expanded, bell-shaped tube on one end with
setscrews. EMT with integral couplings is available in 63 through 100 metric designators
(2-1/2 through 4 trade sizes).
EMT is the lightest-weight metallic conduit manufactured. Although EMT is made of thinwalled metal, it provides basic physical protection and can be used in most exposed locations,
except where severe physical damage or hazardous environments are a possibility or
otherwise prohibited by the AHJ.
Sleeves or Slots
Position cable sleeves or slots adjacent to a wall on which the backbone cables can be
supported. Sleeves or slots must not obstruct wall-terminating space (i.e., they should not be
directly above or below the wall space that is to be used for termination fields).
NOTE: For additional information, see Chapter 3: Telecommunications Spaces.
Construct all:
• Slots and sleeves to conform to appropriate codes and standards.
• Slots with a minimum :::::;25.4 mm (I in) high curb.
• Sleeves to extend a minimum of;::c;25.4 mm ( l in) above the floor level and a maximum
of;::c;77 nun (3 in) above the floor level. Sleeves should be located a minimum of
:::::;25.4 mm (I in) from the wall or between adjacent sleeves to provide room for bushings,
but not so far from the wall that it would be a tripping hazard or create too great a cable
span from the sleeve to the backboard/tray.
© 2020 BICSI®
TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Sleeves or Slots, continued
NOTE: Ensure that proper firestop is maintained at all times (see Chapter 7: Fit·estop
Systems).
The quantity should be altered as necessary according to specific project needs or structural
limitations. They should also be coordinated with mechanical firestop systems.
Sleeve Quantity and Configuration
Use four I 03 metric designator (4 trade size) sleeves at a minimum from floor to floor as
a starting point to provide services. From that base of four sleeves, use one additional
103 metric designator (4 trade size) sleeve for each ::::-;3716 m 2 ( 40,000 ft 2) of useable floor
space served (e.g., from 1 to 40,000 ft2 would require 4 plus I, and 40,001 to 80,000 ft" would
require 4 plus 2). Figure 4.26 shows a six story building (plus a basement). Each of the six
floors has a useable area of ::::-;J716 m2 ( 40,000 ft 2). There are two riser systems, each serving
half of the useable area on each floor. Based on the serving equipment being in the basement
area (e.g., PBX, data), the figure indicates sleeves that should be provided in each riser
system.
Figure 4.26
Typical office building pathway layout
-----
-
6th Floor
'"
"-7s
mm (3 trade size)
conduit
5th Floor
4th Floor
103 mm ( 4 trade
conduit
size) _ /
"'
103 mm (4 trad e size)_/
sleeve
3rd Floor
y
•·
103 mm (4 trade size)_/
conduit
r
-Itt---·--
"'
~I I
103 mm (4 trad e size)_/
conduit
1st Floor
\
Main terminal/_/
equipment room
TDMM, 14th edition
2nd Floor
103 mm ( 4 trade size)
conduit
"'
4-44
Entrance room/_/
space
Basement
© 2020 BICSJ®
Chapter 4: Backbone Distribution Systems
Sleeves or Slots, continued
From the basement to the first floor, use seven sleeves (base of four plus three to serve
;:::;JJ,l48 m 2 [120,000 ff]).
From the first floor to the second floor, use seven sleeves (base of four plus three more to
serve ;:::;9290 m 2 [ l 00,000 ft 2]).
From the second floor to the third floor, use six sleeves (base of four plus two more to serve
;:::;7432 m 2 [80,000 ft 2J).
From the third floor to the fourth floor, use six sleeves (base of four plus two more to serve
;:::;5574 m 2 [60,000 ft 2]).
From fourth floor to fifth floor, use five sleeves (base of four plus one more to serve
;:::;3716 m 2 [40,000 ft2 ]).
From the fifth floor to sixth floor, use five sleeves (base of four plus one more to serve
;:::;J858 m 2 [20,000 ft 2 ]).
NOTE: With TRs aligned in a vertical pathway, some means for cable pulling should be
provided above and in line with the sleeves or slots at the uppennost room of each
vertical stack. A steel anchor pulling iron or eye embedded in the concrete is an
example. Similar techniques may be required for long building pathways.
When the number of sleeves or the area of the pathway requires more than one row of
sleeves, ICT distribution designers should restrict the number of rows to two wherever
practicable. A structural engineer shall approve the quantity, location, and configuration of
sleeves. For examples, see Figure 4.27.
Figure 4.27
Typical sleeve and slot installations
103 mm
( 4 trade size)
...
..
""'25 mm
(1 in)
Minimum
curb
""'254 mm (10 in)
Minimum
........._
Floor slot
© 2020 BICSJ:®
"'25-77 mm
(1-3 in)
___ _
I
/
Conduit sleeve through floor
4-45
TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Sleeves or Slots, continued
Slot Quantity and Configuration
Slots are typically located flush against the wall within a space and should be designed at
a depth (the dimension perpendicular to the wall) of;o:;l52 to 610 mm (6 to 24 in), giving
preference to narrower depths wherever possible. The location and configuration of the slot(s)
shall be approved by a structural engineer.
The size of the pathway using slots should be one slot sized at ;:::;0.04 m 2 ( 60 in 2) for up to
;:::;3716 m2 ( 40,000 ft 2) of usable floor space served by that backbone distribution system. The
slot area should be increased by ;:::;0.008 m 2 ( 12 in 2) with each ;:::;3 716 m2 ( 40,000 ftl) increase
in usable tloor space served by that backbone.
Open Cable Shafts
Open cable shafts are used when available and where large quantities of cables are required
on a floor that is distant from the main ER (e.g., the main ER is in the basement and a large
quantity of circuits are required on the 30th floor). Building managers normally direct cable
shaft use requirements.
Elevator Shafts
Do not locate backbone cable pathways in elevator shafts.
Enclosed Metallic Raceways or Conduits
Enclosed metallic raceways or conduits are also used as vertical and horizontal cable
pathways. These raceways or conduits:
• Sometimes are used to run cables PTP when intermediate splices or tenninations are not
required.
• Are not effective for general distribution purposes but do provide a high degree of security
and physical protection.
• Should be bonded to form a common bonding network.
NOTE: Vertical pathway runs may require the addition of pull boxes or similar means to
provide intermediate cable support capabilities.
Cable Trays
A cable tray can be used as a vertical cable pathway within shafts or as part of the pathway
between vertically aligned TRs. A cable tray can be open or covered and provides a means for
attaching vertical cable runs to the cable tray members.
NOTE: Consult with the cable tray manufacturer to determine suitable cable attachment
methodologies and limitations when considering the use of a cable tray as part of a
vertical cable pathway.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Miscellaneous Su
Facilities
Necessary Consultations
For backbone distribution systems, the ICT designer must check with the:
• Cable manufacturer for sheath strength characteristics, the maximum vertical rise distance
of the cable, and any specific installation guidelines.
• Building's licensed structural engineer for information about:
- Floor penetrations.
- Open cable shaft use.
- Building support beams and other structural elements where cable support, strands, and
other supporting hardware can be adequately anchored.
Cable that is improperly supported can cause:
• Slippage between the cable core and the sheath.
• Stretching of copper conductors and breakage of optical fiber strands.
• Broken cable, which can then fall through the pathway and damage other cables and
equipment or possibly result in personal injury.
NOTE: Vertical backbone cable pathways require the ICT distribution designer to consider
specific cable support requirements and methodologies, depending on the building
characteristics and the types of existing and proposed vertical pathways available to
the ICT distribution designer.
Supporting Strand
The use of vertical support strand should be considered where support of balanced twistedpair copper or fiber optic backbone cables is required within vertical pathways utilizing
shafts in multi-story buildings. Vertical support strand is an option when building height,
cable weights, or lack of access to intermediate support locations prevent other cable support
methods from being used.
With this method, the cable is fastened with clamps, ties, or other methods to a support strand
suspended between the highest floor of the building and the basement. The cable fasteners
are placed at the top of the run and at regular intervals along the strand as determined by the
maximum vertical rise distance for the cable being installed.
When considering the use of steel strand as a vertical support methodology, BfCSl 's
OSPDRM should be consulted for determining strand sizes, capacity, and installation
materials and methods. Since support strands must be adequately anchored to suitable
building supports, obtain a licensed structural engineer's review and approval for any
proposed anchoring and related 'support methodologies.
© 2020 BICSJ:®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Supporting Strand, continued
Where large, heavy, balanced twisted-pair backbone cables are used (e.g., 1200-pair copper),
clamp the cable to a support strand suspended between the highest floor of the building and
the basement.
Steel strands used for supporting riser cables are available in various sizes ranging from
;::;6.3 mm (0.25 in) to ;::;22 mm (0.87 in).
Insert cable ties (usually ;::;1.27 mm [0.05 in] steel) to secure backbone cable through the
layers of the strand before overall strand tensioning. Place the ties ;::;1 m (3.28 ft) apart with a
minimum of three ties per floor.
Other Methods for Securing Vertical Backbone Cable
Other methods to properly secure large, heavy backbone cables involve using:
• Brackets.
• Toggle bolts.
• Clamps that secure the cable to the plywood backboards in each TR or to intermediate
anchoring points within a cable shaft or pathways pull box.
• Steel cable ties.
• Straps (steel or plastic).
• Masonry anchors.
• A properly sized collar or mesh basket grip, which wraps around the whole cable and is
supported by a sleeve or slot opening or an anchoring point attached to a building structural
member.
Discuss these methods with the building's licensed structural engineer for approval before
adapting them to the construction plans.
WARNING: Vertical cable weight must be safely secured and managed during installation to
protect personnel from injury and prevent damage to the cable and other
equipment in the vicinity of the installation.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Bonding and Grounding (Earthing)
Proper bonding and grounding (earthing) is an essential element of a building backbone
distribution system.
NOTES: For fllliher details, see Chapter 8: Bonding and Grounding (Earthing). OSP bonding
and grounding (ea1ihing) procedures differ greatly from inside bonding and
grounding (eatihing). See the latest edition of BICSI's OSPDRM for additional
detail on OSP bonding and grounding (earthing).
Backbone Planni
Backbone cabling should be designed and installed to satisfy an entire site planning period or
anticipated life cycle.
Optical Fiber Strand Count
Optical fiber strand count is the number of optical fibers installed in the cable plant. 'fhe
strand count selected for a telecommunications cabling system impacts both the current and
future capabilities of the system.
Optical fiber is commonly used for almost all applications, including:
• Voice, data, security, BAS, and video telecommunications.
• Increased data rate telecommunications between peripheral devices.
• Increased distance transmission between existing balanced twisted-pair based cabling
system nodes.
As these applications and multi-user cabling systems have evolved, so have the concepts of
intelligent buildings and structured cabling systems.
As optical fiber applications and uses increase, a more sophisticated approach to cable plant
design is required. lCT distribution designers must not only plan for current needs, but also
for the evolution of future requirements.
Many of the individual optical fiber cable links installed today will be integrated into the
universal telecommunications cabling systems of tomorrow. Because future systems will
provide service for many different applications, the number of optical fibers installed into
today's backbone cables must be carefully considered.
In addition to present and future telecommunications requirements, an ICT distribution
designer must address optical fiber redundancy, system administration, and maintenance.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Optical Fiber Strand Count, continued
Criteria for Determining an Optical Fiber Strand Count
T'he decision regarding the number of optical fibers to install depends largely on the:
• Intended end-user application(s), both present and future.
• Level of multiplexing.
• Use of routers, servers, and switches.
• Physical topology of the cabling system.
• Cabling system configuration.
• Ease of adding future strands.
Sizing Optical Fiber Backbones
The most common application for optical fiber backbone cabling is multiplexed transmission.
In multiplexed transmission, multiplexing equipment in TRs and ERs combines signals from
many end points for transmission over two strands of optical fiber.
NOTE: For further information on multiplexed transmission, see Chapter 1: Principles of
Transmission.
When installing an optical fiber backbone, ensure that the cable includes enough optical fiber
strands to support all anticipated needs. Considerations include:
• Multiplexers:
- Number of strands needed to support the current equipment type.
• Spare optical fibers for:
- Maintenance.
- Redundancy.
- Segregated applications.
- Future applications.
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Indoor Hardware
Overview
Indoor hardware is more varied than outdoor hardware. Key points to consider are the
mounting and design.
Mounting Considerations
Indoor hardware is divided into two application areas based on the mounting location. These
application areas are:
• Rack mounted.
• Wall mounted.
Rack-Mounted Hardware
Rack-mounted hardware is installed in standard (:=:::483 mm [19 in] or ;:::584 mm [23 in])
cabinets or racks. Rack space is often available where telecommunications equipment is
installed, so this design is commonly used in:
• Data centers.
• ERs.
• Computer rooms.
• TRs.
Wall-Mounted Hardware
Wall-mounted hardware is used when rack space is not available or equipment must be
wall-mounted. Wall- and rack-mounted equipment may be used together.
Design Considerations
The three design factors to consider for indoor hardware are:
• Splicing hardware.
• Terminating hardware.
• Patch panels.
Fiber Splicing Hardware
Most indoor hardware is used for cable terminations. Since fiber pigtail splicing can be used
to terminate optical fibers, some cable terminating hardware accommodates indoor splice
points as well. Copper cable should not be spliced in TRs.
Splicing hardware is determined by:
• Mounting requirements.
• Optical fiber count.
• Splicing method.
© 2020 BICSJ:®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Design Considerations, continued
Terminating Hardware
Keep future growth in mind when designing:
• Cable terminating points located at cross-connections.
• Jumper length between patch panel and electronics.
Terminating hardware must be modular and flexible to meet future requirements for
additional cable or rearrangement.
To specify terminating hardware, the four factors that must be known are the:
• Location.
• Cable type.
• Termination method.
• Copper pair count or fiber strand count.
Patch Panels
Patch panels are recommended at termination points. The number of links terminated
determines the patch panel block space requirements. Additional space should be allocated to
patch panels so that growth after installation can occur gracefully.
The ICT distribution designer or installer should use patch panels at cross-connect locations,
such as:
• HCs (FDs).
• ICs (BDs).
• MCs (CDs).
A patch panel and cross-connect field is an administration point in the cable plant where the
cable is terminated in a panel that accepts patch cords and a cross-connect field with cords or
jumpers. Patch panels and cross-connect fields vary in size according to the number of cables
and terminations.
The cable plant should be interconnected to the applications equipment through the use of
patch cords. This method minimizes accidental damage to the backbone cable.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 4: Backbone Distribution Systems
Ethernet in the First Mile
Overview
EFM, also known as Ethernet to the last mile, describes the access network from the access
point to the subscriber's premise. The purpose of EFM and its distinction from traditional
Ethernet networks is to specify the functionality required for the subscriber access network
(e.g., public network access).
The network requirements of public networks versus private networks can be significantly
different. The private network is typically designed with knowledge of specific end
users' network utilization and throughput requirements where the access network must
service a broad range of end users running diverse applications with varying throughput
needs. Besides network utilization, other network design considerations that may be quite
different include the operation, administration, and maintenance function and environmental
factors.
The first mile is the critical connection between business and residential users and the public
network. Currently, homes and businesses have access to substantial bandwidth in their own
local area but are offered submegabit services.
Customer demand for Internet services has generated a proliferation of new types of
subscriber access networks and their underlying technologies. The challenge for EFM is to
enable effective Ethernet network designs for subscriber access networks that can deliver
quantifiable enhancements to current offerings at a reasonable cost, including both capital and
operating expenses.
Figure 4.28 illustrates the post divestiture telephone network boundaries with reference to
the last mile. The local exchange carrier serviced the local access and transport area, which
included the last mile (loop) and the interoffice trunks.
Figure 4.28
EFM network boundaries
Customer
premises
LEC
IEC
Inter-LATA
Loop
Interoffice
EB EB
Switch
1---F_e_ed_e_r_,
Trunk
1--T_o_ll_tr_u_n_k_-'+---•
LATA
boundary
IEC =
LATA=
LEC =
RT =
Interexchange carrier
Local access transport area
Local exchange carrier
Remote terminal
NOTE: In reference to Figure 4.28, the loop distance range is up to ::o;6.1 km (20,013 ft).
© 2020 BICSJ:®
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TDMM, 14th edition
Chapter 4: Backbone Distribution Systems
Ethernet in the first Mile (EFM) Physical layer Specifications
The Ethernet physical layer specifications contain the types of transmitters and receivers
and the functions that translate the data into signals (encoding) compatible with the cabling
type used (e.g., optical fiber, balanced twisted-pair, coaxial). The portion of the physical
layer responsible for interfacing to the transmission medium is called the physical medium
dependent sublayer.
The objective EFM physical layer specifications are provided in Table 4.4.
Table 4.4
Summary of EFM physical layer signaling systems
Rate Name
Nominal
Location
Span
(Mb/s)
l<m (mi)
Medium
I OOBASE-LX I 0
ONU/OLT
100
;::::;]0(6.2)
Duplex singlemode optical fibers
1OOBASE-BX I 0-D
OLT
100
;::::;10(6.2)
Simplex singlemode optical fiber
1OOBASE-BX 10-U
ONU
100
;::;:;] 0 (6.2)
Simplex singlemode optical fiber
1000BASE-LXIO
ONU/OLT
1000
;::::;] 0 (6.2)
Duplex singlemode optical fibers
;::::;0.55 (0.34)
Duplex multimode optical fibers
I OOOBASE-BX I 0-D
ocr
1000
;::::;] 0 (6.2)
Simplex singlemode optical fiber
IOOOBASE-BXlO-U
ONU
1000
;::;:;JO (6.2)
Simplex singlemode optical fiber
I OOOBASE-PX I 0-D PON
ocr
1000
;::;:;] 0 (6.2)
Simplex singlemode optical fiber
IOOOBASE-BXIO-U PON
ONU
1000
;::;:;t0(6.2)
Simplex singlemode optical fiber
I OOOBASE-PX20-D PON
ocr
1000
;::::;20(12.4)
Simplex singlemode optical fiber
I OOOBASE-BX20-U PON
ONU
1000
;::;:;20 ( 12.4)
Simplex singlemode optical fiber
IOPASS-T
NT/LT
Varies
Varies
One or more pairs of voice grade
balanced twisted-pair cable
2BASE-'fL
N'f/LT
Varies
Varies
One or more pairs of voice grade
balanced twisted-pair cable
LT =Line terminal
NT= Network terminal
OLT =Optical line terminal
ONU =Optical network unit
PON =Passive optical network
TDMM, 14th edition
4-54
© 2020 BICSI®
Chapter 5
Horizontal Distribution
Systems
Chapter 5 provides information concerning horizontal
distribution system concepts, methodologies, and
components. This chapter covers material regarding
simultaneous power and data transmission over
horizontal cabling and FTTO topologies, including
PoE.
Chapter 5: Horizontal Distribution Systems
Table of Contents
Horizontal Distribution Systems . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . 5-1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Horizontal Cabling Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Horizontal Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
General Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
SECTION 1: HORIZONTAL CABLING SYSTEMS
Horizontal Cabling Systems ..•............•.•..........••••.. 5-5
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Transmission Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Connection Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Permanent Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Horizontal Cross-Connect (HC [Floor Distributor (FD)]) . . . . . . . . . . . . . . . . . . . 5-10
Cross-Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
Interconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
Universal Connection Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Application-Specific Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15
Transition Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Bridged Taps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Splices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Horizontal Cabling Media . . . . . . . . • • • • . . . . . . . . . . . . . . . . . . . . . . . 5-17
Allowed Media Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Distances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Cable Slack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
Work Areas and Open Office Cabling .....•..•.••........•.•... 5-20
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
Telecommunications Outlet/Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20
Balanced Twisted-Pair Telecommunications Outlet/Connector . . . . . . . . . . . . 5-21
Optical Fiber Telecommunications Outlet/Connector . . . . . . . . . . . . . . . . . . . 5-22
Telecommunications Outlet Box Location Considerations . . . . . . . . . . . . . . . . 5-22
Work Area Equipment Cords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
© 2020 BICSI®
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Multiuser Telecommunications Outlet Assembly (MUTOA) . . . . . . . . . . . . . . . . . . 5-25
Multiuser Telecommunications Outlet Assembly (MUTOA) Design
Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
Locating Multiuser Telecommunications Outlet Assemblies (MUTOAs) ....... 5-29
Consolidation Point (CP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
Consolidation Point (CP) Design Considerations . . . . . . . . . . . . . . . . . . . . . . 5-30
Advantages and Disadvantages of the Consolidation Point (CP) . . . . . . . . . . . 5-32
Locating Consolidation Points (CPs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Wireless LAN (WLAN) Access Point (AP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-36
Simultaneous Data and Power Transmission within Horizontal
Cabling
Ill
Ill
Ill
•
Ill
ill
Iii
Iii
Iii
•
Iii
•
II
II
II
II
B
II
II
II
Ill
Ill
Ill
II
Ill
II
Ill
Ill
II
•
II
II
II
II
II
•
II
II
a
Ill
Iii
•
Iii
II
Ill
•
Ill
II
II
5-37
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37
Cabling Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37
Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38
Small Diameter Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-40
Cabling Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41
Authority Having Jurisdiction (AHJ), Codes, and Standards . . . . . . . . . . . . . . . . 5-41
Direct Current (de) Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-42
Power over Ethernet (PoE) Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-42
Power Source Equipment (PSE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
Endspan Power Source Equipment (PSE) . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
Midspan Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43
Centralized Optical fiber Cabling ..•.•............•.........•. 5-44
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
Centralized Optical Fiber Cabling Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-46
Centralized Optical Fiber Cabling Distances . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-46
Pull-Through Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-46
Interconnection and Splice Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-47
fiber-To-The-Outlet ( fTTO) ....•••........•••.•••.......•... 5-48
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-48
Traditional Structured Cabling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-49
Fiber-To-The-Outlet (FTTO) Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
Fiber-To-The-Outlet (FTTO) Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
Optical Fiber Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-50
Fiber Termination Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
Pre-terminated Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
Field Termination with Splice-On Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
Field Termination with Pre-polished Connector . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
TDMM, 14th edition
5-ii
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Horizontal Pathways for Fiber to the Office (FTTO) Systems ....•.. 5-53
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Work Area Outlet Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Design Considerations for FTIO Deployment . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Backbone Optical Fiber Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Horizontal Optical Fiber Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Telecommunications Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-54
Core and Distribution Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-54
Fiber-to-the-Office (FTIO) Installation Methods . . . . . . . . . . . . . . . . . . . . . . . . 5-54
Power and Cooling Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-54
Redundancy Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-54
Passive Optical Networks (PONs) .....•...........•••.......•. 5-56
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-56
Wave Division Multiplexing (WDM) Fundamentals . . . . . . . . . . . . . . . . . . . . . . . 5-58
Fiber Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-58
Enterprise Passive Optical Network (PON) Hardware Active Components
...... 5-58
Optical Line Terminal (OLT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-58
Optical Network Terminal (ONT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-59
Enterprise Passive Optical Network (PON) Hardware Passive Components ...... 5-59
Singlemode Optical Fiber and Connector Requirements . . . . . . . . . . . . . . . . 5-59
Passive Optical Splitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-60
Work Area Outlet Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-61
Design Considerations for Telecommunications Space-Based Optical Network
Terminal (ONT) Deployments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-61
Backbone Fiber Requirements and Terminations . . . . . . . . . . . . . . . . . . . . . 5-61
Horizontal Copper Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-61
Voice over Internet Protocol (VoiP) and Analog Voice Delivery . . . . . . . . . . . . 5-61
Radio Frequency (RF) Video Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-61
Desktop-Based Passive Optical Network (PON) Solution Architectures ......... 5-62
Telecommunications Spaces Requirements (Special Sizing Considerations) ... 5-62
Telecommunications Spaces Heating, Ventilation, and Air-Conditioning
(HVAC) Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-62
Horizontal Pathway Special Design Considerations . . . . . . . . . . . . . . . . . . . . 5-62
Horizontal Fiber Distribution Splitter Configurations . . . . . . . . . . . . . . . . . . . 5-62
Zone Cabling-Based Splitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-62
Planning for Future Dual Input Passive Optical Networks (PONs) and
Geographically Diverse Cable Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
© 2020 BICSI®
5-iii
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Power and Cooling Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
Typical Optical Line Terminal (OLT) Thermal Output and Cooling
Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
Desktop Optical Network Terminal (ONT) Remote and Backup Powering
Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
Optical Network Terminal (ONT) Battery Backup . . . . . . . . . . . . . . . . . . . . . 5-63
Campus-Based Outside Plant (OSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-64
Implementation Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-64
Administrative Record Keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-64
Testing and Certification of a Passive Optical Network (PON) Infrastructure ... 5-64
SECTION 2: HORIZONTAL PATHWAYS
Horizontal Pathways . .
~~
.
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.......
J;!l
•••••••
Ill
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5-65
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-65
Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-65
Sizing Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-66
Usable Floor Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-66
Maximum Occupant Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-66
Building Automation Systems (BAS) Density . . . . . . . . . . . . . . . . . . . . . . . . 5-66
Cabling Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-66
Cable Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67
Pathway Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67
Other Pathway System Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67
Telecommunications Outlets/Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67
Face Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67
Mounting Telecommunications Outlets/Connectors . . . . . . . . . . . . . . . . . . . . 5-67
Avoiding Electromagnetic Interference (EMI). . . . . . . . . . . . . . . . . . . . . . . . 5-68
Bonding and Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-68
Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-68
Firestopping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-68
Wet Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-69
Hazardous Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-69
Types of Horizontal Pathways ........•.......••.•.••••.••.•. 5-70
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-70
Conduit Distribution Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-70
Suitability and Acceptability of Conduits . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-71
Conduit Body. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-72
Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-73
Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-79
TDMM, 14th edition
5-iv
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Bend Radii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-80
Conduit Terminations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-81
Completing Conduit Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-81
Pull Points and Pull Boxes for Conduits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-82
Choosing a Pull Box Size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-83
Slip Sleeves and Gutters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-84
Underfloor Conduit Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-85
Access Floor Distribution Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 5-85
Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-85
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-86
Stringered Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-86
Freestanding and Cornerlock Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-87
Considerations for Access Floor Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-87
Minimum Finished Floor Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-87
Building Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-88
Building Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-89
Floor Penetrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-89
Bonding and Grounding (Earthing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-89
Floor Panel Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-89
Floor Panel Coverings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-90
Load-Bearing Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-90
Specifying Access Floor Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-91
Electrical Power Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-91
Effects of Underfloor Air Distribution on Cabling . . . . . . . . . . . . . . . . . . . . . . . . 5-91
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-92
Ceiling Distribution Systems . . . . . . . . . . . . . • • . . . . . . . . . • . . . . . . . • 5-93
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-93
Acceptable Methods of Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-93
General Design Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-93
Determining Adequate Ceiling Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-94
Selection of Ceiling Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-94
Restrictions on Ceiling Cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-95
Ceiling Zones Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-95
Pathway and Cable Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-98
Termination Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-99
Connecting Hardware in Ceiling Space . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-100
Overhead Ceiling Enclosed Raceway Method . . . . . . . . . . . . . . . . . . . . . . . 5-100
Overhead Ceiling Raceways and Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . 5-101
Utility Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-101
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-104
© 2020 BICSI®
5-v
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Cable Tray Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-105
Types of Cable Trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-105
Cable Tray Fittings and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-106
Cable Tray Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-106
Cable Tray Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-108
Supporting Cable Trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-108
Bonding and Grounding Cable Trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-108
Conduit and Raceway Distribution Design . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-109
Ceiling Home-Run Method Using Conduit . . . . . . . . . . . . . . . . . . . . . . . . . 5-109
Zone Conduit Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-109
Other Horizontal Pathways ....••••.......•••...........••.. 5-110
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-110
Messenger or Support Strand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-110
Perimeter Pathways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-110
Perimeter Raceways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-111
Molding Raceways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-113
Open Office Modular Furniture and Partition Pathways. . . . . . . . . . . . . . . . . . . 5-114
Poke-Thru . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-116
SECTION 3: ADA REQUIREMENTS
Americans with Disabilities Act (ADA) Requirements ........••.. 5-117
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-117
Americans with Disabilities Act (ADA) Existing Facilities Rule . . . . . . . . . . . . . . 5-118
Readily Achievable Removal of Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-118
Alterations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-118
New Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-118
Public Telephones and Text Telephones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-119
Americans with Disabilities Act (ADA) Height Requirements . . . . . . . . . . . . . . . 5-120
Text Telephones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-123
Volume Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-123
Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-124
Appendix: Disabled Access and the Americans with Disabilities
Act (ADA)
Ill
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Americans with Disabilities Act (ADA): A Civil Rights Law . . . . . . . . . . . . . . . . . 5-125
Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-125
TDMM, 14th edition
5-vi
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
figures
Figure 5.1
Typical horizontal cabling system elements
5-2
Figure 5.2
Horizontal cabling system channel . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Figure 5.3
Horizontal cabling system channel model with four connection points ... 5-8
Figure 5.4
Horizontal cabling system channel model with three connection points .. 5-9
Figure 5.5
Horizontal cabling system permanent link model with three
connection points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
Figure 5.6
Example of connection by means of cross-connection . . . . . . . . . . . . . 5-12
Figure 5. 7
Figure 5.8
Example of connection by means of interconnection . . . . . . . . . . . . . . 5-13
Example of connection by means of cross-connection and
interconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Figure 5.9
Figure 5.10
Example of connection by means of double cross-connection ........ 5-15
Total cable length in the horizontal cabling system channel ......... 5-18
Figure 5.11. Pin/pair assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
Figure 5.12 Typical dimensions for furniture opening for telecommunications
faceplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
Figure 5.13
Example of MUTOA application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
Figure 5.14
CPs used in a combined furniture system and private office work
area environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30
Figure 5.15
CPs located on all columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33
Figure 5.16
CPs located in a space between the columns . . . . . . . . . . . . . . . . . . . 5-34
Figure 5.17
CPs located in checkerboard order . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35
Figure 5.18
CPs located on columns close to the building core . . . . . . . . . . . . . . . . 5-36
Figure 5.19
Temperature versus wattage for category cable types
Figure 5.20
Insertion loss versus temperature for category cable types ......... 5-39
Figure 5.21
Centralized optical fiber cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45
Figure 5.22
Traditional structured cabling LAN design compared with FTTO LAN ... 5-49
Figure 5.23
Traditional active Ethernet design compared with PON-based
architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-56
Figure 5.24
Underfloor conduit extended to individual telecommunications outlet
boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-70
Figure 5.25
Typical underfloor conduit system . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-71
Figure 5.26
Conduit bodies recommended for telecommunications cables ........ 5-72
Figure 5.27
Recommended pull box configurations . . . . . . . . . . . . . . . . . . . . . . . . 5-82
Figure 5.28
Stringered access floor system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-86
Figure 5.29
Recommended clearance for access floor spaces . . . . . . . . . . . . . . . . . 5-88
Figure 5.30
Typical zoned ceiling (plan view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-96
Figure 5.31
Conduit-based ceiling zone (elevation view) . . . . . . . . . . . . . . . . . . . . 5-97
Figure 5.32
Rules of installation for discrete cable support facilities . . . . . . . . . . . . 5-99
© 2020 BICSI®
5-vii
. . . . . . . . . . . . 5-38
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Figure 5.33
Raceways and fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-101
Figure 5.34
Attaching various utility columns . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-103
Figure 5.35
Perimeter raceway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-112
Figure 5.36
Molding raceway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-113
Figure 5.37
Side-reach telephones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-121
Figure 5.38
Forward-reach telephones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-122
Figure 5.39
International teletypewriter/text telephone symbol and volume
control telephone symbol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-124
TDMM, 14th edition
5-viii
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Tables
Table 5.1
Maximum allowable cable lengths with the use of multiuser
telecommunications outlet assemblies . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Table 5.2
Comparison of CP locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32
Table 5.3
PoE and HDBaseT current specifications . . . . . . . . . . . . . . . . . . . . . . . 5-37
Table 5.4
Primary PON variations and their source standards . . . . . . . . . . . . . . . 5-57
Table 5.5
Maximum channel attenuation and supported distance for PON
versions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-60
Table 5.6
EMT 40 percent conduit fill rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-74
Table 5. 7
Typical EMT conduit fill rate for varying cable diameters . . . . . . . . . . . . 5-75
Table 5.8
Conduit fill with 1 bend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-76
Table 5.9
Conduit fill with 2 bends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-77
Table 5.10
Bend radii guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-80
Table 5.11
Adapting designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-81
Table 5.12
Typical space requirements for pull boxes having conduit enter at
opposite ends of the box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-83
Table 5.13
Slip sleeves and gutters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-84
Table 5.14
Coverings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-90
Table 5.15
Load capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-90
Table 5.16
Guidelines for recommending ceiling panels . . . . . . . . . . . . . . . . . . . . 5-94
Table 5.17
Common types of cable trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-105
Table 5.18
Common cable tray dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-107
Table 5.19
ADA height requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-120
© 2020 BICSI®
5-ix
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Horizontal Distribution Systems
Introduction
This chapter has three sections. The cabling and pathway components of the horizontal
distribution system are covered in the first two sections with the third section discussing
accessibility requirements for those with disabilities.
A horizontal distribution system consists of the horizontal cabling, the horizontal pathways
supporting the horizontal cabling, and the telecommunications spaces that support the
horizontal pathways. Section I of this chapter covers horizontal cabling while Section 2
covers horizontal pathways and their related spaces.
As horizontal distribution systems, cabling, and pathways often change direction, elevation,
or physical orientation to accommodate obstructions, barriers, and other building systems, the
use of the term horizontal in the name of the element does not require that the elements be
placed or installed parallel to the ground or floor.
Horizontal Cabling Systems
A horizontal cabling system may be as simple as the cabling necessary to support a small
number of telecommunication outlets for a small business to the cabling infrastructure
required to support a floor of a hospital or an airport terminal.
A horizontal cabling system may include the following clements:
• Work area equipment cord
• Work area connecting hardware:
- ·releconununications outlets/connectors
-MUTOAs
• Horizontal distribution cables
• HC (FD) connecting hardware (e.g., wiring blocks, patch panels)
• Jumpers and patch cords used to configure horizontal cabling connections at the HC (FD)
• Equipment cords at the HC (FD) typically located in the ER TR, or TE
• Additional elements (connectors that may be installed between the telecommunications
outlet and the HC [FD]):
-TP
-CP
Within horizontal cabling, each implementation is different and may use some or all of the
elements listed above. Figure 5.1 shows the horizontal cabling elements that are commonly
used.
© 2020 BICSI®
5-1
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Horizontal Cabling Systems, continued
Figure 5.1
Typical horizontal cabling system elements
Equipment cord
ER/TR/TE
Ceiling space
------~-------
WAP
Equipment cords
Work area
Horizontal cable
M
Work area
ILl-----H-i u
T
P;\"<!9'-----H-1
0
f-----'
A
Work area
CP
Horizontal cable
Horizontal cable
Equipment
CP =
ER =
HC (FD) =
MUTOA =
TE =
TO=
TR =
WAP =
Consolidation point
Equipment room
Horizontal cross-connect (floor distributor)
Multiuser telecommunications outlet assembly
Telecommunications enclosure
Telecommunications outlet/connector
Telecommunications room
Wireless access point
NOTE: The images of connecting hardware and active equipment used in this chapter have
been selected for the purpose of illustrating the text and should not be construed as
requirements. For example, a generic patch panel image may represent any type of
balanced twisted-pair or optical fiber connecting hardware; an image of a server may
represent any type of active equipment.
TDMM, 14th edition
5-2
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Horizontal Pathways
Horizontal pathways are used for distributing, supporting, and providing access to
horizontal cabling and its associated connecting hardware between the telecommunications
outlets/connectors and the HC (FD), typically located in the ER, TR, or TE. Horizontal
cabling are the media contained within horizontal pathways.
Pathway system implementation involves the cabling pathways (e.g., cable tray, conduit) and
the locations of related telecommunications spaces (e.g., TRs, TEs) that provide access to
cabling or connecting hardware.
Horizontal pathways are of one of two general types:
• Continuous pathways (e.g., conduit, cable tray) used for uninterrupted support and
management of telecommunications cabling.
• Non-continuous pathways (e.g., the space between cable supports [e.g., J-hooks]) through
which cables are placed between physical supports or containment components.
Elements such as pull boxes or splice boxes, which are used with some pathway systems, are
actually considered telecommunications spaces that provide access to horizontal cabling and
its connecting hardware.
General Design Considerations
The design methodologies offered in this chapter for horizontal distribution systems are based
on current best practices and standards for general and commercial building. The principles
for horizontal distribution systems are also used for non-commercial building applications
(e.g., health care and industrial facilities), but these applications may have additional
requirements or restrictions that need to be considered.
Generally, cabling system choices should not dictate cabling pathway choices. The goal of
a pathway component is to accommodate all standards-compliant cabling and the potential
need for change during the life cycle of the cabling system and building.
Additionally, as cabling system renovations (e.g., MACs) are a common occurrence within
horizontal distribution, anything that can be done at the design stage to reduce the unit change
time and cost (e.g., materials, labor, occupant disruption) may significantly reduce the overall
life cycle maintenance and operational costs of a horizontal distribution system.
Therefore, the ICT distribution designer should focus first on the pathway systems design and
then on the cabling systems design. This strategy helps to ensure a robust pathway system
that supports the cabling installation over the facility's life cycle.
© 2020 BICSI®
5-3
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
General Design Considerations, continued
Therefore, the ICT distribution designer should ensure that the horizontal distribution
system's design:
• A11ows for the accommodation of change over the facility's life cycle with the goal of
reducing long-term maintenance and operational costs.
• Utilizes standardized cabling, components, and systems.
• Includes appropriate pathway and cabling components to accommodate ease of access and a
variety of user specified technology applications.
• Meets or exceeds all codes, standards, regulations, and AHJ rulings.
• Meets the requirements and utilizes any applicable standards or recommendations in this
chapter that do not conflict with applicable codes or regulations.
NOTE: For a list of regulatory requirements, refer to Appendix A: Codes, Standards,
Regulations, and Organizations in this manual.
As horizontal cabling is part of the overall telecommunications infrastructure, other chapters
of this manual that have additional requirements affecting the design of horizontal distribution
systems include:
• Chapter 3: Telecommunications Spaces.
• Chapter 4: Backbone Distribution Systems.
• Chapter 8: Bonding and Grounding (Earthing).
• Chapter 10: Telecommunications Administration.
• Chapter 11: Field ·resting of Structured Cabling.
TDMM, 14th edition
5-4
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Horizontal Cabling Systems
Overview
The horizontal cabling system is the part of the telecommunications cabling that extends
from the work area telecommunications outlets/connectors to the 1-IC (FD), typically located
in the floor-serving TR or TE. The horizontal cabling system consists of horizontal cables,
telecommunications outlets/connectors in the work area, mechanical terminations, work area
equipment cords, network equipment cords, and other patch cords or jumpers located in the
TR and may include MUTOAs, CPs, and TPs.
The horizontal cabling system should be designed in order to support various
telecommunications applications, including:
• Voice services.
• Data services.
• Audio and video services.
• Building signaling systems (e.g., BAS, fire, security).
As horizontal cabling is often less accessible than backbone cabling, making changes can
become time intensive or expensive. Frequently accessing or changing the horizontal cabling
leads to disruption to occupants; therefore, the choice and layout of horizontal cabling types
are important to the design of the building structured cabling system.
As a result, horizontal cabling should be planned to satisfy today's telecommunications
needs and reduce ongoing maintenance and relocation as well as accommodate future user
applications and active equipment and service changes.
© 2020 BICSI®
5-5
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Topology
Horizontal cabling shall be installed in a physical star topology. Each telecommunications
outlet/connector shall be cabled directly to an HC (FD) in the appropriate telecommunications
space.
Three exceptions to this practice are when:
• A CP or MUTOA is used to connect to open office cabling.
• A TP is required to connect to undercarpet cabling.
• Centralized optical fiber cabling is implemented from MC (CD) to the work area(s).
NOTE: For additional details, see Centralized Optical Fiber Cabling in this chapter.
Some applications may utilize a bus, ring, or tree topology, which can be implemented
within a physical star topology. For examples, see the Backbone Topologies section in
Chapter 4: Backbone Distribution Systems.
Configuration
In determining the horizontal cabling system configuration, it is assumed that the typical
telecommunications applications in commercial buildings are voice and data transmission
applications. Thus, the minimum configuration is the configuration consisting of two
telecommunications outlets/connectors in the work area-one for telephony and the other for
data. It is recommended that the system be planned with a margin exceeding this minimum
requirement.
If the optical fiber outlet is used in the horizontal cabling system work area configuration,
then two balanced twisted-pair telecommunications outlets/connectors should also be
installed rather than one since typical telecommunications cabling work areas currently
require both voice and data transmission, which are usually implemented over balanced
twisted-pairs. Thus, the work area configuration made up of only two telecommunications
outlets/connectors, one of which is optical fiber, may not allow all user requirements for
telecommunications services to be effectively met.
TDMM, 14th edition
5-6
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Transmission Channel
Within horizontal cabling, the transmission channel is the end-to-end transmission path
between two points at which application-specific equipment is connected. This channel is
composed of:
• The permanent link cabling.
• Required patch, equipment, and interconnection cords.
• The connection points.
Figure 5.2 shows the basic channel model.
Figure 5.2
Horizontal cabling system channel
TO
lc:;JI
HC (FD)
Work area
TR
Work area
Work area
Work area
Work area
CD =
Permanent link cabling
@ = Work area equipment cord
HC (FD) = Horizontal cross-connect (floor distributor)
TO= Telecommunications outlet/connector
TR = Telecommunications room
© 2020 BICSI®
5-7
TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Transmission Channel, continued
Connection Points
A maximum of four connection points (four connectors) are allowed in the channel model:
• Telecommunications outlet/connectors or MUTOAs
• Connector of the first unit of connecting hardware at the HC (FD)
• CP connector (optional)
• Connector of the second unit of connecting hardware at the HC (FD)
Figure 5.3 illustrates a horizontal cabling system channel model with four connection points
utilizing a consolidation point. It consists of a patch cord between equipment patch panel and
horizontal cable panel (two connections), CP and telecommunications outlet (one connection
each) for a maximum total of four connections.
Figure 5.3
Horizontal cabling system channel model with four connection points
TR
Connections
®
®
©
Cabling
Active equipment
(D
Interconnect equipment cord (single port)
Patch panel/termination hardware
0
Cross-connect patch cord (MC, IC, or HC) (single port)
Telecommunications outlet/connector (TO)
@
Consolidation point (CP)
®
0
Multiuser telecommunications
outlet assembly (MUTOA)
(D
G)
Interconnect equipment cable (multi port/circuit)
Horizontal cable
® Backbone cable
Horizontal connection point (HCP)
TDMM, 14th edition
5-8
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Transmission Channel, continued
Common channel configurations with three connection points are illustrated in Figure 5.4.
It consists of a horizontal patch panel, consolidation point, and telecommunications outlet.
Alternately, an equipment patch panel, horizontal cable patch panel, and telecommunications
outlet.
Figure 5.4
Horizontal cabling system channel model with three connection points
TR
)
Connections
0
®
©
Cabling
Active equipment
(D
Interconnect equipment cord (single port)
Patch panel/termination hardware
0
Cross·connect patch cord (MC, IC, or HC) (single port)
Telecommunications outlet/ connector (TO)
@
Consolidation point (CP)
®
0
Multiuser telecommunications
outlet assembly (MUTOA)
G)
G)
0
Interconnect equipment cable (multi port/ circuit)
Horizontal cable
Backbone cable
Horizontal connection point (HCP)
Permanent Link
Within the channel, the permanent link extends from the HC (FD) to the telecommunications
outlet/connector. Within the permanent link, no more than three connection points
(i.e., connecting hardware) are allowed. As the HC (FD) and telecommunications
outlet/connector are each a required connection, this allows no more than one CP to be
placed in the permanent link.
© 2020 BICSI®
S-9
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Transmission Channel, continued
Figure 5.5 illustrates a permanent link utilizing a CP.
Figure 5.5
Horizontal cabling system permanent link model with three connection points
TR
I:::::
0
:= =: ##-]
i(D
DM~~l---~-----c;_--~--9?j:~
\,_
Connections
0
®
©
Permanent link
Cabling
Active equipment
(D
Interconnect equipment cord (single port)
Patch panel/termination hardware
0
Cross-connect patch cord (MC, IC, or HC) (single port)
Telecommunications outlet/connector (TO)
@
Consolidation point (CP)
®
0
Multiuser telecommunications
outlet assembly (MUTOA)
~
G)
G)
®
Interconnect equipment cable (multi port/circuit)
Horizontal cable
Backbone cable
Horizontal connection point (HCP)
Horizontal Cross-Connect (HC [Floor Distributor (FD)])
Two methods of connecting active equipment to the horizontal cabling system and one
method for passive connection between the horizontal and backbone systems are used in the
HC (FD). These two methods are known as cross-connection and interconnection.
Cross-Connection
Cross-connection is a method where two connecting hardware units
(e.g., balanced twisted-pair, optical fiber) are linked by patch cords or cross-connect
jumpers and used to connect active equipment to the horizontal cabling system. The passive
connection of cabling segments of the horizontal and backbone systems are also known as
cross-connections.
In the HC (FD), the cross-connection method shall be applied to connect active equipment
with balanced twisted-pair individual port (e.g., 4-pair) or multi port (e.g., 25-pair) connectors
to the horizontal cabling system and to provide passive connection between cabling segments
of the horizontal and backbone systems.
NOTE: Balanced twisted-pair multipart connectors are connectors with more than eight
contacts (four pairs), which can be logically grouped and assigned different network
addresses (ports). The most common and widely used balanced twisted-pair multi port
connector is a 50-position miniature ribbon connector (also known as a 25-pair
telephone company [RJ-21] connector).
TDMM, 14th edition
5-10
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Horizontal Cross-Connect (HC [Floor Distributor (FD)]), continued
Details on the 50-position miniature ribbon (RJ-21) connectors can be found in
Chapter 6: ICT Cables and Connecting Hardware.
The following methods may be used to connect the active equipment with RJ-21 connectors
to the cabling system:
• Termination of active equipment cord pairs directly onto connecting hardware
(e.g., connecting blocks, patch panels) connectors using cables pre-terminated with a
connector on the equipment end and unterminated on the hardware end.
• Using special-purpose connecting hardware with pre-terminated (factory installed)
RJ-21 connectors, using cables with pre-tenninated connectors on both ends of the cable.
• Using connecting hardware with modular connectors (e.g., patch panels) and hybrid patch
cords (e.g., hydra or octopus cable assemblies) with an RJ-21 connector on one side and
several modular plugs on the other.
When connecting active equipment with single-port connectors to the cabling system
(e.g., up to eight contacts [four pairs] or optical fiber), the cross-connection method is
typically not used because single-port equipment cords may be applied as interconnections.
This provides the same simple and flexible connection as the cross-connection method while
saving one additional unit of connecting hardware with cross-connect patch cord assembly.
If single-port connector active equipment should be connected to the cabling system using the
cross-connection method, then any of the three methods described above may be used.
NOTE: It is recommended that the HC (FD) be located on the same floor as the work area it
serves.
Interconnection
Interconnection is a method of connecting the horizontal cable to the active equipment.
The horizontal cable is terminated on the connecting hardware (e.g. patch panel) and an
equipment cord is used to interconnect the connecting hardware to the active equipment.
Interconnection is allowed in the horizontal cabling system to connect active equipment with
single-port (e.g., up to eight contacts [four pairs] or optical fiber) connectors to the horizontal
cabling system.
Connection of active equipment with single-port connectors to the cabling system by means
of interconnection and cross-connection enables a flexible and efficient switching scheme.
If the interconnection is used, then there is no need to use the second unit of connecting
hardware and additional patch cord assembly in the horizontal cabling system.
An additional benefit of the interconnection method is the saving of valuable wall or
rack/cabinet mounting space.
NOTE: Single-port connectors may be 8P8C modular connectors such as those used in the
RJ-45-type or optical fiber connectors. Details on the balanced twisted-pair and
optical fiber connectors can be found in Chapter 6: ICT Cables and Connecting
Hardware.
© 2020 BICSI®
5-11
TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Horizontal Cross-Connect (HC [Floor Distributor (FD)]), continued
Interconnection is not allowed in the HC (FD) to enable passive connections between cabling
segments of the horizontal and backbone systems except when the centralized optical fiber
topology is used.
NOTE: Details on centralized optical fiber cabling topology can be found in the Centralized
Optical Fiber Cabling section of this chapter.
Universal Connection Rules
Figure 5.6, Figure 5.7, Figure 5.8, and Figure 5.9 show examples of various configurations
of building horizontal cross-connection and interconnection with different types of active
equipment used and their respective connection requirements.
The example in Figure 5.6 demonstrates the active equipment interconnection (3) in the
ER. Using an RJ-21 connector interface to the active equipment (e.g., data switch). The
passive main cross-connection (2) of the backbone cabling system (5), and the equipment
interconnection cable (3) in the ER. The cross-connection between the backbone cabling (5)
and the horizontal cabling system (4) at the HC (FD) in the TR is another example of the
requirement for a cross-connection.
Figure 5.6
Example of connection by means of cross-connection
ER/MC
: Work area
TR
i© CD 0
~~~-~
~am~~:~~~
I
L____________ ___ _________
Connections
0
®
Acti ve equipment
@
@
Telecommunications outlet/ connector (TO)
®
®
Multiuser telecommunications
outlet assembly (MUTOA)
Patch panel/termination hardware
Consolidation point (CP)
!
I
~
~
L____________________________ J
Cabling
(D
G)
G)
0
0
Interconnect equipment cord (single port)
Cross-connect patch cord (MC, IC, or HC) (single port)
Interconnect equipment cable (multi port/ circuit)
Horizontal cable
Backbone cable
Horizontal connection point (HCP)
TDMM, 14th edition
5-12
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Horizontal Cross-Connect (HC [Floor Distributor (FD)]), continued
The example in Figure 5. 7 demonstrates the connection of active equipment using all
interconnections. Using single-port connections by means of interconnection in the ER of
server equipment to the backbone cabling system (5) and in the TR interconnections between
the backbone cabling (5), patch panel (B), and active equipment (A), and between active
equipment (A) and the horizontal cabling (4) patch panel (B).
Figure 5.7
Example of connection by means of interconnection
r---------------------------------,
I
I
:
ER/MC
:
I
I
I
I
I
I
I
I
I
I
i0
i
cv
®
i®
Irr8Mliiiiiii~l~
m
I
I
I
I
I
I
I
I
I
I
L---------------------------------~
Connections
Cabling
Active equipment
Q)
Interconnect equipment cord (single port)
®
Patch panel/termination hardware
0
Cross-connect patch cord (MC, IC, or HC) (single port)
@
@
Telecommunications outlet/connector (TO)
®
Multiuser telecommunications
outlet assembly (MUTOA)
0
Horizontal connection point (HCP)
@
Consolidation point (CP)
G)
G)
Interconnect equipment cable (multi port/circuit)
Horizontal cable
® Backbone cable
The example in Figure 5.8 shows the connection of active network equipment in the ER is
made with single-port optical fiber connectors (uplink) (1) to the backbone system (5) by way
of interconnection (1 ). In the TR, there is an interconnection between the backbone cabling
(5) panel (B) and the equipment (A). There is a multipart interconnection with multipart
RJ-21 connectors (downlink) (3) to the equipment patch panel. The horizontal cabling
system (4) is connected to the equipment patch panel (B) by way of cross-connection (2 HC).
© 2020 BICSI®
5-13
TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Horizontal Cross-Connect (HC [Floor Distributor (FD)]), continued
Figure 5.8
Example of connection by means of cross-connection and interconnection
:-ERtM-c-------------------------1
I
I
I
I
I
I
I
I
I
I
:0
A
:
I
I
I
I
I
I
I
I
I
I®
5
I
I
I
I
I
I
o
1
I
I
r-----------------------------------~
: TR
I
I
=-.--------------,~
I
I
I
I
I
--r-
1
I
I
I
~
I
I
I
I
I
I
I
I
I
I
I
I
I
I
~--------------------------------4
I
I
~-----------------------------------4
Connections
Cabling
Active equipment
(D
Interconnect equipment cord (single port)
®
Patch panel/termination hardware
0
Cross-connect patch cord (MC, IC, or HC) (single port)
©
Telecommunications outlet/connector (TO)
G)
Interconnect equipment cable (multi port/circuit)
®
®
Consolidation point (CP)
@
0
Multiuser telecommunications
outlet assembly (MUTOA)
0 Horizontal cable
® Backbone cable
Horizontal connection point (HCP)
The example in Figure 5.9 demonstrates the use ofMC (CD), IC (BD), and HC (FD). The
interconnection of active equipment (PBX)( A) using equipment cable (3) with multi port
RJ-21 connectors to the equipment patch panel in the ER. The MC (CD) cross-connection of
the equipment patch panel (B) to the backbone cabling system (5) patch panel (B) by means
of cross-connection (2 MC). InTR-A the first level backbone cable (5) patch panel (B) is
cross-connected (2 IC) to the 2nd level backbone cable (5) patch panel (B). In TR-B the
backbone cable (5) patch panel (B) is cross-connected (2) to the horizontal cable (4) patch
panel (B).
TDMM, 14th edition
5-14
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Horizontal Cross-Connect (HC [Floor Distributor (FD)]), continued
Figure 5.9
Example of connection by means of double cross-connection
ER/MC
r----------------~
: TR-B
TR-A
:
I
I
:
I
I
I
~-----------------------
Connections
)
I
®
Work area
l
: -D ~
-~ --~1
i
I:
{,\
:1©
0HC
Q
: c~~~-+1-J
a i i i a ri&EI ~--i<:.<J.
I
~------ - -------------------------- ~
:
I
I
®
~--------- - --------------
Cabli ng
0
®
Active equipment
@
@
Telecommunications outlet/ connector {TO)
®
®
Multiuser telecommunications
outlet assembly {MUTOA)
Patch panel/termination hardware
Consolidation point (CP)
(D
@
G)
G)
Interconnect equipment cord (single port)
Cross-connect patch cord (MC, IC, or HC) (sing le port)
Interconnect equipment cable (multi port/ circuit)
Horizontal cabl e
® Backbone cable
Horizontal connection point (HCP)
Application-Specific Components
Some applications or services require specific components (e.g., baluns intended for
impedance matching, devices used for splitting 4-pair cabling into two or more separate
physical lines).
Application-specific devices shall not be used as part of the horizontal cabling system, and
they shall be kept external to the telecommunications outlet/connector and HC (FD).
Keeping such application-specific components external to the horizontal cabling system will
facilitate the use of the cabling for generic network and service requirements.
© 2020 BICSI®
5-15
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Application-Specific Components, continued
Transition Points
UTC is flat, low-profile cabling designed to be installed directly on the surface of a floor
and covered with carpet or tiles. In some cases, UTC is implemented as a part of a zone
distribution system where cabling runs are restricted to a limited area and serviced by one or
more TPs (used to accommodate the transition from round [distribution] to flat [UTC] cable
types) within or along the perimeter of the area served.
Although some standards define UTC with TPs as elements of horizontal cabling, this
technology is not recommended in telecommunications cabling because of a number of
negative aspects related to performance.
UTC may be used as a part of the horizontal distribution system when other distribution
systems are not feasible. UTC, under limited circumstances, is deployed in the WA to provide
connectivity ofWA devices to the horizontal cabling. These UTC systems are composed
of two main components-the UTC cabling and the TP where the UTC cabling connects
(transitions) to the horizontal cabling. TPs are located in permanent spots such as building
columns, permanent walls, and flush floor boxes. UTC connecting hardware and cabling may
not be compatible with high-performance balanced twisted-pair cabling.
Bridged Taps
A bridged tap is a method that was widely used in the past to divide one physical
communications line into several cabling paths to support multiple analog subscriber devices.
A bridge tap has little effect on pure analog transmissions, such as traditional voice services,
but can adversely affect digital signals, including potential signal power loss, disruption, and
corruption.
Because of the significant risk of decreased performance, bridge taps are not allowed in any
balanced twisted-pair cabling system (ISP and OSP). If a bridge tap is required to support an
analog signal in a specific work area, then it should be by use of an adapter placed external to
the permanent link work area connector (outlet).
Splices
In general, splicing is not permitted within the horizontal cabling system. The only permitted
exception is with the use of optical fiber cabling when joining the optical fiber cabling to
single-ended cords (i.e., pigtails) to accomplish connection to connecting hardware in the HC
(FD) and telecommunications outlet/connector. When used in this manner, there shall be no
more than two splices in the individual horizontal cabling channel. An additional two splices
would be allowed if pigtail splicing connectors are located at a CP.
TDMM, 14th edition
5-16
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Horizontal Cabling Media
Allowed Media Types
The following types of transmission media are allowed in the horizontal cabling system:
• Category 5e, 6, 6A, 7, 7A and 8 four-pair 100-ohm balanced twisted-pair cables and
corresponding connecting hardware
• OM3, OM4, and OMS (501125-!lm) optical fiber multimode minimum 2-strand cables and
corresponding connecting hardware
• OS1a and OS2 optical fiber singlemode minimum 2-strand cables and cotTesponding
connecting hardware
Details relating to the horizontal cabling system transmission media and connecting hardware
can be found in Chapter 6: ICT Cables and Connecting Hardware.
Distances
Cabling segment lengths are defined based on the physical length of the cable jacket.
Within the permanent link, the maximum cable length shall be no more than ;::;90 m (295 ft)
regardless of the type of transmission media used.
Within the channel, the total length of cabling shall not exceed ;::;1 00 m (328 ft). In addition,
the total combined length of flexible cabling (e.g., equipment cords, patch cords) within the
channel shall not exceed ;::;1 0 m (33 ft) except when longer work area equipment cords are
permitted in conjunction with a MUTOA.
When utilizing balanced twisted-pair cabling, in addition to the requirements above, an
individual balanced twisted-pair cord used within the channel but not within the permanent
link shall be no longer than:
• ;::;5 m (16.5 ft) for 24AWG cords.
• ;::;3.96 m (13 ft) for 26 AWG cords.
© 2020 BICSI®
5-17
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Allowed Media Types, continued
Figure 5.10 provides the total length of cabling in the horizontal cabling system channel. This
figure offers the overall channel length in an interconnection and cross-connection model with
derating based on the conductor size of work area equipment cords ( 1), including equipment
cords (1) and patch cords (2) used in the HC (FD).
Figure 5.10
Total cable length in the horizontal cabling system channel
r----~----------------------,
--,-0.
i
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®I
: TR In "~"P illilllllilli' ill!iiiJilli illiliJiiilli I
i
I
i
000000
IJ
:
:-~~-------------------------:
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:
&iii~~]----------·--·---··- ~------ ··-----·-·-····l·-<J------··-§RD_
I0 i
CD ~~·
·-----------------------------·
I
i
I
.
-~
I
i
I
L-----------------------------~
: WA
I
I
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I
______j_<~]---·-··---~-!~
CD
I
'-'
:
Connections
0
®
©
1
Cabling
G)
Interconnect equipment cord (single port)
Patch panel/termination hardware
0
Cross-connect patch cord (MC, IC, or HC) (single port)
Telecommunications outlet/connector {TO)
G)
Interconnect equipment cable (multi port/circuit)
Consolidation point (CP)
®
0
Multiuser telecommunications
outlet assembly (MUTOA)
I
~-~:
I
,\(~;_.<,
I
I
I
I
I
L-----------------------------~
Active equipment
@
'
.
0 Horizontal cable
® Backbone cable
Horizontal connection point (HCP)
TDMM, 14th edition
5-18
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Allowed Media Types, continued
Cable Slack
Providing cable slack is recommended to enable the possibility of future changes in the
horizontal cabling system configuration:
• In the TR:
-Balanced twisted-pair cabling-Sufficient to reach the farthest corner of the TR via the
pathways plus the distance from floor to ceiling without exceeding the ;:::;90 m (295 ft)
limitation.
-Optical tiber cabling-Sutficient to reach the farthest corner of the TR via the pathways
plus the distance from floor to ceiling and an additional ;:::;3 m (l 0 ft) of slack for storage
inside hardware without exceeding the ;:::;90 m (295 ft) limitation.
• In the work area:
- Balanced twisted-pair cabling- ;:::;0.3 m ( 1 ft)
-Optical fiber cabling- ;:::;J m (3.3 ft)
Cable slack shall be taken into consideration in the total length of the horizontal cabling
system segments.
© 2020 BICSI®
5-19
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Work Areas and Open Office Cabling
Overview
The work area includes those spaces in a building where occupants normally work and
interact with their telecommunications equipment. While work areas have traditionally been
fixed, discrete locations, open office cabling design practices have introduced flexible layouts
to support collaborative work by small teams. Such spaces are often rearranged to meet
changing requirements of group work. Many other open office work situations also require
frequent reconfiguration. An interconnection in the horizontal cabling allows open office
spaces to be reconfigured frequently without disturbing horizontal system cabling runs.
Work area equipment that may require access to the horizontal cabling includes:
• Telephones.
• Networking equipment.
• Fax machines.
• Computers.
• Network peripherals.
• Any device plugged into a telecommunications outlet/connector that is located within the
work area.
To accommodate equipment in the work area, the following components are typically used as
needed:
• Telecommunications outlet/connector.
• Work area equipment cords.
• MUTOAs and CPs.
• WAPs.
NOTE: The key elements of open office cabling are the MUTOA and CP.
Tt is important to properly design the work area telecommunications cabling or wireless
system to accommodate the needs of both the occupants and the equipment that occupants
use.
NOTE: See BICSI's Irzfin·mation Technology Systems Installation Methods Manual for details
relating to cabling installation.
Telecommunications Outlet/Connector
The term telecommunications outlet/connector describes a connecting device
(e.g., balanced twisted-pair outlet, optical fiber connector/adapter) in the work area on
which horizontal cabling terminates. This term should not be confused with the term
telecommunications outlet box, which describes a housing used to hold telecommunications
out! ets/connectors.
NOTE: A high density of telecommunications outlets/connectors will enhance the ability of
the cabling system to accommodate changes.
TDMM, 14th edition
5-20
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Telecommunications Outlet/Connector, continued
Balanced Twisted-Pair Telecommunications Outlet/Connector
With few exceptions, balanced twisted-pair cabling standards require each 4-pair cable to be
terminated to an 8P8C-type modular connector at the work area.
NOTE: For detailed information on balanced twisted-pair connectors, refer to
Chapter 6: ICT Cables and Connecting Hardware.
Most cabling standards simply specify the pairing of pins without actually assigning color
designations. The two common pin pairings are T568A and T568B. ·rhe pin/pair assignments
for these connectors are shown in Figure 5.11.
These assignments are compatible with all known telecommunications applications intended
to operate over l 00-ohm balanced twisted-pair cabling provided the same assignments are
maintained throughout the horizontal cabling run.
Figure 5.11 shows two pin/pair assignment options from different standards. These
illustrations depict the front view of the telecommunications outlet/connector. The colors
shown are associated with the horizontal distribution cabling.
Figure 5.11
Pin/pair assignments
Pair 3
Pair 2
1
2
3
4
White Green White Blue
Green
Orange
© 2020 BICSJ:®
5
6
7
1
8
White Orange White Brown
Blue
Brown
2
3
White Orange White
Orange
Green
4
Blue
5
Jack
positions
Jack
positions
T568A
T568B
5-21
6
7
8
White Green White Brown
Blue
Brown
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Telecommunications Outlet/Connector, continued
Optical Fiber Telecommunications Outlet/Connector
There are many optical fiber connector/adapter types that satisfy the mechanical and
transmission performance specifications of cabling standards. The ICT distribution designer
may consider any of these optical fiber connector/adapters. Three of the most common
multimode and singlemode optical fiber connectors used are:
. sc
• ST
• LC
NOTE: For detailed information on optical fiber connectors, refer to Chapter 6: ICT Cables
and Connecting Hardware.
Telecommunications Outlet Box location Considerations
The following guidelines for planning the location oftelecommunications outlet assemblies in
the work area should be considered:
• Each work area shall have a minimum of one telecommunications outlet with a minimum of
two recognized connectors per outlet.
• For work areas in which it may be difficult to install future additional telecommunications
outlets/connectors (e.g., in private offices), a minimum of two telecommunications outlets
should be provided and located for equipment access flexibility (e.g., on opposing walls).
• The ICT distribution designer should coordinate with the customer's representative and
advise them on the importance of having the appropriate quantity of outlets located on the
initial installation. When user's equipment is not going to be placed adjacent to a wall,
consideration should be given to using floor outlets or utility columns to avoid tripping
hazards.
• Work area telecommunications outlet box size requirements vary based on codes, standards,
and best practices as follows:
- The outlet box should be a minimum of:::::] 00 mm ( 4 in) x ~I 00 mm ( 4 in) x
(2.25). This will accommodate one or two 27 mm ( 1 trade size) conduits.
~57
mm
- Where a larger conduit is required, the box size should be increased accordingly.
A maximum 35111111 (1-1/4 trade size) conduit will require an
~120 mm (4 11/16 in) x :::::120 111m (4 11/16 in) x 64111m (2.50 in) outlet box.
Specialty boxes may be used in place of the above as appropriate.
TDMM, 14th edition
5-22
© 2020 BICSJ:®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Telecommunications Outlet/Connector, continued
• The lCT designer shall review the electrical and shop drawings for pathways and spaces to
support the ICT infrastructure.
• The ICT designer shall verify that all pathways are specified.
Special attention should be given to the diameter of the cable specified. The cable diameter
and the number of cables specified will determine the minimum size conduit required:
• Telecommunications outlet boxes may require supports for attaching the box and a suitable
faceplate to support the telecommunications outlets/connectors that are housed by the work
area telecommunications outlet box.
• The work area telecommunications outlet box should be located near an electrical outlet
(e.g., within ;::::I m [3.3 ft]) and installed at the same height.
• Floor-mounted telecommunications outlet boxes and monuments and the work area
equipment cords extending from them can present a tripping hazard. The location of these
floor-mounted telecommunications outlet boxes should be coordinated with furniture to
minimize such hazards and should be removed when not in use.
• Cabling system performance may be sensitive to the arrangement and organization of cable
slack located behind the telecommunications outlet/connector. This general rule applies to
all forms of media. Sufficient space shall be provided in the telecommunications outlet box
or equivalent space so that minimum cable bend radius requirements are not exceeded.
The location, mounting, or strain relief of the telecommunications outlet/connector should
allow pathway covers and trim to be removed without disturbing the cabling termination.
Care should be exercised to ensure that telecommunications outlets/connectors are mounted
in such a way that they do not significantly reduce the required pathway cabling capacity.
Open office furniture openings provide for mounting faceplates containing one or more
telecommunications outlets/connectors. Numerous sizes of openings are commonly available.
A minimum clearance of ;::::30.5 mm ( 1.2 in) should be provided. If openings are not available,
then the telecommunications outlet/connector box should be secured to the kick plate with
screws that are blunt or filed in the back to ensure they do not damage telecommunications
cabling or electrical power wiring.
© 2020 BICSI®
5-23
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Telecommunications Outlet/Connector, continued
Typical dimensions for a furniture opening to support a telecommunications faceplate are
shown in Figure 5.12.
Figure 5.12
Typical dimensions for furniture opening for telecommunications faceplate
L (length)
H (height)
T (thickness)
R (radius)
C (clearance)
TDMM, 14th edition
Dimension
mm (in)
Tolerance
mm (in)
(2. 75)
~1(0.04)
~70
~35
(1.375)
~1.4 (0.055)
~4.1 (0.16) maximum
~30.5 (1.20) minimum
5-24
~0.90
~0.64
(0.035)
(0.025)
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Work Area Equipment Cords
Work area equipment cords, sometimes referred to as equipment cables or station cords,
extend from the telecommunications outlet/connector or MUTOA to the work area
telecommunications equipment. Although work area equipment cord cabling is critical to
assuring good horizontal channel performance, these cords are often the weakest link in the
channel, regardless of the media type.
Work area equipment cord types may vary depending on the work area equipment attached
to the cabling. Typically, work area equipment cords with identical connectors on both ends
are used. When work area equipment specific adaptations are needed (e.g., installing a balun),
they shall be external to the telecommunications outlet/connector or MUTOA.
lfthe work area equipment cord's transmission performance is less than that of the horizontal
cabling to which it connects, then the transmission performance of the entire channel will be
reduced to that of the lesser performing work area component. Thus, work area equipment
cord types that connect to the horizontal cabling shall meet or exceed the performance
requirements of the horizontal cabling to which they connect. This requirement refers to
the matching of category or classes of cables and cords with the understanding that cords
constructed with stranded conductors of the same gauge as the cable conductors will have a
higher attenuation value.
Factory assembled, balanced twisted-pair and optical fiber work area equipment cords may
help to reduce the performance risk sometimes associated with field assembled work area
equipment cords relative to the horizontal cabling system performance.
Multiuser Telecommunications Outlet Assembly (MUTOA)
The MUTOA serves as a method of connecting more than one user (work area) to the
horizontal cabling system.
MUTOAs may be advantageous in open office spaces that are moved or reconfigured
frequently. A MUTOA facilitates the termination of horizontal cabling system cables in a
common location within a furniture cluster or similar open area.
The use of MUTOAs allows the horizontal cabling to remain unchanged when the open office
plan is changed. Work area equipment cords originating from the MUTOA should be routed
through work area pathways (e.g., furniture pathways). The work area equipment cords shall
be connected directly to work area equipment without any additional connections.
© 1020 BICSI®
5-15
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Multiuser Telecommunications Outlet Assembly (MUTOA), continued
Figure 5.13 is an example of an open office work area design using a MUTOA. Multiple work
areas are served by one or more MUTOA.
Figure 5.13
Example of MUTOA application
r----------------,
TR
HC (FD)
Work area
L---------
___
...
Work area
MUTOA
I
Work area
HC (FD) = Horizontal cross-connect (floor distributor)
MUTOA = Multiuser telecommunications outlet assembly
TR = Telecommunications room
TDMM, 14th edition
5-26
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Multiuser Telecommunications Outlet Assembly (MUTOA), continued
Multiuser Telecommunications Outlet Assembly (MUTOA) Design
Considerations
Each open office furniture cluster should be served by at least one MUTOA. A single
MUTOA should be limited to serving a maximum of 12 work areas (all part of one furniture
cluster), taking into account the maximum work area equipment cord length requirements.
The larger the MUTOA capacity, the longer the work area equipment cords are likely to span.
Spare capacity should be considered when sizing the MUTOA. The use of high-density patch
panels may in some cases be used as a MUTOA.
The use of a MUTOA cabling design option allows work area equipment cords to extend
beyond ::::oS m ( 16.5 ft), depending upon the length of the horizontal cable.
NOTE: The total channel length is reduced as the horizontal cable is shortened because
stranded conductor cables contribute more insertion loss (attenuation) than solid
conductor cables. Do not use 24 AWG work area equipment cords with lengths that
exceed ::::o22 m (72ft).
Maximum lengths in Table 5.1 are based on stranded work area equipment cords exhibiting
up to 20 percent higher insertion loss than solid horizontal cable.
NO'rE: Balanced twisted-pair work area equipment cords with stranded conductors of
26 AWG may exhibit attenuation up to 50 percent higher than the corresponding solid
conductor horizontal cable.
The maximum length of the open office work area equipment cords, based upon insertion loss
considerations, shall be determined according to the following formula:
c
c~:~H)
W
C-T
W < 22m for 24 AWG cords,
W < 17m for 26AWG cords
Where:
C
is the maximum combined length (m) of the work area equipment cord,
HC (FD) equipment cord, and HC (FD) patch cord.
H
is the length (m) of the horizontal system cable.
D is an insertion loss derating factor:
20% (0.2)- for 24 AWG cords,
50% (0.5)- for 26 AWG cords.
W is the maximum length (m) of the work area equipment cord.
T
© 2020 BICSI®
is the maximum total length (m) of HC (FD) equipment cords and optional
HC (FD) patch cords in the TR:
5 m ( 16.5 ft) for 24 AWG cords,
3.96m (13ft) for 26 AWG cords.
5-27
TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Multiuser Telecommunications Outlet Assembly (MUTOA), continued
Table 5.1 contains the reference data calculated using the above formulas taking into account
the requirements for maximum allowable length ofHC (FD) equipment cords and HC (FD)
patch cords in the TR.
Maximum length of the balanced twisted-pair horizontal cabling system when using a
MUTOA shall not be more than ;::;90 m (295ft) regardless of transmission media type.
The total length of the balanced twisted-pair horizontal channel, including the permanent
link, work area equipment cord, HC (FD) patch cords, and HC (FD) equipment cord in the
horizontal cross-connect when using a MUTOA shall not be more than;::::; 100m (328 ft).
TableS.!
Maximum allowable cable lengths with the use of multiuser telecommunications outlet assemblies
Length of
Horizontal
System Cable
m (;:::ft)
24AWG
Patch Cords
Maximum Combined
Length of Work Area
Maximum
Cords, Patch Cords,
Length of Work
Area Cord
and Equipment Cords
m(;:::ft)
m (;:::ft)
26AWG
Patch Cords
Maximum Combined
Maximum
Length of
Length of Work Area
Work Area
Cords, Patch Cords,
Cord
and Equipment Cords
m (;:::ft)
m (;:::ft)
90 (295)
5 (16.5)
10 (33)
4 (13)
8 (26)
85 (279)
9 (30)
14 (46)
7 (23)
II (36)
80 (262)
13 (43)
18 (59)
II (35)
15 (49)
75 (246)
17 (57)
22 (72)
14 (46)
18 (59)
70 (230)
22 (72)
27 (89)
17 (56)
21 (70)
NOTE: No reduction of optical fiber cabling equipment cords in the work area or equipment
cords and patch cords at the horizontal cross-connect is required.
MUTOAs shall be administered by the rules specified for connecting hardware found in
Chapter 10: Telecommunications Administration.
Since work area equipment cords connecting the MUTOA to the work area active equipment
may be rather long (up to ;::;22m [72ft]), they should be labeled on both ends with a unique
cable identifier. The end of the work area equipment cord at the MUTOA should be labeled
with the work area identifier it serves, and the end at the work area active equipment should
be labeled with the MUTOA and its position identifier.
TDMM, 14th edition
5-28
© 2020 B!CSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Multiuser Telecommunications Outlet Assembly (MUTOA), continued
locating Multiuser Telecommunications Outlet Assemblies
(MUTOAs)
MUTOAs shall be located in fully accessible, permanent locations
(e.g., building columns, permanent walls). Do not install MUTOAs in ceiling spaces,
under access flooring, or in any obstructed areas. MUTOAs shall not be installed in
furniture unless that furniture is permanently secured to the building structure.
For balanced twisted-pair cabling, MUTOAs should be located at least ::::::15m (49ft) from
the HC (FD) to minimize the effects of multiple connections in close proximity on near-end
crosstalk loss and return loss.
When using MUTOAs in areas with WAPs, give special attention to the installation of the
cabling to access points directly from the ·rR/TE, not from the MUTOA located in the area.
MUTOAs are only intended to service devices in furniture clusters.
The work area side of the MUTOA should be marked with the maximum allowable work area
equipment cord length. See Chapter I 0: Telecommunications Administration for additional
details about labeling and record keeping.
Consolidation Point (CP)
The CP is an interconnection point within the horizontal cabling system. Like the MUTOA,
a CP may be used for balanced twisted-pair cabling or optical fiber cabling.
The functional difference between the CP and the MUTOA in the open office environment is
that the CP introduces an additional connection for each horizontal cabling run.
A CP may be useful when reconfiguration is frequent, but not so frequent as to require the
flexibility of the M UTOA.
The CP provides a convenient method for rearrangement of horizontal cabling that may
be employed in furniture system layouts. CPs can also be used to serve private office
arrangements, especially when zone cabling is employed. See Figure 5.14 for an example of
CPs being used in a combined furniture system and private office work area environment.
A CP allows standard horizontal cables to be extended into work area pathways and
terminated on telecommunications outlets/connectors that are dedicated to each individual
user.
However, the use of a CP does not extend the length of horizontal cabling farther than
::::::90 m (295 ft) from the cable tennination at the HC (FD) to the cabling termination at the
telecommunications outlet/connector or MUTOA.
© 2020 BICSI®
5-29
TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Consolidation Point (CP), continued
Figure 5.14
CPs used in a combined furniture system and private office work area environment
TR
HC (FD)
Open office
area
CP =
HC (FD) =
TO=
TR =
Consolidation point
Horizontal cross-connect (floor distributor)
Telecommunications outlet/connector
Telecommunications room
Consolidation Point (CP) Design Considerations
CP implementation is a variation of horizontal cabling. Therefore, a good first step in
the design of the CP is to review the rules and guidelines provided in this chapter before
proceeding further. Some cabling systems manufacturers and certain categories of cabling
may not recommend the use of CPs. Always check with the cabling system manufacturer to
validate all product warranties and design or installation recommendations.
When used, each open office furniture cluster should be served by at least one CP. It is
recommended that the CP should be limited to serving a maximum of 12 work areas. Spare
capacity should be considered when sizing the CP.
The CP can be located in the following spaces, if permitted by codes, standards, and
regulations:
• Suspended ceilings
• Access floors
• Modular oflice furniture
• Work area
TDMM, 14th edition
5-30
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Consolidation Point (CP), continued
Some additional considerations and guidelines that apply specifically to the CP include:
• CPs shall not be used for direct connection to active equipment. Cross-connections shall
not be used at a CP. No more than one CP shall be used within the same horizontal system
cabling nm.
• For balanced twisted-pair cabling, the CP should be located at least ::::.;]5 m (49ft) from the
HC (FD).
• CPs shall be located in fully accessible and permanent locations. CPs shall not be located in
an obstructed area.
• The CP shall be sized and cabled so that it meets the telecommunications requirements of
the zone it serves. If the floor space requirements change for an existing CP, then the CP
should be reconfigured to accommodate the new requirements.
• Regardless of where they are installed, CPs shall be administered in the same manner as
telecommunications cabling (cable and connecting hardware), pathways, and spaces as
described in applicable cabling administration standards.
NOTE: Refer to Chapter I 0: Telecommunications Administration for additional
information.
• When installed in modular furniture systems, that unit of furniture shall be permanently
secured to the building structure to avoid potential damage to the cabling.
• When installed in plenum spaces used for environmental air, conformance to applicable
building codes shall be met.
• When installed in suspended ceiling spaces or access floor spaces, those spaces shall
be fully accessible without moving building fixtures, equipment, or heavy furniture
or disturbing building occupants. Heavy furniture includes objects (e.g., file cabinets)
weighing ::::.;45.4 kg (1 00 lb) or more.
• The CP shall be fully accessible when placed above the suspended ceiling or beneath the
access floor.
• When installed in a suspended ceiling or access floor space, the ceiling or floor tile locations
should be clearly and permanently marked and identified as containing a CP. When ceilings
or access floors arc replaced, ensure that the CP locations are identified and marked again
when the new ceiling or access floor is in place.
• When in non-plenum interstitial space, protect connecting hardware from physical abuse
and foreign substances with an enclosure that satisfies the requirements of the Alll.
• When the CP is located in an air-handling space (e.g., plenum ceiling, access floor),
the complete CP assembly (e.g., enclosure with connecting hardware) shall meet the
requirements of the AHJ. Follow manufacturers' instructions for installation to ensure
compliance to heat and smoke test conditions.
• The use of CPs in ceiling or access floor spaces shall conform to the AHJ for other spaces
used for environmental air. Telecommunications outlets/connectors or MUTOAs shall not
be located in the ceiling space.
WARNING: Do not place active telecommunications equipment directly within the ceiling
or access floor space.
© 2020 BICSI®
5-31
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Consolidation Point (CP), continued
Advantages and Disadvantages of the Consolidation Point (CP)
Advantages of the CP are that they:
• May be useful when open office furniture reconfiguration is frequent. CPs provide
additional cabling system design flexibility for ICT distribution designers.
• Can potentially decrease work area cabling installation time and the additional expense of
materials when rearranging open office furniture and associated cabling.
Disadvantages of the CP arc that they:
• Generally increase the original installation time and expense of additional materials.
• Add additional labeling requirements.
• May contribute to the complexity of testing and troubleshooting of the installed horizontal
cabling.
• May degrade the transmission characteristics (i.e., insetiion loss, crosstalk, return loss) of
the cabling channel.
locating Consolidation Points (CPs)
While CPs may be deployed in all manner of layouts, the following options are common
CP layouts:
• CPs located on all columns (see Figure 5.15)
• CPs located in a space between the columns (see Figure 5.16)
• CPs located in checkerboard order (see Figure 5.17)
• CPs located on columns close to the building core (see Figure 5.18)
Table 5.2 provides a comparison of common layouts because each layout, although similar,
has ditTerences that may affect the overall usability of the horizontal cabling.
Table 5.2
Comparison of CP locations
Consolidation
Point Location
Work Area
Equipment Cord Lengths
Expansion of
Consolidation Point
On all columns
Tend to be shortest
Changes easily
accommodated
Highest
Highest relative
to other
configurations
Between columns
'fend to be shorter
Changes easily
accommodated
High
Higher relative
to other
configurations
Checkerboard
Tend to be longer
Changes easily
accommodated
Low
Lower relative
to other
configurations
Close to
building core
Longest
Does not
accommodate
changes easily
Lowest
Lowest relative
to other
configurations
TDMM, 14th edition
5-32
Flexibility
Deployment
Cost
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Consolidation Point (CP), continued
Figure 5.15
CPs located on all columns
CP
CP
CP
CP
CP
CP
A
CP
CP
CP = Consolidation point
© 2020 BICSI®
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TDMM 1 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Consolidation Point (CP), continued
Figure 5.16
CPs located in a space between the columns
D
D
D
CP = Consolidation point
TDMM, 14th edition
5-34
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Consolidation Point (CP), continued
Figure 5.17
CPs located in checkerboard order
CP
D
CP
CP
CP = Consolidation point
© 2020 BICSI®
5-35
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Consolidation Point (CP), continued
Figure 5.18
CPs located on columns close to the building core
CP = Consolidation point
Wireless LAN (WlAN) Access Point {AP)
A WLAN AP is a network device located in areas of a building or campus and placed in
relatively close proximity to where users interact with their wireless enabled network devices.
APs allow wireless enabled devices (e.g., computer, printer) to connect to a wired network
using Wi-Fi or related standards. AP network devices are typically mounted on walls or
ceilings with structured cabling that provides a physical connection to an HC (FD).
NOTE: For more information, see Chapter 16: Wireless Networks.
TDMM, 14th edition
5-36
© 2020 BICSI®
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Simultaneous Data and Power Transmission within
Horizontal Cabling
Overview
PoE and other practices (e.g., HDBaseT) allow the transmission of de power and data
simultaneously over balanced-twisted pair and other forms of communication cabling. The
HDBaseT Alliance created a Power over HDBaseT (PoH) standard that delivers a maximum
of95 W over four pairs. HDBaseT 1.0 and HDBaseT 2.0 have the same power specifications.
NOTE: When hybrid copper/optical fiber cabling is used to support data and power
transmission, only the data signal is transmitted over the optical fiber strands. Power
is supplied through integrated conductors within the cabling sheath.
Although there are several variations of PoE, each successive type, while increasing
maximum power, is backwards compatible. HDBaseT currently has two levels of
specification with identical power profiles. PoE and HDBaseT currents are summarized in
Table 5.3.
Table 5.3
PoE and HDBaseT current specifications
Transmission
Method
Power at Source
(W)
Maximum Current per
Conductor (rnA)
Maximum Current
per Pair (rnA)
PoE Type 1
15.40
175
350
PoE Type 2
30
300
600
PoE Type 3
60
300
600
PoE Type 4
100
500
960
POH
100
500
1000
PoE = Power over Ethernet
PoH = Power over HDBaseT
Cabling Requirements
Cabling designs that support data and power transmission shall confonn to the requirements
of regulations, local and national codes (e.g., NFPA 70, CSA C22.1) and the AHJ, both for
the premises and the application being served. Additionally, for existing installations that
meet the conditions for the use of non-recognized cabling, any non-recognized cabling to be
installed shall have conductors with a minimum size of 0.205 mm 2 (24 AWG).
The operating temperature of cabling should not exceed 60
cable jacket rating.
© 2020 BICSJ®
5-37
oc (140 °F), regardless of the
TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Recommendations
Equipment cords and coverage area cables used for data and power transmission should have
conductors with a minimum size of 0.205 mm 2 (24 AWG).
PoE Type 3, PoE Type 4, HDBaseT, and other data and power methods capable of suppotiing
a minimum of 5GBase-T transmission should use cabling containing solid conductors.
For new installations, consider specifying cabling with 0.326 mm 2 (22 AWG) conductors if:
• The specific building system (e.g., audio systems, video displays) is expected to require
power exceeding 60 W during the life cycle of the building
• Future flexibility is desired in the types of systems that could be supported.
NOTE: General trends within intelligent building systems include the continued integration
of multiple functions within one device (e.g., LED luminaire with integrated
environment sensors, IP audio speaker, and WAP) and these new devices increase
power and data bandwidth requirements.
Higher category-rated cable typically means larger conductor sizes, and as power currents
increase, these larger conductors have lower resistance and less heating than smaller cable
conductors. TIA testing, in Figure 5.19, compares the temperature rise in 100 cable bundles
of category 5e, 6, 6A, and 8 as the power increases over all four pairs. The higher-category
cabling is able to support more current capacity at a maximum allowable 15 degree
temperature increase (Figure 5.19). It becomes clear that higher category cabling minimizes
temperature increases while supporting higher PoE class PDs.
Figure 5.19
Temperature versus wattage for category cable types
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TDMM, 14th edition
-
6
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© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Recommendations, continued
The designer should consider specifYing cable with a listing temperature of 75 °C (167 °F) or
reducing the number of cables in a bundle for cables passing through locations with elevated
ambient operating temperatures to avoid exceeding listed cable limits. Cable heating because
of PoE power deployment can cause cable jacket and insulation materials to become brittle,
resulting in cable jacket cracking and insulation falling off the cable. In addition, flame
retardant prope11ies may be reduced as components within the insulation degrade from heat.
The temperature rise in cable bundles from PoE power delivery also has the potential
to cause higher bit errors because insertion loss is directly proportionate to temperature
(see Figure 5.20). Channel length may need to be reduced as a result of insertion loss caused
by cable heating or elevated ambient temperature.
Figure 5.20
Insertion loss versus temperature for category cable types
,/Jill
26 +-----------------------~------'
'
'
--1111-- Cat Se UTP limit
-11111-- Cat Se Shielded limit
--+-Cat Se UTP (24 AWG)
Cat 6 UTP (23 AWG)
--+-Cat 6A UTP (23 AWG)
-+-Cat 6A F/UTP (23 AWG)
-+-Cat 7A S/FTP (22 AWG)
16
+--------------------------------
14 ~--~----~--~----~--~----~
10
40
20
30
50
60
70
Temperature ( 0 C)
F/UTP = Foil covered unshielded twisted-pair
S/FTP = Severed foil twisted-pair
UTP = Unshielded twisted-pair
Where possible, it is helpful to plan the rack layout for non-powered and powered cables to
be mixed in the same bundle to limit cable heating.
© 2020 BICSI®
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TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Recommendations, continued
Pathways that allow airflow around cables minimize heating effects. For example, wire mesh
cable tray and cable runway will improve heat dissipation and allow for loosely laid cables
instead of tight bundles. Fully enclosed pathways (e.g., conduit) contribute to heat rise.
When selecting balanced twisted pair cabling, shielded cables often exhibit less heat build-up
than comparable unshielded cables.
Consider specifying cabling with stricter requirements based on the anticipated application in
the design. Application examples:
• BAS/BMS and facility controls are low power/low data, so conductor size is not critical to
the PoE implementations. Cable jacket temperature rating of 75 oc (167 °F) and shielding
should be given consideration, based on environment.
• Audiovisual systems using high power/high data require consideration of both balanced
twisted-pair cable performance and 23 AWG min/22 AWG conductors. Shielded category
6A/class E Acable is the minimum recommended. However, category 7/class F and
categmy 8/class I typically have 22 AWG conductors and should be considered. The
designer should also consider using a 7 5 oc (167 °F) jacket.
• Cameras are typically high data/low- to mid-power requiring minimum balanced twisted
pair cable performance and the consideration could be category 6A, which comes standard
with23AWG.
• Lighting is low data/high power; therefore, 23 AW G min/22 AW G conductors may be
recommended.
• For current WLAN systems, a minimum of category 6A/class EA is sufficient. With the
introduction of 802.11 ay/Wi-Fi systems, the provisionary of the two category 6A cable for
WLAN data considerations should provide sufficient power capacity.
Small Diameter Cables
28 AWG cable shall not be used as horizontal or backbone cable. It is a best practice for
equipment cords and coverage area cables used for PoE data and power transmission to have
conductors with a minimum size of 0.205 mm 2 (24 AWG). Patch cords smaller in diameter
than 28 AWG shall not be used to support the delivery of power. Some users may choose 28
AWG only as patch cabling to connect an endpoint device.
lf28 AWG cords are selected:
• Use small bundle sizes. For PSEs sending more than 30 W ofPoE, bundle 28 AWG patch
cords in bundles of 12 or less. Small bundles diminish the impacts of cable temperature rise.
If power isn't being distributed, then there are no limitations to 28 AWG bundle sizes.
• Maintain separation distance. For power delivety above 30 W to further support airflow,
separate cable bundles a minimum of;::::38 mm (1.5 in) apart from the outer edge of a bundle
to the outer edge of the next bundle.
• Avoid conduit/enclosures and overfilling. Patch cords shall not be placed in conduit or other
enclosures where heat build-up could occur. Cable management should not be overfilled or
heat dissipation could be reduced.
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© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Cabling Bundles
When power is applied to twisted-pair cabling, the temperature of the cabling will rise
slightly because of resistive heat generation in the conductors. The level of temperature rise
will increase when cables are bundled. The electrical performance of the cable will also
degrade slightly because ofthe temperature rise. The level of temperature rise can also be
affected by the construction of the cabling and pathway type.
Depending on the amount of power per conductor and the other factors listed above, it is
possible for cables within the center of the bundle to exceed the listed temperature on the
cable jacket. While many AHJs prohibit installation methods that cause a single cable's jacket
temperature to be exceeded, some AIUs have also enacted limits on the number of cables
contained within a bundle to further decrease the possibility of excess cable temperature.
For all cables, recommended maximum bundle size is 24 cables.
Authority Having Jurisdiction (AHJ), Codes, and Standards
In response to the increased PoE power being delivered, the 2017 edition of the NfPA
NE'C established ampacity ratings for balanced twisted-pair cabling. NEC section 725.144,
Transmission of Power and Data, includes an ampacity table for 4-pair class 2 and class 3
cables and includes 22, 23, 24, and 26 AWG. The ampacity ratings are based on bundle size,
conductor diameter (expressed in AWG), and cable temperature ratings. They assume a worst
case and specify ampacity for cable temperature ratings of 60 °C ( 140 °F), 7 5 °C ( 167 °F),
and 90 °C ( 194 °f), assuming an ambient temperature of 30 oc (86 °F). Derating equations
are provided for higher temperatures. Section 800.3 (H) in the 2017 NEC requires that
communications cables are not allowed to exceed their temperature ratings. Other countries
followed with similar codes. Check with the AHJ for limits on bundle size.
The heating effects from PoE, design choices, and installation practices is a recent
development. Several jurisdictions (e.g., U.S., Canada) have created code requests to address
this issue, and are modified as new information and testing becomes available.
Documents such as TIATSB-184-A and ISO/fEC TS 29125 provide additional information
about cable bundle sizes and their effect on operating temperature. Standards bodies have also
developed materials concerning bundle sizes, derating channel lengths, and other design and
installation considerations.
TfA TSB-184-A analyzes the problem of cable temperature rise from a slightly different
direction. The TSB assumes an ambient temperature of 45 oc (113 °f) and provides
maximum bundle sizes to yield a temperature rise no greater than 15 °C (27 or:). 'fhe TIA
recommendations are based on 60 °C ( 140 °F), the most common cable temperature rating.
The TSB gives guidance for cables installed "in air" as well as in conduit.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Direct Current (de) Resistance
PoE power is transmitted using common-mode voltage on the pairs. Current is evenly split
between the two conductors. The de resistance of each conductor in the pair must be equal
(balanced). Any difference between the pairs is reported as de resistance unbalance.
de resistance unbalance may be included in cable manufacturer specifications. Inconsistent
terminations can also add de resistance. Some field testers are capable of testing
de resistance. Excessive de resistance unbalance between multiple pairs can prevent PoE
systems from functioning. Copper coated aluminum, copper coated steel, and other nonstandard conductors arc not compliant with industry standards and do not support PoE
applications because of their increased de resistance.
Power over Ethernet (PoE) Connectors
Another consideration with higher current PoE is the potential for damage over time to
8P8C modular connectors in the channel. Metal in the connector body instead of plastic
creates an improvement in heat dissipation. For this reason, metal body connectors, not
plastic, are recommended.
For PD modular connectors and patch cords, 50 micron gold-plated tines should be specified
as connectors and patch cords that do not have gold plating will fail earlier when used in PoE
applications.
There is also potential for electrical arcing damage to the connector contacts supporting
remote PDs. Consider specifying connectors compliant with the contact resistance
requirements included in IEC 60512-99-00 I.
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© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Power Source Equipment (PSE)
Endspan Power Source Equipment (PSE)
A growing trend in the networking industry is to install only network switches with PoE ports
as a minimum standard. Thus, if devices are added in the future, the switch will be able to
accommodate PoE capabilities. Deploying large numbers of PoE switches, however, leads
to considerable standby power. The standby power multiplied by the number of ports in the
network can result in significant amounts of wasted power. To improve power consumption,
IEEE 802.3bt allows class 5-8 PDs to use less than 20 m W to keep the port alive. In a PoE
powered LED luminaire, for example, the data port must stay on while the light is turned off
but should use as little power as possible while the light is ofT.
Midspan Devices
The advantage of specifying midspan devices during design is that they offer power to PoE
devices using legacy switches.
Power injectors specified must be NRTL listed for the purpose.
WARNING: The use of unlisted or non-standards compliant equipment may provide higher
than standardized power levels, causing a cable's temperatures to be in
excess of the maximum cable jacket temperature. Overheating the cable beyond
its temperature rating may affect the ability of the cable to transmit data, result
in violation(s) of applicable codes, permanently alter or damage the cable, or
create a safety hazard.
Power injectors should be located as close as possible to the receiving equipment or device to
minimize power loss and heating of the cabling.
For systems implemented external to a building:
• Power injectors supporting these systems should be installed within a rated enclosure.
• Lightning or other surge protection should be considered and may be required by the AHJ.
• Specified surge suppressor shall not attenuate the PoE power to the PD or affect network
signals passing through it.
© 2020 BICSI®
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TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Centralized Optical Fiber Cabling
Overview
The HC (FD), deployed throughout a building and located on each floor of a building, offers
maximum flexibility to the user, especially in the deployment of distributed electronics or in
multi-tenant buildings. In spite of the advantages of distributed cross-connections, many users
of high-performance optical fiber cabling arc implementing data networks with centralized
electronics.
A centralized optical fiber cabling topology is based on the principles of a centralized optical
fiber network when using recognized optical fiber cabling in the horizontal system to support
centralized electronics and fiber-to-the-desk technology.
Centralized cabling provides connections from the work areas to the centralized crossconnect by allowing the use of any of the following methods:
• Pull-through cabling from the centralized cross-connection
• Interconnection cabling in a floor-serving telecommunications space
• Spliced cabling in a floor-serving telecommunications space
Figure 5.21 illustrates the centralized optical fiber network and the methods used for its
implementation.
Careful planning and implementation of centralized optical fiber cabling will ensure adequate
flexibility and manageability with the centralized optical fiber network. It is recommended
to consult with equipment manufacturers and system integrators to determine if these
requirements are suitable for specific networking applications.
The guidelines and requirements for centralized optical fiber cabling networks are intended
for those users who need an alternative to locating the cross-connection in the floor-serving
TRs while ensuring adequate flexibility and manageability of optical fiber links, including the
ability to migrate to a cross-connection located in the floor-serving TR.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Overview, continued
Figure 5.21
Centralized optical Aber cabling
,go m
r- TR/TE
I
-
~
1--------- (2g5 ft)
-
-
---------i
maxirnurn
I
Work area
_J
_sp.::_:e _
,go m
_ _ r=--==--=---- (295 ft) -------1
I TR/TE
maximum
Work area
r
----.,
TR
L
Work ar-ea
Pull-through
- - - ...1
.----------rl
,go m (295ft)
recommended length
pull-through
ER
ER = Equipment room
TE == Telecommunications enclosure
TR = Telecommunications room
© 2020 BICSI®
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TDMM, 14th edition
Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Centralized Optical Fiber Cabling Design
Centralized optical fiber cabling designs may utilize any of the recognized types of optical
fiber cable and connectivity.
Centralized cabling shall be designed so as to allow for migration (in part or in total) of the
pull-through, interconnect, or splice implementation to a cross-connection implementation.
Sufficient space should be provided in the 'l'R to allow for the addition of patch panels
required for the migration ofthe pull-through, interconnect, or splice to a cross-connection.
Centralized cabling shall be designed so as to allow for the addition and removal of
horizontal and intrabuilding backbone system fibers. The layout of both rack mount and
wall-mount termination hardware should be such as to accommodate modular growth in an
orderly manner.
The intrabuilding backbone system design should allow for sufficient spare capacity to
service additional telecommunications outlets/connectors from the centralized cross-connect
without the need to pull additional intrabuilding backbone system cables. The intrabuilding
backbone system fiber count should be sized to provide present and future applications to
the maximum work area density within the area served by the TR. Two fibers arc normally
required tor each application delivered to a work area.
Choosing between the pull through cabling method or backbone cabling methods
(e.g., interconnection, splice) may be based on the size ofthe installation.
• Pull-through installations arc typically used for small, one- or two-story buildings with a
limited number of users.
• Backbone to horizontal designs are used in larger buildings where permanently routed
backbone cables would minimize disruption to firestop assemblies when adding new users
to the system.
Centralized Optical fiber Cabling Distances
The centralized optical fiber cabling installation is limited to optical fiber cabling within a
building and may not be deployed between buildings or across a campus. When centralized
multi mode optical fiber cabling is used, the user needs to be aware of application specific
distance limitations. For this reason, the maximum allowable length of centralized optical
fiber cabling using the interconnection or splice methods connecting the centralized active
equipment to the work area equipment, including equipment cords at both ends, shall be
limited by the specifications of anticipated telecommunications applications.
Pull-Through Method
While there are no specific limitations of cable length in the pull-through method, specific
applications or multimode cabling properties may limit the overall length. It is recommended
that optical fiber cabling lengths do not exceed the maximum length limit for the application
or ~305m (1000 ft), whichever is smaller.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Centralized Optical Fiber Cabling Distances, continued
Interconnection and Splice Methods
The maximum allowable length of centralized optical fiber cabling utilizing the
interconnection and splice methods may be limited by the type of optical fiber cabling
selected (e.g., multimode, singlemode) and the distance limitations of the optical fiber
equipment deployed.
Additionally, the length limitation of centralized optical fiber cabling between the HC (FD)
located in the TR or TE and the work area connecting hardware should not exceed
;.::::90 m (295 tt). When implementing a centralized optical fiber system with the
interconnection or splice methods, the interconnection or splice connecting hardware should
be located in the floor-serving TR or TE.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Fiber-To-The-Outlet
Overview
FTTO is a standard-compliant and decentralized cabling concept for modern office
environments. It combines the advantages of highly efficient fiber optic technology with
the flexibility of balanced twisted-pair cabling for deployment of any IP-based network. In
contrast to the established balanced twisted-pair based structured cabling network, FTTO
additionally employs optical fiber cables for both backbone cabling and horizontal cabling.
Balanced twisted-pair cabling is only used at the work areas to connect terminal equipment
like workstations, printers, VoiP phones, or JP cameras. As a result, the FTTO system offers
rich power management functions like PoE and energy efficient Ethernet.
Telecommunications cabling infrastructures based on optical fiber offer many advantages
over the conventional cabling infrastructure based on balanced twisted-pair cabling. Optical
fibers support larger bandwidths and longer distances; they are immune to EMI; do not cause
EMI; and because of the metal-free cable setup, there are no problems with the potential
equalization. As a result of the significantly smaller outer diameter, the optical fiber cables
require smaller pathways and lead to much lower fire loads than copper cables. Because
of the advantages of optical t1ber cabling and its proliferation in horizontal cabling, the
FTTO system and PON are being implemented in a growing number of projects.
The centralized optical t1ber cabling topology has been in use to take advantage of the longer
distance and higher bandwidth supported by optical fiber technology. The FTTO system
is based on the centralized optical fiber cabling topology and is an extension of the FTTD
concept. All the components of the FTTO system are the same as those used in Ethernet
technology and copper-based structured cabling. Taking advantage of the optical fiber cabling
in horizontal, it moves the access switch layer to the work area. With FTTO, enterprises
prot1t from a highly cost-effective networking infrastructure that offers flexibility, protects
investments, and reduces life cycle costs.
With its many advantages over the copper cabling network, FTTO is widely implemented
in many enterprise networks. The FTTO design reduces the telecommunication space
requirements, saving on power and HVAC requirements in the TR. By using smaller optical
fiber cables and reducing their number, the FTTO reduces the requirement of pathway
capacity and installation time. Immunity to EMI/RFI, higher bandwidth, and lower total
cost of ownership are the other advantages of the FTTO system over the traditional network
architecture with balanced twisted-pair cabling.
TDMM, 14th edition
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© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Overview, continued
Figure 5.22
Traditional structured cabling LAN design compared with FTTO LAN
Traditional LAN
FTTO LAN
Singlemode or multimode - - ! - optical fiber backbone
i
Singlemode or multi mode ------i----H
8
optical fiber backbone
I
8
---------------------- -
--------------------Layer-3 Distribution switch
Layer-3 Distribution switch
FTTO = Fiber to the Outlet
LAN = Local area network
WAN = Wide area network
Traditional Structured Cabling System
The conventional structured cabling system uses mostly balanced twisted-pair copper cable in
horizontal (cabling subsystem A) and optical fiber in backbone (cabling subsystem B and C).
The active LAN equipment are installed in the equipment room and the floor serving
TR or TE. The core and distribution switches are placed in the equipment room and the edge
or access switches are placed in the TR or TE on each floor. The balanced twisted-pair copper
cables are terminated at the horizontal cross-connects in the TR or TE. Because of the large
number of balanced twisted-pair cables, ~s mm (0.2 in) to ~s mm (0.31 in) in diameter,
the conventional structured cabling system requires large space for termination and cable
management in the TR. The horizontal pathway has to be sufficiently sized to accommodate
the horizontal cables. The TR has to be provided with sufficient power and cooling to
maintain the environment suitable for the active network equipment that will be installed in
the TR.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
fiber-To-The-Outlet (fTTO) Structure
• The FTTO system has a structure similar to the traditional structured cabling system. Some
differences are:
• The horizontal cable is 2-strand optical flber cable, multimode, or singlemode.
• There is no active LAN equipment in the TR; the horizontal optical fiber cable is connected
to the multi-strand backbone optical fiber cable by splicing as per the centralized cabling
concept.
• The access switch will be a 4-port micro switch (FTTO switch), which will be installed in
the work areas, each micro switch serving two work areas.
• There are no cross-connects or active LAN equipment required in the TR; therefore, only a
wall mounted splice closure for splicing the backbone optical fiber cable to the horizontal
fiber cable is needed.
fiber-To-The-Outlet (fTTO) Components
The various components in an FTTO system include:
• Passive cabling
- Two-strand optical flber cable in horizontal cabling
- Category 5e, category 6 or category 6A work area patch cords for connecting the end
equipment (e.g., telephones, computers, printers, CCTV cameras, WAPs) to the FTTO
switch
- Multi-strand (e.g., 24-, 48-, 96-, 144-core) optical fiber cable in backbone cabling
-- Splice box
- Telecommunications outlet box
- Cable assemblies or splice-on or pre-polished connectors
• Containment system
Containment for horizontal cable
- Containment for the backbone cable
• Active network equipment
-Micro (FTTO) switch
- Core and distribution switch
Optical fiber Requirements
FTTO system utilizes multimode or singlemode optical fiber cabling infrastructure. The
micro switch requires 2-strand optical fiber cable, which will be spliced to the multi-strand
backbone cable at the splice box. Multiple 2-strand horizontal optical fiber cables on any
floor or zone will be spliced to multi-strand fiber cable, such as 24-, 48-, 72-, 96- or 144-core
backbone cables. The 2-strand fiber cable can be duplex type tight buffered fiber cable with
each fiber on a ;.:;2 mm (0.079 in) cable to facilitate the installation of the connector at the
work area.
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Chapter 5: Horizontal Distribution Systems
fiber Termination Methods
The 2-strand horizontal optical fiber cable can be terminated in a work area
telecommunications outlet box with suitable optical fiber connector and adapter. The
horizontal fiber cable can also be terminated by any of the following methods which otTer
high-performance, reduce installation time, and are easy to do:
• Pre-terminated assemblies
• Field termination with splice-on connectors
• Field termination with pre-polished connectors
All of these are proven methods and can be used at any installation environment.
Pre-terminated Assemblies
The pre-terminated cable assemblies can be used for large FTTO installations where the
number of fiber terminations is huge. 'T'his will help in reducing the installation time to meet
the tight project schedule. The pre-terminated cable assembly consists of a 2-strand fiber
cable that has been terminated with LC connectors on one side. The cable can be either tight
buffered or loose tube, but it must be compliant to the installation environment. A highdensity optical fiber cable is installed from the equipment room to a splice box on the floor.
The pre-terminated assembly is spliced to the high-density optical fiber cable at the splice box
and connected to the FTTO switch at the work area.
Some advantages of pre-terminated assemblies are:
• Short and reliable manufacturing lead-time
• Fast installation time
• No specialized termination training required
• No consumables or termination tool kits
• No cable preparation necessary
• No cable or connector scrap
• No termination errors on site
• Delivered fully tested, labeled, and documented
• High performing connectors with low insertion loss
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Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
field Termination with Splice-On Connector
The splice-on field-installable connectors are factory pre-polished, which eliminates the need
for polishing, adhesives, and crimping in the field to save on installation time and improve
the performance. These connectors are fusion spliced on to a duplex fiber cable at the work
area. The other end of this horizontal cable will be spliced to a high-density optical fiber
cable, which is installed from the equipment room to a splice box on the floor. This method
combines the advantages of fusion splicing and factory polishing for high-performance.
The connector body is assembled over the splice and hence it does not require a splice tray.
Some advantages of field termination with splice-on connectors are:
• Field installable.
• Uses exact length of cable required; no risk of shorts and slack of pre-terminated cables.
• Fast and easy terminations.
• No adhesives, crimping, or polishing required.
• Reduces time, material, and labor costs.
• Consistent and reliable for multimode and singlemode fiber.
• High performing connectors with low insertion loss.
field Termination with Pre-polished Connector
'T'he pre-polished connectors are factory pre-polished, which eliminates the need for
polishing, adhesives, and crimping in the field to save on installation time and improve the
performance. These connectors are field installed on to a duplex fiber cable at the work area
using a special tool. The other end of this horizontal cable will be spliced to a high-density
optical fiber cable which is installed from the equipment room to a splice box on the floor.
This method combines the advantage of factory polishing for high-performance and ease of
termination without adhesives and consumables. The connector body is assembled directly
over the ;::.::2 mm (0.079 in) cable and does not require any additional protection.
Some advantages of field tem1ination with pre-polished connectors are:
• Field installable
• Uses exact length of cable required, no risk of shorts and slack of pre-terminated cables
• Fast and easy terminations
• No adhesives, crimping, or polishing required
• Reduces time, material, and labor costs
• Consistent and reliable for multimode and singlemode fiber
• High performing connectors with low insertion loss
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Section 1: Horizontal Cabling Systems
Chapter 5: Horizontal Distribution Systems
Horizontal Pathwa s for Fiber to the Office
Overview
The horizontal cable will be two-strand optical fiber cable, which is typically
:.:::4 mm (0.15 in) in diameter. These cables will be routed from the splice closure to the
work area. Suitable horizontal pathways will be used, such as:
• Conduits.
• Cable trays.
• Surface mounted trunking.
The sizing of the pathways will depend upon the number of cables and the size of the cables.
Work Area Outlet Requirements
The FTTO design and implementation shall be based on the industry standards and best
practices. The FTTO design uses micro switches with multiple ports exceeding the minimum
requirement of two telecommunications outlets/connectors per work area. Each micro switch
may serve one or two work areas and has a two-strand optical fiber cable in the horizontal
cabling as permanent link. The FTTO design follows the centralized cabling with splicing
in the TR or in a wall mounted enclosure. The optical fiber cable to the micro switch can be
terminated either:
• In a work area telecommunications outlet box with suitable optical fiber connector and
adapter.
• Directly with an optical fiber connector for direct connection to the micro switch based on
the MPTL concept.
Design Considerations for FTTO Deployment
Backbone Optical fiber Cabling
One or more backbone optical fiber cables such as 24-, 48-, 96-, or 144-strand cable shall
be used per floor or zone and be spliced to the 2-strand horizontal cable. The backbone
cable shall be terminated in the MC in the ER using approved optical fiber connectors and
termination methods.
Horizontal Optical Fiber Cabling
Two-strand optical fiber cable shall be used in horizontal. It will be spliced onto the backbone
cable on one end and terminated in a work area telecommunications outlet box or directly
with a connector on the other end.
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Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Design Considerations for FTTO Deployment, continued
Telecommunications Space
The FTTO design is based on the centralized cabling concept with splicing of the horizontal
cable to the backbone cabling. The splice enclosure can be located in a TR or TE.
Core and Distribution Switches
The FTTO design uses core and distribution switches in the equipment room and the micro
switches in work areas. There are no other active network equipment in the floor serving TR.
The type and configuration of the core and distribution switches will depend upon the number
of micro switches and the redundancy required.
Fiber-to-the-Office (FTTO) Installation Methods
The FTTO micro switch can be installed in the work areas using various accessories to suit
the work area environment and the cabling pathways, including:
• In wall.
• Surface mounted raceway.
• U nderfloor.
• Desk installation.
• Room pillar.
• Concealed installation.
There are various installation components used for each of these work area environments.
Power and Cooling Requirements
The FTTO design is based on centralized cabling topology with the centralized electronics
(e.g., core switches, distribution switches) in the ER and the micro switches in the work areas.
The FTTO design does not use any active equipment in the floor TR or TE. There is no need
for any cooling in the TR which reduces energy consumption.
The micro switches require de power input. They are powered by either of two methods:
• de power from a centralized power source located at a consolidated location.
• acto de power adaptor which will be located adjacent to the micro switch and powered by
a UPS.
Redundancy Design
The FTTO design uses redundancy concepts to ensure the highest possible availability. l'hese
redundancy concepts are unique to the FTTO design which makes the FTTO the preferred
design for critical networks requiring high availability and redundancy.
There are four variants of redundancy possible in the FTTO design.
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Chapter 5: Horizontal Distribution Systems
Redundancy Design, continued
Variant 1: Classical FTTO with cascading via bahmced twisted-pair cable
With FTTO, a micro switch typically supplies two work areas. It offers four copper ports
for work area equipment and is connected with the core switch via two optical fibers. It also
has a copper downlink pmi on the installation side. The simplest redundancy solution is to
connect two neighboring micro switches together via their copper downlink ports. Only a
standard balanced twisted-pair equipment cord to be routed in the cable duct for this purpose.
The copper connection is passively connected between the switches by means of the RSTP.
If an optical fiber connection to one of the two micro switches fails, then the tie line is
automatically activated via the balanced twisted-pair cable. Both micro switches and the work
area equipment connected therefore remain accessible in the network. The neighboring micro
switches are connected with different core switches to achieve fwiher redundancy.
Variant 2: Classical FTTO with cascading via optical fiber cable
Each micro switch is equipped with two optical fiber ports. Two neighboring micro switches
are cascaded using optical fiber cable. The advantage of this solution is that the optical fibers
are used consistently as cabling medium.
Variant 3: Dual homing-Double optical fiber connections
Each micro switch has two mutually independent optical fiber ports as in Variant 2 but is
connected directly with two independent core switches-preferably via separate paths to
achieve increased security. ff a link to a core switch drops out, then the data traffic simply
runs via the other. In this variant, everything is implemented twice, apart from the micro
switch. In the event of failure of a link, the full link performance of the micro switch is
maintained, as the second link to the other core switch is activated.
Variant 4: Dual homing-Single optical fiber connection
As with classical dual homing, the micro switch for dual homing with single fiber has two
mutually independent optical fiber connections. However, in this concept only a single strand
fiber is required for a link. The bidirectional SFPs send and receive via the same Hber at
different wavelengths. Through the use of just one fiber strand rather than two strands for
a link, only half the optical fibers are needed compared with classical dual homing, so the
overall cabling work is halved. Optical fibers, splices, and patch panels are needed half as
much, which has a positive effect in the filling level of cable pathways and cable routes.
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Chapter 5: Horizontal Distribution Systems
Passive 0
I Networks
Overview
A PON is a point-to-multipoint network architecture in which unpowered optical splitters
are used to enable a single optical fiber strand to serve multiple end-points. Passive optical
LANs are an implementation of PON technology for the enterprise LAN
(e.g., large Layer 2 Ethernet networks).
PON technology has successfully matured into a true enterprise network architecture capable
of delivering voice, data, and video services to the end user via a single strand of singlemode
optical fiber cabling. A PON solution reduces physical cabling infrastructure, minimizes
the telecommunications space requirements through the use of passive optical splitters, and
reduces electrical power and HVAC requirements in the floor serving TR.
Figure 5.23 illustrates the comparison of a traditional active Ethernet design to that of a
PON-based architecture.
Figure 5.23
Traditional active Ethernet design compared with PON-based architecture
Traditional I_AN
Passive optical network
•
...............................
1x32 splitter
(TR based splitter)
Singlernode or rnultirnode-;o......._
optical fiber backbone
...................
~
................................ ·r
...
Rack mounted ONT
SM fiber riser
GPON =
OLT =
ONT =
SM =
TR =
WAN=
Gigabit passive optical network
Optical line terminal
Optical network terminal
Singlemode
Telecommunications room
Wide area network
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Chapter 5: Horizontal Distribution Systems
Overview, continued
There are numerous PON infrastructure design options based on end user requirements,
pathway and space availability, and cabling approaches that are further defined in this section.
However, the primary components for PON architectures will remain constant with adherence
to BICSI best practices for cabling design and implementation. Installation of PONs should
follow these best practices as closely as possible to limit telecommunications infrastructure
and architecture issues and maximize potential service delivery options.
PONs are available in multiple variations based on standards for both gigabit and
I 0 Gb connectivity to the end user. The primary variations include:
• BPON (legacy technology).
• GPON.
• EPON.
• IOGPON.
• lOG-EPON.
The technical differences and nuances of each type of PON are outside of the scope of
this section and can be researched online by reviewing the appropriate technical standards
documents (see Table 5.4).The cabling infrastructure architecture and implementation
guidelines remain the same for all PON variations.
Table 5.4
Primary PON variations and their source standards
GPON
ITU G.984
EPON
IEEE 802.3ah
IOGPON
ITU G.987
lOG-EPON
IEEE 802.3av
EPON = Ethernet passive optical network
GPON = Gigabit passive optical network
ITU =International Telecommunication Union
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Chapter 5: Horizontal Distribution Systems
Wave Division Multiplexing (WDM) Fundamentals
PONs use WDM technology, which multiplexes optical carrier signals onto a single
optical fiber strand by using different wavelengths of laser light. This enables bidirectional
communications over one strand of optical fiber as well as multiplication of capacity.
WDM transmission requires singlemode optical fiber cabling.
Fiber Requirements
PONs utilize simplex, singlemode optical fiber cabling infrastructure. The PON signal
traverses from either a static fiber interface or a hot swappable SFP module at the head end
OLT, which provides the electrical to optical interface, to the end termination point at the
ONT.
The simplex singlemode optical fiber strands are then split using a passive optical splitter,
which provides between two and 64 simplex optical fiber outputs, and can terminate at the
desktop, on cabinet- or rack-mounted devices, or an outdoor ONT device. The ONT provides
the optical to electrical conversion back to useable voice, data, and video signals. It is
important to note that the connection point at the OLT is commonly a SCUPC type simplex
connector. The introduction of a third wavelength via WDM is used for RF over glass that
requires all other connection points at any intermediate fiber distribution panel, passive
optical splitter, and subsequent ON'T' to be subscriber connector APC to mitigate the effects
ofrellected light (i.e., back reflections).
It is recommended that APC connectors be utilized. The requirements for both current
Rl<' injection and current 1OGPON and lOG-EPON solutions implies that the end-to-end
optical fiber cabling link shall use APC connections to reduce back reflection in the
1500 11111 and above wavelength range.
With the extended distances provided by using a PON solution, it is common to have many
optical fiber distribution and demarcation points to transition from OSP to ISP cabling or
from backbone to horizontal cabling. At these locations, it may be advantageous to offer a
more compact solution that utilizes APC-type connectors. The PON signal is transparent to
the connectors utilized, except at the OLT and ONTs. Some solutions may require a highdensity fiber design, enabling the use of an MPO connector.
NOTE: For more information on these optical fiber connectors, see
Chapter 6: TCT Cables and Connecting Hardware.
Enterprise Passive Optical Network (PON) Hardware Active Components
Optical line Terminal {OlT)
The OLT is commonly referred to as the aggregation point of a PON architecture. The OLT
provides multiple high-bandwidth I Gb/s and 10 Gb/s interfaces via pluggable optics to the:
• Customer WAN or core network.
• PON switch fabric.
• PON interface cards.
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Enterprise Passive Optical Network (PON) Hardware Active Components,
continued
This, in turn, provides the singlemode fiber outputs to the splitters and maintains management
of the entire PON system. The OLT implements and manages the various network and
security protocols such as simple network management protocol, link layer discovery
protocol, Pol:, network switch port, and port security.
Optical Network Terminal (ONT)
The ONT is the user interface to the PON and contains the active component for the simplex
singlemode fiber termination and the optical to electrical interface to hand off the signaling
required for the end user connections. ONTs are available in many diJTerent options. New
ONT offerings, form factors, and innovative designs are constantly being developed and
deployed to meet customer requirements. Commonly deployed enterprise PON ONTs
include:
• 4-port desktop ONTs that provide a combination of four ports of 10/100/1000 Mb/s data
connections, PoE, RF coaxial ports, and POTS interfaces.
• Faceplate style ONTs capable of providing combinations for GbE and PoE interfaces.
Rack- or cabinet-mounted ONTs allow the reuse of existing horizontal category cabling
(e.g., category 5e/class D or higher). Rack- or cabinet-mounted ONTs are often used to power
devices such as WLAN APs, edge-based access control systems, megapixel IP surveillance
cameras, and others that do not have ac power available. These ONTs are currently available
with:
• I 0/ I 00 and 10/ I 00/ l 000 Mb/s Ethernet ports.
• 8, 16, and 24 device port configurations with and without PoE and PoE+ across some or all
of the ports.
SFP-based ONTs permit the singlemode optical fiber PON link to be directly connected
into an SFP, which can be inserted into an optical fiber network interface card of a server,
computer, or switch.
Enterprise Passive Optical Network (PON) Hardware Passive Components
Singlemode Optical Fiber and Connector Requirements
All OLT to ONT communications occur over a bidirectional simplex singlemode optical
fiber cabling infrastructure. Fiber infrastructure deployed for PONs support future PON
applications and bandwidth requirements with minimal cabling infrastructure upgrades.
All singlemode optical fiber connections in a PON past the OLT should be installed with an
APC. This reduces back retlections and allows for proper transmission of the 1550 nm and
above wavelengths of both the injected RF video streams and the standardized lOGPON and
IOG-EPON solutions.
The maximum supported distance of a PON varies from ::::::20.1 km ( 12.5 mi) to
::::::60 km (37 mi), depending primarily upon the loss budget of the PON type. The maximum
channel attenuations for the common types of PON technologies are listed in Table 5.5.
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Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Enterprise Passive Optical Network (PON) Hardware Passive Components,
continued
Table 5.5
Maximum channel attenuation and supported distance for PON versions
Passive Optical
Network Version
Maximum Channel
Attenuation
Supported
Max Distance
IEEE 802.3 EPON
20dB
::::;JO km (6.2 mi)
IEEE 802.3av lOG-EPON
29 dB
:::::;20.1 km ( 12.5 mi)
ITU G.984 GPON (B+ Optics)
28 dB
:::::;20.1 km (12.5 mi)
ITU G.984 GPON (C+ Optics)
32 dB
:::::;60 km (37 mi)
ITU G.987 lOGPON
31 dB
:::::;40 km (25 mi)
EPON = Ethernet passive optical network
GPON = Gigabit passive optical network
ITU = International Telecommunication Union
For passive optical LANs, maximum channel attenuation is also dependent on application.
Standards, such as ANSI/TIA-568.0, provide both minimum and maximum channel
attenuation. These values shall be used for passive optical LANs within a building.
Passive Optical Splitters
The passive aspect of a PON resides in the splitter. This device provides the ability to split the
single fiber output from each PON link exiting the OLT to a variety of splitter ratio outputs,
each terminating at the ONT. The splitter output ratios include:
• 1:2
• 1:4
• 1:8
• l: 16
• 1:32
• 1:64
NOTE: Enterprise deployments are typically designed to 1:32 split ratios.
A passive optical splitter can be thought of as a prism, splitting the light to the indicated
number of outputs. These splitters are available from a number of manufacturers and can be
obtained in small cassette forms with pigtail inputs and outputs for connection into traditional
adapter panels as pre-terminated trunk style devices. This type of pre-terminated trunk style
device allows the horizontal output cables to be easily pulled from the unit via an MPO-type
assembly or in a standard I rack unit-type form factor with inputs and outputs appearing like
a traditional patch panel. All connections on a passive optical splitter should be made with
high-performance APC connectors.
Passive splitters are also available in dual input configurations, which allow the splitter to be
protected from dual PON sources for additional redundancy and high availability.
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Work Area Outlet Requirements
Any PON design and deployment shall follow BICSl and TlA best practices for cabling
installation. As a PON provides multiple interfaces per ONT that exceed the customary two
telecommunications outlet/connector requirement to a single work area, a simplex optical
fiber cabling connection serves as the permanent link of a PON. PONs commonly utilize a
zone-based cabling solution from a ceiling or floor zone box with pre-terminated simplex
singlemode optical flber cabling to the actual work area outlets. Since single and dual strand
singlemode optical fiber cabling costs about the same, some ICT distribution designers
implement a dual strand flber to each work area outlet to allow for any future growth or
potential desktop ONT redundancy options.
NOTE: Even though a PON requires only a single strand of singlemode optical fiber cabling,
the ICT distribution designer should consider two or more strands at the work area to
allow for future topology change.
Design Considerations for Telecommunications Space-Based Optical Network
Terminal (ONT) Deployments
Backbone fiber Requirements and Terminations
One backbone optical flber per OLT' PON port shall be used per TR. Since there are usually
32 users per PON port, spare capacity should be built-in for future usage. Also, two optical
fiber feeder strands to each splitter may be desired to support the redundancy option or for
future upgrades. With the design of optical fiber cable in increments of 12, the tubes and
ribbons should not be split or shared among TRs.
Horizontal Copper Requirements
From the ONT located in the telecommunications space (e.g., ER, TR, TE), horizontal
cabling shall not exceed ;::::;90 m (295 ft) to the telecommunications outlet/connector serving
the edge device (e.g., phone, computer, printer, camera) in order to support voice, data, and
PoE communications.
ONTs may support PoE standards for power delivery over the balanced twisted-pair
horizontal cabling infrastructure.
Voice over Internet Protocol (VoiP) and Analog Voice Delivery
PON manufacturers provide analog ports for POTS at the ONT. ONTs within the
telecommunications spaces can allow for bulk analog phones to support either POTS or VoiP
services via analog lines. 'rhese ONTs provide a session-initiated protocol conversion from
analog (at the end user handset) to TP (either a VoiP soft-switch/local session controller or
Class-5 TOM-based service) over the PON infrastructure.
Radio frequency (Rf) Video Distribution
Depending on the ONT deployed, RF video can be deployed over the same PON
infrastructure. The same video headend equipment is required for PON as for a video coaxial
network. However, if the ONT already has an F connector, the services can be overlaid onto
the singlemode optical fiber 1550 nm wavelength with a designated virtual LAN with no need
for additional cabling.
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Chapter 5: Horizontal Distribution Systems
Desktop-Based Passive Optical Network (PON) Solution Architectures
Telecommunications Spaces Requirements (Special Sizing
Considerations)
Depending on the architecture, a rack-, cabinet-, or wall-mounted solution can be
designed. lt is important to consider additional technologies that may be placed in a TR
(e.g., access control, video surveillance, intrusion detection). It is suggested that BTCSI best
practices for telecommunications spaces square footage space be reduced to a shallow TR
that acts as a backbone to horizontal fiber patch point rather than a space of active network
electronics. Because ofthe extended distance reach of a PON (referenced in ·n1ble 5.5), the
need for multiple TRs per floor can be reduced to a single TR of intermediate fiber patch
panels. This reduction in space can provide additional square footage for offices or storage.
Telecommunications Spaces Heating, Ventilation, and AirConditioning (HVAC) Considerations
With a PON, when only passive elements are located in a TR where the access switches
would be typically installed, there is no need to have an HVAC requirement to cool the
passive elements.
Horizontal Pathway Special Design Considerations
Some designs deploy factory pre-terminated fibers that use single connectors or MPOs.
Some fiber manufacturers have developed an ;::-;3 mm (0.12 in) cable jacket that houses
12 fibers, incorporating a 12 fiber MPO. This design allows for the ability to run large
amounts of cable in a small pathway. If a cable tray is still a requirement, the size of the
tray can be reduced because of the smaller diameter of the fiber compared with balanced
twisted-pair cabling. The cable tray should still be sized for future expansion.
Horizontal Fiber Distribution Splitter Configurations
Telecommunications space-based splitters can be implemented in several ways. Some optical
fiber manufacturers have developed a one rack unit solution available in different splitter
variations (e.g., one I x32, two l x 16, four I x 8). Other designs can be used with splitter
modules that fit into a four-rack unit housing, which can hold up to 24 l x32 or 2x32 splitters
or other splitter configurations. Some vendors have adapted the fiber to the premises OSP
fiber distribution hubs to house up to 18 1x32 splitters. These FDHs can be wall mounted or
installed in a cabinet or rack. It is important to verify mounting widths as some require
o:-::584 mm (23 in) rack mounts.
Zone Cabling-Based Splitters
Zone cabling splitters ofTer an alternative to traditional telecommunications spaces mounted
splitters. Since zone cabling splitters are located closer to the end user, this allows for a lower
optical fiber implementation cost. If rack space in the floor serving telecommunications
space is limited or running multiple strands of optical fiber cabling to a zone is not permitted,
placing the splitters in a ceiling-mounted or access floor-mounted enclosure close to the end
user outlet locations may be necessary. The splitters are recommended to be placed in an
approved enclosure to protect the fiber connections.
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Chapter 5: Horizontal Distribution Systems
Desktop-Based Passive Optical Network (PON) Solution Architectures,
continued
Planning for future Dual Input Passive Optical Networks (PONs)
and Geographically Diverse Cable Routing
Diverse cable paths can deliver survivability all the way to the splitter connected to the
OLT. There are ways to achieve the same redundancy with the use of dual input splitters at
the desired location of survivability, which allow for OLT-based geographic diversity of the
splitters and ONTs.
Power and Cooling Systems
Typical Optical line Terminal (OlT) Thermal Output and Cooling
Requirements
It is suggested that as telecommunications space sizes are reduced or eliminated for the
networking electronics, the associated HVAC also can be minimized. Most PON installations
will have no networking related equipment within the telecommunications spaces. Unless
additional telecommunications systems are being planned that require cooling, dedicated
HVAC zones can be eliminated as the telecommunications space will not have any equipment
that generates heat. Best practices should be followed for the design of the MC (CD) and data
center locations where the OCT's are housed. The OLls typically utilize 40 to 70 percent less
power than legacy core networking equipment, and the associated cooling systems can be
sized smaller. The lCT distribution designer should confer with the PON system equipment
manufacturer during the planning phases of the project to detennine the overall BTU output
ofthe equipment.
Desktop Optical Network Terminal (ONT) Remote and Backup
Powering Options
Remote powering of the ONT can be achieved through the combination of singlemode
optical fiber and balanced twisted-pair cabling contained under a single sheath called a
hybrid cable. An alternative to using the hybrid cable method is to run two separate cables
in parallel, creating a balanced twisted-pair cabling channel alongside the singlemode
optical fiber cabling channel. The power is introduced to the balanced twisted-pair cabling
in telecommunications spaces. The ONTs require de power input, transitioning from ac
to de at a consolidated location (zone box) or utilizing an ac/dc rectifier solution in the
telecommunications space and a multiple output, independently fused de/de power panel at
the CP. 'T'his removes the need for transformers at the location of the ONT and keeps this
solution a low-voltage option.
Optical Network Terminal (ONT) Battery Backup
Certain ONT's are available with integrated lithium ion batteries that can allow for a short
runtime (e.g., 5-30 minutes) based on the services being provided and the actual power draw
of any PoE devices at the desktop level.
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Chapter 5: Horizontal Distribution Systems
Section 1: Horizontal Cabling Systems
Power and Cooling Systems, continued
Campus-Based Outside Plant (OSP)
A PON solution is suitable for deployment in a campus environment because of the ability of
the OLT to transmit and receive signals between :::::;20.1 km ( 12.5 mi) and :::::;60 km (37 mi).
The OLT can be housed in a central location (e.g., a data center) using new or existing
singlemode OSP cabling that can reach the majority of buildings on most campuses.
PON manufacturers have developed technology to move the network to a redundant PON
port, card, or another OLT chassis if a loss of signal from the ONT is detected. ln order to
accomplish this, a 2x32 splitter will need to be installed in the network. If a building housing
an OLT loses power, the chassis fails, a PON port fails, or the backbone fiber connectivity
fails, the network automatically switches to the provisioned back-up.
Implementation Considerations
Administrative Record Keeping
Administrative labeling and record keeping of the PON system is important for establishing
and maintaining the PON cabling infrastructure. This includes:
• Utilization of a zone-based deployment topology.
• Accurate record keeping of cable pathways.
• Accurate record keeping of horizontal drop cable identifications from each splitter port.
• Accurate baseline maximum insertion loss (power loss) test reports.
Each of these items is crucial to the long-term management and reduced MAC mistakes and
problems of the network. Within the active management platform of a PON, the means to
match up the physical cabling identifications to the ONT assignments is crucial.
NOTE: Refer to Chapter 10: Telecommunications Administration for additional requirements.
Testing and Certification of a Passive Optical Network (PON)
Infrastructure
All optical fiber cabling within a PON installation should be tested for bidirectional loss at
1310 nm and 1550 nm wavelengths. This should be an end-to-end test, placing one end of
the tester at the primary PON singlemode optical fiber jumper cable that would connect to
the OLC through the splitter, and then allow for a reading to be taken on every drop cable at
each ONT. The test unit stays stationary at the OLT end while the remote is moved across all
splitter outputs. lt is important to note any major discrepancies in fibers on the same splitter.
Refer to Chapter 11: Field Testing of Structured Cabling for additional information.
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Horizontal Pathways
Overview
The requirements in this section arc based on commercially accepted best practices.
Horizontal pathways consist of structures that conceal, protect, support, and provide access to
horizontal cabling between the telecommunications outlets/connectors used to connect work
area equipment at the work area and HC (FD) in the serving ER, TR, or TE.
Pathway implementation involves the pathway for containment of or support of cabling as
well as related spaces (e.g., pull boxes) that aid in the installation and change of cabling.
When designing a building, the layout and capacity of the horizontal pathway system shall be
thoroughly documented in floor plans and other building specifications. The ICT distribution
designer is responsible for ensuring that these systems have built-in flexibility to
accommodate tenant movement and expansion. In addition, the lCT distribution designer
should design the horizontal pathway system to make the maintenance and relocation of
cabling as easy as possible.
The design of the horizontal pathway system should accommodate various types of
telecommunications cabling in support of multiple applications (e.g., voice, data, video).
When determining the type and size of the pathway, the ICT distribution designer should:
• Consider the quantity and size of cables that the pathway is intended to support.
• Allow for growth of the area served over the planning cycle.
NOTE: All design and construction for pathway systems shall meet or exceed applicable
codes, standards, regulations, and AHJ rulings.
Design Considerations
The ICT distribution designer should carefully select and design the types and layout of the
horizontal pathway systems. After a building is constructed, it may be more difficult to gain
access to horizontal cabling than to backbone cabling. As a result, it would likely take a great
amount of skill, effort, and time to make horizontal cabling changes.
It is important to consider the design's ability to:
• Accommodate cabling changes.
• Minimize occupant disruption when horizontal pathways are accessed.
In addition to providing for current occupant needs, the horizontal pathway system design
shall:
• Facilitate the ongoing maintenance of horizontal cabling.
• Accommodate future MACs to the cabling, equipment, and services.
• Allow for future growth of20 percent unless otherwise specified by the client.
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Sizing Considerations
The size requirements for horizontal pathways depend on the following considerations:
• Usable floor space served by the pathway
• Maximum occupant density (e.g., floor space required per individual work area)
• BAS density
• Cabling density (e.g., quantity of horizontal cables planned per individual work area)
• Cable diameter
• Pathway capacity (e.g., requires that fill factor be taken into account)
Usable floor Space
The usable floor space is generally considered the building area used by occupants for their
normal daily work functions. For planning purposes, this space should include hallways, but
not other common areas of the building (e.g., restrooms, utility closets).
Maximum Occupant Density
The standard floor space allocation used in a commercial office environment is commonly
defined as one individual work area for every ;:::;9.3 m2 (100 fF) of usable floor space.
NOTE: Tn cases where the work area density will be greater than one work area per
;:::;9.3 m2 (1 00 ft2) of usable floor space or where more than three telecommunications
outlets or connectors will be required for each work area, the pathway capacity shall
be increased accordingly.
Building Automation Systems (BAS) Density
The standard floor space coverage area estimated for each BAS is a BAS outlet or device
for every ;:::;23.2 m 2 (250 ttl) of total floor area. BAS serve both used and unused floor
space; therefore, the entire floor space should be taken into account when sizing horizontal
pathways.
NOTE: See Chapter 14: Building Automation Systems for more information about
BAS density.
Cabling Density
Pathway capacity for BAS should include one cable for each system or coverage area. lf the
equipment manufacturer permits multiple coverage areas per cable, then the pathway sizing
can be adjusted accordingly.
NOTE: If multiple coverage areas are served by a single cable, then multiple channels within
the same cable sheath are permitted. Sheath sharing may also be restricted based on
safety considerations, applicable codes, standards, regulations, and AHJ rulings.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Sizing Considerations, continued
Cable Diameter
The ICT distribution designer should consider the actual diameter of the telecommunications
cables before determining pathway size requirements. When cable diameters are not
known, the ICT distribution designer should plan based on worst-case modeling and future
considerations to avoid under sizing the cabling pathways.
Pathway Capacity
Most pathways are provided with design guidelines, including fill factors from the
manufacturer. Different types of pathways may offer unique requirements.
NOTE: Since some local codes specify the pathway fill factors, check all applicable codes,
standards, regulations, and AHJ rulings before selecting a type of pathway.
Other Pathway System Considerations
Telecommunications Outlets/Connectors
Back boxes shall be installed for telecommunications outlets/connectors
in fire-rated wall installations and shall be firestopped appropriately. Low-voltage mounting
brackets (e.g., mud ring or plaster ring, box eliminator) may be used where the wall is not fire
rated and are typically used for work associated with MACs.
Telecommunications outlet/connector boxes installed in drywall, plaster, or concrete block
wall are available in an array of shapes and sizes. The size of each telecommunications
outlet/connector box shall be of a size that is adequate to accommodate the type and density
of cabling to be installed.
Telecommunications outlet/connector boxes should not be placed back to back to serve
adjacent rooms. This can compromise the effectiveness of the wall as a sound barrier and as a
firestop.
face Plates
Suitable face plates shall be specified for all telecommunications outlet/connector boxes.
Face plates for wall-mounted telecommunications outlets/connectors shall be designed to fit
the connectors and the device they are being mounted on. The designer must ensure that the
selected face plates are the correct color, have the number of ports, and are the style and size
to attach to the outlet box and receive the outlet connectors.
Mounting Telecommunications Outlets/Connectors
When mounting telecommunications outlets/connectors, the guidelines of all applicable
codes, standards, regulations, and AHJ rulings should be followed. Some codes specify
telecommunications outlet/connector access area, which includes minimum and maximum
height AFF and side reach.
To provide uniform appearance and accessibility in the work area, telecommunications outlet
boxes should be mounted at the same height as the outlet boxes that provide electrical power.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Other Pathway System Considerations, continued
Avoiding Electromagnetic Interference (EMI)
Avoiding EMI is an important consideration in the design of cabling pathways. Providing
physical separation from sources of EMI for these elements of the telecommunications
infrastructure inherently provides separation of their contents (e.g., cable and connecting
hardware).
The ICT distribution designer should locate telecommunications pathways away from sources
of EMI, including:
• Electrical power cabling and transformers.
• RF sources.
• Large motors and generators.
• Induction heaters.
• Arc welders.
• X -ray equipment.
• Photocopy equipment.
NOTE: For complete design and installation guidelines concerning EMI and RFT, including
equipment or system typical power factors and minimum separation distances from
possible sources of EMI and RFI, and any other guidelines, refer to
Chapter 2: Electromagnetic Compatibility.
Bonding and Grounding (Earthing)
Improper bonding and grounding (earthing) of telecommunications pathways may pose
a serious safety risk. The term improper is used here to describe bonding and grounding
(earthing) that is either not present or present and is not designed or installed properly. In
addition, improper bonding and grounding (earthing) may increase susceptibility to EM I.
NOTE: For details on bonding and grounding ( eatthing) requirements, refer to
Chapter 8: Bonding and Grounding (Earthing).
Administration
The lCT distribution designer should use systematic methods and procedures for labeling and
managing horizontal pathways and spaces.
NOTE: For guidelines and requirements for the color-coding and administration of horizontal
cabling systems, refer to Chapter 10: Telecommunications Administration.
Firestopping
All horizontal pathways that penetrate fire-rated barriers shall be firestopped in accordance
with applicable codes.
NOTE: For further details on firestopping, refer to Chapter 7: Firestop Systems.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Other Pathway System Considerations, continued
Wet locations
A building's horizontal pathways shall be installed in locations that protect cabling from
the moisture levels beyond the intended operating range of interior premises cabling. For
example, slab-on-grade construction where pathways are installed underground or in concrete
slabs in direct contact with soil (e.g., sand, gravel) is considered a wet location. When faced
with such design environments, fCT distribution designers should design pathway or cabling
systems that are suitable for use in wet locations (e.g., cabling products are often described as
industrial cabling products).
NOTE: 'fhe ICT distribution designer should consult applicable codes, standards, regulations,
and AHJ rulings for local definitions of damp location, dry location, and wet location.
Hazardous locations
When telecommunications horizontal pathways or cabling is placed in a hazardous location
(e.g., an explosive or combustible atmosphere), observe all applicable code requirements.
NOTES: See applicable codes, standards, regulations, and AHJ rulings for local definitions
of hazardous locations. Refer to Appendix A: Codes, Standards, Regulations, and
Organizations at the end of this manual for more information about regulatory
requirements.
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Types of Horizontal Pathways
Overview
Horizontal pathways include:
• Underfloor ducts.
• Cellular floors.
• Conduits.
• Cable trays.
• Access t1oors.
• Ceiling distribution.
• Surface-mounted raceways.
• Work area pathways.
• WLANAPs.
NOTE: See Chapter 16: Wireless Networks for more information about WLAN APs.
Many buildings require a combination oftwo or more types of pathway systems to meet all
distribution needs. For example, an office area in a building may require an underfloor or
overhead system, while an isolated telecommunications outlet/connector location in the same
building may be best served by an individual conduit.
NOTE: Because some codes specify the type of horizontal pathway to be used, check all
applicable codes, standards, regulations, and AHJ rulings before selecting a type of
pathway.
Conduit Distribution Systems
A conduit system consists of conduits installed from the applicable telecommunications space
(e.g., ER, TR) to the telecommunications outlets/connectors in the floors, ceilings, walls,
columns, or furniture in a building (see Figures 5.24 and 5.25).
Figure 5.24
Underfloor conduit extended to individual telecommunications outlet boxes
Telecommunications room
/
Wall~
outlet
boxes
~
\¥1
uP
1111
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Conduit Distribution Systems, continued
Figure 5.25
Typical underfloor conduit system
)
I
--~~-~~
- ------
Conduit
~~::=:;::;::;::;
stubbed ___-+rrL------~~
into TR
floor
- -
- =Conduit
~ =Telecommunications outlet box
TR =Telecommunications room
Suitability and Acceptability of Conduits
The ICT distribution designer should design and install conduit runs:
• To achieve the best direct route (e.g., usually parallel to building lines) with no single bend
greater than 90 degrees or an aggregate of bends in excess of 180 degrees between pull
points or pull boxes.
• That do not contain continuous sections longer than ;:o;30.5 m ( 100 ft). For runs that total
more than ;:o;30.5 m ( l 00 ft) in length, pull points or pull boxes should be inserted so that no
segment between points or boxes exceeds the ;:o;30.5 m ( 100 ft) limitation.
• Bonded to ground on one or both ends in accordance with national or local code
requirements.
• That can withstand the environment to which they will be exposed.
• To avoid areas over or adjacent to heat sources such as:
Boilers.
- Incinerators.
- Hot water lines.
- Steam Iines.
NOTE: Refer to Chapter 4: Backbone Distribution Systems for information on types of
conduit.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Conduit Distribution Systems, continued
Conduit Body
A conduit body is a conduit coupling that has a removable cover to allow access to the
cable for placing purposes (see Figure 5.26). It is primarily used to give access to or to
change the direction of the conduit system. It is important to meet the minimum bend radius
requirements when cables are installed into a conduit system and conduit bodies are used to
change direction.
IMPORTANT: Standard conduit bodies do not meet the recommended bend radius and shall
not be specified for TCT cable installation.
A conduit body features an internal radius that accommodates a standards-based cable
bend radius once cable is installed in the lay position of the conduit body device. Only the
telecommunications cabling style conduit bodies should be used in a telecommunications
cabling installation.
The most common styles are the:
• 90-degree bend lett, right, or back.
• T configuration.
• C or straight inline fitting.
Figure 5.26
Conduit bodies recommended for telecommunications cables
Elbow back (LB)
Elbow right (LR)
T conduit body
Telecommunications cabling
style conduit body
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Conduit Distribution Systems, continued
In some buildings, a conduit system can furnish cable support and concealment. ln such
installations, conduit bodies manufactured to provide ample room for telecommunications
cables may be used to enable access to the cabling (e.g., C conduit bodies) or to enable access
to the cabling with a 90 degree corner (e.g., elbow left, elbow right, elbow back conduit
bodies).
Conduit bodies designed for use with electrical wiring systems are not recommended for use
with telecommunications cabling. Conduit bodies designed for use with telecommunications
cabling systems that provide standards-based internal bend radii may be used where
applicable.
ICT distribution designers shall consider codes, standards, regulations, and AHJ rulings, as
well as aesthetics and other customer needs, when designing any conduit system.
Capacity
To ensure proper capacity for cabling, a conduit from the TR should not extend to more than
two and shall not extend to more than three telecommunications outlet boxes.
Conduit size is generally designed so its diameter increases incrementally as the run
approaches the ER or TR from the farthest telecommunications outlet box.
'I'he conduit size for horizontal cabling shall accommodate cables placed at different times.
To determine the cross-sectional area of a cable or conduit from its nominal diameter, use the
following formula (where d =diameter):
Cross-sectional area= 0.785 x d 2
For conduit terminated at smoke- or fire-rated partitions, design to meet the firestop listed
assembly. lf fill percentage is too high, then there may not be enough space to install the
correct amount offirestop material to perform its intended duty.
NOTE: For cables with an elliptical cross section, use the larger diameter of the ellipse as the
diameter in the equation above.
Tables 5.6 and 5.7 provide guidelines and recommendations on conduit fill for horizontal
cabling, assuming that a straight run of conduit is used and no conduit bends are applied.
The tables offer conduit sizes ranging from ;:;:;16 mm ( 1/2 trade size) to;:;:; I 03 mm
(4 trade size).
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TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Conduit Distribution Systems, continued
Table 5.6
EMT 40 percent conduit fill rate
Trade
Size
metric
designator
Conduit 1D
mm (in)
4.6mm
(0.18 in)
112
16
15.8
(0.622)
3
2
2
3/4
21
20.93
(0.824)
6
5
3
2
2
2
27
26.65
(1.049)
10
8
5
4
3
3
1 1/4
35
35.05
( 1.380)
17
14
9
7
5
5
1 l/2
41
40.89
(1.610)
24
19
13
9
8
8
2
53
52.5
(2.067)
39
32
22
16
13
13
2 1/2
63
62.71
(2.469)
56
45
31
23
19
19
3
78
77.93
(3.068)
87
70
49
36
29
29
3 l/2
91
90.12
(3.548)
116
94
65
48
39
39
4
103
102.3
(4.026)
150
121
84
62
50
50
S.Omm
(0.20 in)
6.0mm
(0.24 in)
7.0 mm 8.0mm 9.0mm
(0.28 in) (0.31 ill) (0.35 in)
0
NOTE: The calculations used in Table 5.6 to determine cable fill are based on a 40 percent
initial fill factor assuming straight runs with one 90 degree bend. These conduit
sizes are typical in the United States and Canada and may vary in other countries.
The metric trade designators and imperial trade sizes are not literal conversions of
metric to imperial sizes. This table shall not be used when penetrating a smoke or fire
barrier, the appropriate Listed Assembly instruction sheet shall be used to determine
fill ratio.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Conduit Distribution Systems, continued
Table 5.7
Typical EMT conduit fill rate for varying cable diameters
metric
designator
l/2
16
15.8
(0.622)
4
3
2
3/4
21
20.93
(0.824)
8
6
4
3
2
2
27
26.65
( 1.049)
13
11
7
5
4
4
1 l/4
35
35.05
( 1.380)
23
19
13
9
7
7
I 1/2
41
40.89
( 1.61 0)
32
25
18
13
10
10
2
53
52.5
(2.067)
52
42
29
21
17
17
2 1/2
63
62.71
(2.469)
75
60
42
31
25
25
3
78
77.93
(3.068)
116
94
65
48
39
39
3 1/2
91
90.12
(3.548)
155
125
87
64
52
52
4
103
102.3
(4.026)
200
162
112
82
67
67
Conduit lD
mm (in)
4.6mm
(0.18 in)
().0 mm
(0.24 in)
Trade
Size
5.0mm
(0.20 in)
7.0mm 8.0 rnm 9.0mm
(0.28 in) (0.31 in) (0.35 in)
NOTE: The calculations used in Table 5. 7 to determine cable fill are based on a 40 percent
initial fill factor assuming straight runs with one 90 degree bend. These conduit sizes
are typical in the United States and Canada and may vary in other countries. The
metric trade designators and imperial trade sizes are not literal conversions of metric
to imperial sizes. This table shall not be used when penetrating a smoke or fire
barrier, the appropriate Listed Assembly instruction sheet shall be used to determine
fill ratio.
'T'he higher the conduit's percentage fill, the more friction, resulting in stress that is applied
to the cables in the conduit. This cable friction and resulting stress may be amplified when
conduit bends occur throughout a section of conduit without a pull point.
See Tables 5.8 and 5.9 for conduit with one and two bends, respectively.
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Conduit Distribution Systems, continued
Table 5.8
Conduit fill with 1 bend
Conduit ID
mm (in)
4.(j mm
(0.18 in)
Trade
Size
metric
designator
112
16
15.8
(0.622)
4
3
2
3/4
21
20.93
(0.824)
7
5
4
2
27
26.65
(1.049)
ll
9
6
4
.)
3
1 1/4
35
35.05
(1.380)
19
16
11
8
6
5
1 1/2
41
40.89
(1.610)
27
22
15
11
9
7
2
53
52.5
(2.067)
44
36
25
18
15
I1
2 1/2
63
62.71
(2.469)
63
51
35
26
21
16
3
78
77.93
(3.068)
98
80
55
40
33
26
3 l/2
91
90.12
(3.548)
132
106
74
54
44
34
4
103
102.3
(4.026)
170
137
95
70
57
44
S.Omm
(0.20 in)
6.0mm
(0.24 in)
7.0mm 8.0mm 9.0mm
(0.28 in) (0.31 in) (0.35 in)
2
,
NOTE: The calculations used in Table 5.8 to determine cable fill are based on a 40 percent
initial fill factor assuming straight runs with one 90 degree bend. These conduit sizes
are typical in the United States and Canada and may vary in other countries. The
metric trade designators and imperial trade sizes are not literal conversions of metric
to imperial sizes. This table shall not be used when penetrating a smoke or fire
barrier, the appropriate Listed Assembly instruction sheet shall be used to determine
fill ratio.
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Conduit Distribution Systems, continued
Table 5.9
Conduit fill with 2 bends
Trade
Size
met de
dcsianator
112
16
15.8
(0.622)
3
2
3/4
21
20.93
(0.824)
5
4
3
2
27
26.65
(1.049)
9
7
5
3
3
2
1 1/4
35
35.05
( 1.380)
16
13
9
6
5
4
I l/2
41
40.89
(1.610)
22
18
12
9
7
5
2
53
52.5
(2.067)
36
29
20
15
12
9
2 1/2
63
62.71
(2.469)
52
42
29
21
17
13
3
78
77.93
(3.068)
81
65
45
33
27
21
3 112
91
90.12
(3.548)
108
88
61
44
36
28
4
103
102.3
(4.026)
140
113
78
57
47
37
"'
Conduit lD
mm (in)
4.6mm
(0.18 in)
5.0mm
(0.20 in)
6.0mm
(0.24 in)
7.0mm 8.0mm 9.0mm
(0.28 in) (0.31 in) (0.35 in)
0
NOTE: The calculations used in Table 5.x to determine cable fill are based on a 40 percent
initial fill factor assuming straight runs with two 90 degree bends. These conduit
sizes are typical in the United States and Canada and may vary in other countries.
The metric trade designators and imperial trade sizes are not literal conversions of
metric to imperial sizes. This table shall not be used when penetrating a smoke or fire
barrier, the appropriate Listed Assembly instruction sheet shall be used to determine
fill ratio.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Conduit Distribution Systems, continued
In the following examples, a I 5 percent derating factor was applied to the conduit fill
recommendations offered in order to accommodate the effects of friction and resulting cable
stress that typically occurs with cabling installation in commercial building applications.
The following formula may be used to derate the number of cables in a conduit:
.t fill d
Con d u1
t.
era mg
[conduit cross-sectional area] x (1 -[number of conduit bends]
[cable cross-sectional area]
=
x 0.15) x 0.4
The derating example is for an ;:::;41 mm (1-112 trade size) conduit with one 90-degree bend
and an ;:::;8 mm (0.31 in) OD cable.
The cross-sectional area of conduit and cable is determined using the formula:
2
A
pi*d /4
A
Resulting cross-sectional area
pl
3.14
Where:
d
Cable outside diameter or conduit internal diameter.
Examples:
Conduit fill derating, in millimeters:
AcondUit.x(l-lx0.15)x0.4/Acnblc
1320 X (I - I X 0.15) X 0.4/50.2
1320 X (I - 0.15) X 0.4/50.2
1320 X 0.85 X 0.4/50.2
448.8/50.2 =
8.9 ~ 9 (cables)
Conduit fill derating, in inches:
A condu1t. X (1- 1 X 0.15) X 0.4/Acable
2.04 X (I - I X 0.15) X 0.4/0.075
2.04 X (1 - 0.J5) X 0.4/0.075
2.04 X 0.85 X 0.4/0.075
0.694/0.075 =
9.25 ~ 9 (cables)
In this example, the cable derating formula resulted in a reduction to nine cables from
twelve cables as shown in 'T'able 5.6. The difference in results between the metric expression
and imperial expressions used in the examples above may be explained because of
slight variables in metric to imperial conversions of conduit internal diameter and cable
outside diameter. The mathematical results have been rounded up or down to the nearest
corresponding round value.
Cable pull force should be monitored closely during the installation to ensure that the
manufacturer's cable pull force requirements are not exceeded.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Conduit Distribution Systems, continued
Size
Cable pull force is determined by several factors, including the:
• Cable type.
• Conduit type.
• Conduit diameter.
• Conduit length.
• Conduit layout.
• Number and configuration of conduit bends.
• Selection of lubricants used during the installation.
When a complex installation is anticipated, specifying the use of a breakaway swivel
equipped with an appropriate shear pin is recommended.
Examples of complex installations include an increased cable load because of:
• Cable pulled through conduit runs longer than ;:::;30.5 m (100ft).
• Conduit with more than one bend.
Because of the possibility of damaging existing cables and other uncertainties, pulling
additional cables through a partially filled conduit is generally not desirable. Lubricant should
be specified, taking into consideration compatibility with cable jacket composition, safety,
lubricity, adherence, stability, drying speed, and cable manufacturer's recommendations. The
way a lubricant dries should also be a factor as some lubricants dry as a solid substance.
© 2020 BICSJ:®
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TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Conduit Distribution Systems, continued
The following is a sample calculation to determine the size of a horizontal conduit based on
the preceding information and guidelines.
Step
Task
Example
Measure the usable floor space to be
served by the horizontal conduit.
~93m 2
2
Divide the usable tloor space by the
maximum occupant density required
per individual work area.
~93m 2
3
Multiply the result by the maximum
number of cables per individual work
area.
4
5
(1001 ft")
(1001 ft 2)
~ 9.3 m 2 (I 00 ft 2 )
I 0 individual work areas
x
10 individual work areas
3 cables per individual
30 cables
Determine the maximum diameter of
the horizontal cable to be used.
(Telecommunications cables of different
types may be placed together in the
same conduit.)
~
Use Table 5.5 to determine the minimum
conduit size for holding a quantity
of30 cables with a diameter of~6.1 mm
(0.24 in).
'I'rade size 2
6.1 mm (0.24 in)
Bend Radii
Choose the bend radii for conduits as shown in Table 5.10.
Conduit bends should be smooth, even, and free of kinks or other discontinuities that may
have detrimental effects on pulling tension or cable integrity.
Table 5.10
Bend radii guidelines
Cable
Minimum Radii
'T'rade size diameters greater than
53 mm (2 in) or when used for
optical fiber
Inside bend radius shall be 10 times the
internal diameter of the conduit
Trade size diameters 53 mm (2 in)
or less
Inside bend radius shall be 6 times the
internal diameter of the conduit
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Conduit Distribution Systems, continued
Table 5.11
Adapting designs
If a Conduit Run Requires ...
Then ...
More than two 90 degree bends
Provide a pull point or pull box between
sections with two bends or fewer.
A reverse bend (i.e., between l 00 degrees
and 180 degrees)
Insert a pull point or pull box at each bend
having an angle from I 00 degrees to
180 degrees.
A third bend may be acceptable in a pull section without derating the conduit's capacity if one
of the statements below is true:
• The total run is not longer than::::; I 0 m (33 ft).
• The conduit size is increased.
• One of the bends is located within ::::;JOO mm ( 12 in) of the cable feed end.
This exception only applies to placing operations where cable is pushed around the first bend.
Conduit Terminations
All conduit ends should be reamed and fitted with a suitable bushing to eliminate sharp edges
that can damage cables during installation or service.
Conduits that enter a telecommunications space should terminate near the corners to allow for
proper cable racking. These conduits should terminate as close as possible to the wall where
the backboard is mounted to minimize the cable route inside the telecommunications space.
Terminate conduits that protrude through the structural tloor ::::;25 mm ( 1 in) to
::::;77 mm (3 in) above the surface. This prevents cleaning solvents or other fluids from
flowing into the conduit.
NOTE: Maintain the integrity of all firestop barriers for all floor and wall penetrations. For
terminations of conduits entering a building, sec Chapter 3: Telecommunications
Spaces and Chapter 7: Firestop Systems.
ERs and TRs should not have a suspended ceiling. However, if a suspended ceiling is present,
it should be higher than any cable entry point in the room. This may minimize the number of
bends required in a conduit, cable tray, ladder, or other cabling pathway system.
Completing Conduit Installation
After the installation, conduits should be left:
• Clean, dry, and unobstructed.
• Reamed and fitted with bushings.
• Capped for protection.
• Labeled for identification.
A 11 conduits should be equipped with a pull cord that has a minimum test rating of
::::;889 N (200 lbf).
© 2020 BICSI®
TDMM, 14th edition
Section 2.: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Pull Points and Pull Boxes for Conduits
NOTE: The following information applies to inside plant cabling only.
The TCT distribution designer should use the following design criteria:
• Pull points and pull boxes should be placed in easily accessible locations.
• Pull points or pull boxes should be placed in sections of conduit that are ;::::;30.5 m ( 100 ft) or
longer or per the specific criteria of Table 5.8
• Conduits should enter the pull point or pull box from opposite ends with each other and
should be aligned. Figure 5.27 shows recommended pull box configurations.
Figure 5.27
Recommended pull box configurations
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Pull Points and Pull Boxes for Conduits, continued
A pull point or pull box should be placed in a ceiling space only if the pull box is:
• Listed for that purpose.
• Placed above a suitably marked, removable ceiling panel.
Pull points or pull boxes should not be used for splicing cable or used in lieu of a bend.
Choosing a Pull Box Size
Selecting the proper size of pull box facilitates:
We should have this as notes
• Pulling cable into the box.
• Looping cable for pulling into the next length of conduit.
The minimum length of a pull box shall be at least 16 times the diameter of the largest
conduit entering the pull box. In some cases (e.g., when large cables arc planned to serve
multiple work areas), providing additional box length is recommended. Additionally, a pull
box shall have a width and depth adequate for fishing, pulling, and looping the cable.
Table 5.11 provides the typical pull box sizes dependent on the diameter of the conduit that
meets the minimum sizing requirement. Table 5.12 also provides guidance for increasing the
width of the pull box when multiple conduits are served on a side.
Table 5.12
Typical space requirements for pull boxes having conduit enter at opposite ends of the box
Conduit
Trade Size
::::::mm
(Trade Size)
Box
Width
::::: mm (in)
Box
Length
::::: mm (in)
Box
Depth
::::: mm (in)
Box Width Increase
for Each Additional
Conduit::::: mm (in)
27 (1)
100 (4)
400 (16)
75 (3)
50 (2)
35 (l-1/4)
150 (6)
508 (20)
75 (3)
75 (3)
41 (1-l/2)
200 (8)
686 (27)
100 (4)
100 (4)
53 (2)
200 (8)
900 (36)
100 (4)
125 ( 5)
63 (2-1/2)
250 (1 0)
1067 (42)
125(5)
150 (6)
78 (3)
300 (12)
1220 (48)
125 (5)
150 ( 6)
91 (3-l/2)
300 (12)
1370(54)
150 (6)
150 (6)
103 (4)
375(15)
1525 (60)
200 (8)
200 (8)
© 2020 BICSI®
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Pull Points and Pull Boxes for Conduits, continued
Slip Sleeves and Gutters
Slip sleeves and gutters:
• Can be used in place of a pull box.
• Will provide more space for pulling.
Slip sleeves and gutters should not be used as splice locations.
To allow access to the cable being installed, an opening that is long enough to form a cable
loop during the pulling-in operation should be provided in the main conduit when using slip
sleeves and gutters.
Table 5.13 describes slip sleeves and gutters.
Table 5.13
Slip sleeves and gutters
A ...
Is ...
Slip sleeve
A conduit sleeve that is:
• Larger than the main conduit.
• Slipped over one of the main conduit ends prior to
pulling cable, leaving the area between the two main
conduits open to be used as a pull point.
• Slipped back over cable opening joining the two
main conduits after the cable is in place.
Slip sleeve must be secured to prevent opening (usually
by placing conduit support hangers on main conduits
butted up against each end of the slip sleeve).
Gutter
TDMM, 14th edition
A sheet metal housing, sometimes referred to as a bus
duct, placed over an opening in a conduit run.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Underfloor Conduit Systems
The advantage of undcrfloor conduit systems is their low initial installation cost for areas
that have only a few telecommunications outlets/connectors. 'I'his is particularly true where
telecommunications outlet/connector locations are already established.
Undcrfloor conduits may be used to:
• Extend underfloor ducts to a telecommunication outlet/connector location on a wall or
column.
• Connect a baseboard raceway or movable partition raceway to a building cable distribution
system.
The disadvantage ofunderfloor conduit systems is their limited flexibility
(e.g., when making cable changes):
• They are costly to add in concrete floors.
• Cabling from work areas may be exposed if desks are not located:
-- Over floor-mounted telecommunications outlets/connectors.
Adjacent to wall-mounted telecommunications outlets/connectors.
Access Floor Distribution Systems
An access floor:
• Is raised above an existing subfloor.
• Provides accessible space under the floor panels.
• May be called raised floors.
• Is often used in computer rooms and ERs.
• May be available with combustible, noncombustible, and composite panels and can be
designed for seismic and other special conditions.
• Make use of an area below the finished floor that may be suitable for air-handling purposes.
Types
Two general types of access flooring are:
• Standard-height floors-- ;::;]50 mm (6 in) or higher (the most common type).
• Low-profile floors-Less than ;:::;J50 mm (6 in). They are often used where structural
limitations (e.g., insufficient slab-to-slab height) are encountered.
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Access Floor Distribution Systems, continued
Components
An access floor typically consists of:
• Steel footings that rest on the subfloor. These footings provide distributed support for floor
loads.
• Pedestals that support and interlock with lateral bracing (stringers) or panels. These
pedestals are evenly spaced on the steel footings and are adjustable to compensate for
unevenness of the subftoor.
• Floors that may or may not be constructed with stringers. When used, they are assembled
to form a framework of panel receptacles. These stringers provide lateral support by
interlocking with the pedestals.
• Modular floor panels that rest on the stringers or pedestals. Panel sizes typically range
from ::::::457 mm ( 18 in) to ::::::610 mm (24 in) square. Plain or carpeted panel surfaces may be
selected to accommodate the functional and aesthetic needs of the area they occupy.
Stringered Systems
Stringered systems have lateral bracing (stringers) between pedestal supports. When
stringered systems are used, they shall be bolted or snapped to the pedestal heads.
Stringered systems:
• Brace the pedestals for improved lateral stability.
• Provide additional support for the panels.
• Facilitate frequent removal and replacement of floor panels.
The basic components of a stringered access floor system are shown in Figure 5.28.
Figure 5.28
Stringered access floor system
~Steel
footings
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Access Floor Distribution Systems, continued
Freestanding and Cornerlock Systems
Freestanding and cornerlock access floors consist of panels that are supported solely by
pedestals.
Freestanding systems rest on pedestal supports with no mechanical fastening, whereas
cornerlock systems mechanically fasten floor panels to the pedestal heads at each corner. Of
the two, cornerlock systems add increased stability and are preferred for general office use.
Use of freestanding systems should be restricted to installations with finished heights of
:::::305 mm (12 in) or less.
Considerations for Access Floor Distribution
Minimum Finished Floor Height
For low-profile floors, cable or cable pathways shall be provided a clearance of at least
:::::19mm (0. 75 in). For standard-height floors, the minimum finished height of access flooring
depends on its use and location. When standard-height flooring is used in:
• General office areas-the finished floor shall provide at least :::::152 mm (6 in) minimum
clearance above the structural floor, with a recommended clearance of at least
:::::203 mm (8 in). Where multiple systems will be installed under the raised floor,
considerations should be given to minimum :::::305 mm (12 in) clearance above the
structural floor.
• An environment where the plenum is used for HVAC, the finished floor height shall be
:::::305 mm (12 in) or greater.
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Considerations for Access Floor Distribution, continued
Regardless of the height of the finished floor, a minimum of ;:::51 mm (2 in) of free space
should exist between the top of the cable tray side rails and the underside of the stringers
(see Figure 5.29). If cable trays with covers or raceways are used, the free space above the
tray should allow for easy removal of covers.
Figure 5.29
Recommended clearance for access floor spaces
I
-
I
2" clearance
I
Tray
Building Structure
When planning access flooring for new or existing buildings, the two common types of
building structures should be considered:
• Depressed slab--The area to receive the access flooring is depressed. The depth of
depression shall equal the height of the finished access floor to avoid the need for ramps or
steps.
• Normal slab- Where the slab is not depressed, provisions should be made for a structural
transition to the access floor. Building codes for ramp and step assemblies shall be followed.
NOTE: All design and construction for ramp and step assemblies shall meet or exceed
applicable codes, standards, regulations, and AHJ rulings.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Considerations for Access Floor Distribution, continued
Building Layout
The layout of the access floor should be designed before installing any equipment or
telecommunications cabling.
Whenever possible, the floor plan should be designed so that the telecommunications space
(e.g., ER, 'fR) is adjacent to the access floor area that it will serve. Threaded sleeves or
conduit should connect the telecommunications space to the access floor area.
In cases where the telecommunications space and the access floor area it serves are not
adjacent, other connection methods are required. In these cases, the interconnecting pathways
should adequately serve the access floor area.
Floor Penetrations
Penetrations through the access floor should be designed for the type and number of service
fittings required to support the telecommunications outlets/connectors. Cable egress or
telecommunications outlets/connectors should not be placed in traffic areas or other locations
where they may create a safety hazard.
The manufacturer's guidelines should be consulted to ensure compatibility between access
floor components and service fittings.
Firestop integrity should be maintained in all rated building structures that shall be penetrated
by cable or pathways. Consideration should be given to sealing floor penetrations to restrict
any air leakage.
Bonding and Grounding (Earthing)
All metal parts of an access floor should be bonded to ground. For bonding and grounding
(earthing), follow the access floor manufacturer's guidelines and all applicable codes.
NOTE: See also Chapter 8: Bonding and Grounding (Earthing).
Floor Panel Materials
Where cabling is not placed in a conduit, the panels shall be made completely of
noncombustible materials.
NOTES: All applicable codes, standards, regulations, and AHJ rulings should be met or
exceeded for compliance with flame spread and smoke index properties of t1oor
panels.
See Appendix A: Codes, Standards, Regulations, and Organizations at the end of
this manual.
For general offices, composite steel and concrete panels are popular because they:
• Are noncombustible.
• Can bear dynamic loads.
• Come close to sounding and feeling like an actual concrete slab t1oor.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Considerations for Access Floor Distribution, continued
Floor Panel Coverings
Floor panels are covered according to their intended use, as shown in Table 5.14.
Table 5.14
Coverings
Panels To Be Used in a(n) ...
Will Be Covered by .•.
Computer room
• High-pressure laminate, vinyl, or other durable tile.
Office
• Factory-laminated carpet or no material
(e.g., ready to receive carpet tiles).
load-Bearing Capacity
Access floors may be designed to bear different distributed loads and concentrated loads
according to the intended use of the room. Table 5.15 shows the load-bearing capacity of
access floors designed for ERs and office space.
Table 5.15
Load capacity
Application
Uniform Load Capacity
Concentrated Load Capacity
Equipment room
(medium duty)
;::;4.8 kPa ( 100 lbf/ft2)
;::;8.8 kN (2000 lbf)
General office
(medium duty)
Dynamic loads are also an important measure of access floor performance for both
distribution facilities and office applications. Dynamic loads are created by:
• Accidental impacts (e.g., falling objects).
• Rolling objects (e.g., paper catis, mail mobiles, other wheeled vehicles).
When designing an access floor, the maximum potential concentrated point load should
be determined. The ICT distribution designer should check with floor manufacturers to
determine both the rolling load and impact load ratings for their floor systems.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Specifying Access floor Pathways
Telecommunications cables in an access floor plenum should be placed in pathways that
provide sufficient space for service personnel to stand on the structural floor without
damaging the cable.
Grommets that are flush mounted in a floor panel or access door should be used to protect
work area cables that connect to concealed telecommunications outlets/connectors.
For cable management, the following methods of containment for main runs should be
considered:
• Dedicated routes
• Enclosed raceway distribution
• Cable trays
• Cable matting
NOTE: Applicable codes, standards, regulations, and AHJ rulings should be consulted for
compliance with flame spread and smoke index properties of cables used in cabling
pathway systems.
IMPORTANT: Connecting hardware or telecommunications equipment should not be placed
in the access floor space.
Electrical Power Circuits
NOTE: For separation requirements for electromagnetic isolation and safety from
telecommunications cabling, see Chapter 2: Electromagnetic Compatibility.
Effects of Underfloor Air Distribution on Cabling
The space under an access floor often may be used as a plenum for distributing conditioned
air throughout the room or, in some cases, the entire office area. When the plenum is
used for air distribution, applicable codes shall be followed for electrical power and
telecommunications cabling requirements.
lfthe space under an access floor is not used as an air-handling plenum, most codes allow
certain types of telecommunications cables to be run without special enclosure requirements.
This is also true for an above-ceiling interstitial space that is not used for air handling.
Proper placement of cable trays and telecommunications cabling in the space under an access
floor is essential to ensure that adequate airflow is maintained. The underfloor air space
should not be blocked by cable bundles, thereby causing air dams.
In office areas, code requirements may be different for telecommunications spaces
(e.g., ERs, TRs) where special fire suppression systems may be installed.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Effects of Underfloor Air Distribution on Cabling, continued
Advantages and Disadvantages
Many ICT distribution designers consider the access floor system the best distribution system
available. The advantages of access floor systems are that:
• They are aesthetically acceptable for office decor.
• They are designed for high capacity.
• Cabling is easily accessible across the entire J1oor.
• Changes can be made quickly with little occupant disruption.
• They are among the least costly of all distribution systems for making MACs.
• Cabling can be adapted to a wide variety of arrangements for optimum utilization of the
available J1oor space.
• 'T'he enclosed space between the subfloor and the access floor provides space for:
- Accommodating spare cabling for present and future office technologies.
······Other occupant needs (e.g., heating, air conditioning, power).
The disadvantages of access J1oor systems are that they:
• Act as a soundboard.
• Have a high initial cost.
• May require that tiles with access holes be replaced when furniture is moved.
• May disrupt or be hazardous to office personnel when panels are removed.
• May be susceptible to haphazard cable placement.
• May be easily accessed by untrained and unqualified personnel.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Ceiling Distribution Systems
Overview
Ceiling distribution systems use the interstitial space between the structural ceiling
(e.g., physically part of the roof or floor above) and an accessible ceiling grid suspended
below the structural ceiling.
Several methods of using ceiling distribution to service work area locations are explained in
the following sections.
Acceptable Methods of Distribution
The methods of ceiling cable distribution described in this section are generally acceptable
ifthe:
• Ceiling is adequate and suitable.
• Ceiling space is available for cabling pathways.
• Ceiling access is controlled by the building owner.
• Code requirements for design, installation, and pathways are met.
• Building owners are aware of their responsibility for any damage, injury, or inconvenience
to occupants that may result from technicians working in the ceiling.
• Areas used for cabling pathways are fully accessible from the floor below (e.g., not
obstructed by fixed ceiling tiles, drywall, or plaster).
• Ceiling tiles are removable.
General Design Guidelines
The area above a suspended ceiling should be carefully planned to allow room for the
different utilities and telecommunications services it contains.
The ICT distribution designer should coordinate designs with all other discipline engineers
during design phases. Coordination between the various trades that use the ceiling space is
essential during shop drawing preparation and throughout the project.
Seismic requirements need to be incorporated into the design as they may require a greatly
increased support structure for both telecommunications pathways and other items in the
ceiling space.
Some facilities (e.g., health care) may have strict requirements regarding access to areas
above suspended ceilings. This should be taken into account during the planning and design
stages of any project.
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
Determining Adequate Ceiling Space
To determine how much ceiling space is adequate, the IC'T' distribution designer should:
• Consider the size and depth of the:
-- Structural beams and girders.
-Column caps.
- Mechanical services.
• Allow for a minimum of:
-- ::::::77 mm (3 in) of clear vertical space above conduits and cables.
- ::::::305 mm ( 12 in) of clear vertical space above the tray or raceway for overhead ceiling
cable tray or raceway systems.
When designing the layout of horizontal pathways in ceiling spaces, the ICT distribution
designer should ensure that other building components (e.g., luminaires, structural supports,
air ducts, and associated facility system controls) do not restrict access to cable trays or
raceways.
Selection of Ceiling Panels
The selection ofthe ceiling panel type should be coordinated with Table 5.16.
Table 5.16
Guidelines for recommending ceiling panels
Usc a Ceiling Panel That Is ...
Fora ...
Readily removable
Lay-in type panel on either a:
• Single support channel or
• Double support channel.
NOTES: Securely install and brace support
channels to prevent both vertical and
horizontal movement.
Use panels built from stable materials
to reduce panel damage from periodic
handling.
Lock-in type panel that requires a conduit
system.
Not readily removable
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
General Design Guidelines, continued
Restrictions on Ceiling Cabling
Cabling within ceiling space used as a plenum for environmental air shall comply with
applicable codes and regulations.
Ceiling Zones Method
In the ceiling zones method of ceiling distribution, the usable floor area should be divided
into zones of;::-;:;23.2 m 2 (250 ftl) to ;::::;92.9 m 2 (1000 ft 2) each.
How a zone is divided depends on the zone's purpose. For CPs, zones should preferably be
divided by building columns. Thedesign of BAS zones depends on the number of BAS,
coverage areas per cable, and other device-related factors.
NOTE: When CPs and CPs/TPs occupy the same zone box, the ICT distribution designer
should carefully consider the usable area for the voice and data usage calculations
and the total area f(w the BAS system calculation.
Pathways to each zone may be provided using cable trays within the ceiling area or enclosed
conduits or raceways. The raceways, conduits, or cable trays should extend from the
telecommunications spaces (e.g., ERs, TRs) to the midpoint of the zone. From that point, the
pathway should extend to the top of the utility columns or wall conduit.
NO'T'E: Appropriate codes, standards, regulations, and AHJ rulings should be consulted for
compliance with tlame spread and smoke index properties of cables used in cabling
pathway systems.
© 2020 BICSI®
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
Figure 5.30 shows a typical zoned ceiling distribution system (plan view).
Figure 5.30
Typical zoned ceiling (plan view)
r
I
'
E-
_J
--,
Junction box
r
E
r
~
L
-;:::::
-
Core
T
l_
r--3
r
_J
-'
c-~
-,
-,
L
E-
'
-,
78 mm (3 trade
size) conduit
TR~
.,g m (30 ft)
Utility column
27 mm (1 trade
size) conduit
\ ··j·t~J
.__...
/TR
.....::::::
\
··~
-':
L
53mm--r 2 trade size)
conduit
.......--i t:'\ r
if;
1:
-,
-,
_J
-'
---3
_J
TR = Telecommunications room
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
General Design Guidelines, continued
Figure 5.31 shows a typical conduit-based ceiling zone (elevation view).
Figure 5.31
Conduit-based ceiling zone (elevation view)
4
<I
4
<I
4
4
4
<I
Conduit
<I
4
4
J
4
4
4
,g m (30 ft)
maximum
4
<I
4
~Ceiling
<I
Utility~
column
4
II
II
~
~
tile
designated as
access tile to
zone conduit
4
<I
21 mm (3/4 trade size) conduit
1
4
(27
1 trade
~ conduit
mm size) ~
4
27 mm
(1 trade size)
conduit
<I
0
\ _ r:<101.6 mm (4 in)
x r:<101.6 mm (4 in)
telecommunications
outlet box
<I
4
4
<I
"'101.6 mm (4 in) x "'101.6 mm (4 in)
telecommunications outlet box
4
4
<I
4
4
<I
4
<I
"'
4
4
<I
<I
4
4
4
TR = Telecommunications room
© 2020 BICSI®
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
Pathway and Cable Support
Every ceiling distribution system shall provide proper support for cables from the
telecommunications space to the work areas served.
Ceiling conduits, raceways, cable trays, and cabling shall be suspended from or attached to
the structural ceiling or walls with hardware or other installation aids specifically designed to
support their weight.
The pathways shall:
• Have adequate support to withstand cable pulling.
• Be installed with at least -::::;77 mm (3 in) of clear vertical space above the ceiling tiles and
support channels (T-bars) to ensure accessibility.
• Specify that non-continuous supports are installed at intervals not exceeding
:::::1.52 m ( 5 ft) that will minimize cable sag while keeping cables a minimum of
:::::77 mm (3 in) above ceiling grid.
Horizontal pathways or cables shall not rest directly on or be supported by:
• Ceiling panels.
• Support channels (T-bars).
• Ceiling support wires.
• Other components of the suspended ceiling.
It is important to provide sufficient space between the suspended ceiling structure and the
telecommunications pathways and cables to install, maneuver, and store ceiling tiles during
service. When sufficient space is available above the pathway, up to :::::]52 mm (6 in) should
be provided between the suspended ceiling and the cabling pathways.
Where building codes permit telecommunications cables to be placed in suspended ceiling
spaces without conduit, ceiling zone distribution pathways may consist of:
• Cable trays.
• Open-top cable supports (e.g., J-hooks ).
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Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
NOTE: J-hooks should be located ;o.:;J.52 m (5 ft) apart at the maximum to adequately support
and distribute the cable's weight. The manufacturer's specifications for cable loading
should be followed (see Figure 5.32).
Figure 5.32
Rules of installation for discrete cable support facilities
@
@
:::<1.2-1.52 m (4-5ft)
Maximum :::<0.3 m (1ft)
@
@
Cable support devices that have narrow surface areas to support the cable lying horizontally
inside or on top may have a detrimental effect on the transmission performance of higher
performance cabling systems.
If possible, a wider surface area should be chosen to support the cable as a precaution against
potential problems. Another precaution would be to reduce the distance between the support
devices.
Suspended cables should be installed with at least ;o.:;77 mm (3 in) of clear vertical space above
the ceiling tiles and support channels (T-bars).
For large quantities of cables (50 or more) that converge at the ER, TR, and other areas,
provide cable trays or other special supports that are specifically designed to support the
required cable weight and volume.
Termination Space
The ICT distribution designer should allow maximum space in the ER or TR for the
horizontal cable terminations. Consult applicable codes, standards, regulations, and AHJ
rulings for appropriate use of spare cables.
NOTE: For details on wall and rack space for cross-connects, see
Chapter 3: Telecommunications Spaces.
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Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
General Design Guidelines, continued
Connecting Hardware in Ceiling Space
Connecting hardware shall be mounted in locations that are readily accessible. Mounting of
certain types ofhardware (e.g., CP) in a suspended ceiling space, while not recommended,
may be acceptable provided that the:
• Space is accessible.
• Building fixtures, equipment, or heavy furniture
(e.g., file cabinets weighing ::::45.4 kg [100 lb] or more) does not compromise access.
• Access does not disturb building occupants.
• Hardware is protected from physical abuse and foreign substances.
• Installation of connecting hardware is allowed by applicable codes, standards, regulations,
and AHJ rulings.
IMPORTANT: Telecommunications equipment should not be placed in the ceiling space.
Overhead Ceiling Enclosed Raceway Method
Above suspended ceilings, place metal-covered wireway system within the ceiling space to
distribute cables.
Install:
• Larger raceways to bring feeders into an area.
• Smaller, lateral (distribution) raceways to branch off from the feeder and provide services to
the usable floor space.
Feed work area locations with either flexible conduit or exposed cable (if codes allow).
Extend the conduit or exposed cables from distribution raceways to:
• Utility columns.
• Partitioned walls.
• Other distribution pathways.
NOTE: All applicable codes, standards, regulations, and AHJ rulings should be consulted for
compliance with the use of flexible conduit as a cabling pathway system.
TDMM, 14th edition
5-100
© 2020 BICSI®
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
Overhead Ceiling Raceways and fittings
Figure 5.33 shows raceways and fittings for a typical overhead ceiling raceway system.
Figure 5.33
Raceways and fittings
Consolidation
point on
lateral
Lateral
raceway
in hanger
suspended by
threaded rod
Tap-off
from lateral
raceway
Take-off fitting
between lateral
and header
raceways
Utility Columns
A utility column is a post used by a ceiling distribution system. Utility columns:
• Extend from the suspended ceiling support channel to the floor.
• Conceal and protect telecommunications cabling from the ceiling to the desks.
• May provide electrical outlets for work area equipment.
Utility columns that are used for both telecommunications and power distribution shall be
equipped with a baJTier and shall comply with applicable codes. When a metallic barrier is
used, it shall be bonded to ground.
Depending on their design and the care with which they are installed, utility columns may be
subject to slight shifts during and after placement. These shifts can cause a support channel to
become warped, marred, or bent. Excessive bending of support channels may cause a collapse
of ceiling panels.
© 2020 BICSI®
5-101
TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
When plans show ceiling cables concealed behind walls or partitions, the concealment
reqwres:
• An unimpeded vertical pathway.
• A pull cord.
The space permits the cable to pass from the telecommunications outlet box to the top of
the wall.
NOTE: For walls or partitions with snap-in panels or covers, specify a clear pathway.
Speci(y securing utility columns to the main ceiling support channels. The main ceiling
support channels shall be rigidly installed and braced to prevent both vertical and horizontal
movement.
NOTE: Utility columns may be attached to the transverse (cross) rails only if these rails are
securely anchored to the main ceiling support channel.
TDMM, 14th edition
5-102
© 2020 BICSI®
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
Several utility columns and their attachments to the ceiling or ceiling fixtures are shown in
Figure 5.34.
Figure 5.34
Attaching various utility columns
~Telecommunications
/
cable
~Hanger
clamp
Suspended _ /
T-bar ceiling
Utility~
column
Type
A
Type
B
Type
C
Type
D
Type
E
Type
F
~
t
/
Modular furniture
adapter
Can be fitted with an
additional snap-on
component
,54 mm
(2.13 in)
1._..1
bJ!
"'54 mm
(2.13 in)
"'70 mm
(2.75 in)
""70 mm
(2. 75 in)
1~1
I~
[][] t
"'36 rnrn
(1.17 in)
"'50 mrn
(2 in)
I_,.I
[rlT DT
"'73 mm
(2.87 in)
::::::50 mm
(2 in)
N57 rnrn
(2.24 in)
1.._..1
t
,57 mm
(2.24 in)
NOTE: Utility columns project through the suspended ceiling and provide access to
the overhead cabling system. Standard columns accommodate ::::;J m ( l 0 ft),
::::;3.7 m (12ft), and ::::;4.6 m (15ft) ceiling heights and mount rigidly between the
ceiling support channel grid and carpeted or tiled floor.
Side covers may be removable for placing of telecommunications cabling.
Telecommunications outlets/connectors are typically located on the sides of the column at
desk height or bottom. Utility columns shall be listed.
Utility columns that attach directly to modular furniture or partitions are also available.
Because these types of columns match the furniture construction, they blend into the
office environment, are well supported, and offer increased flexibility because of their
ability to conceal and support horizontal cabling routed directly to cable troughs and
telecommunications outlets/connectors mounted in the modular furniture.
© 2020 BICSI®
TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
General Design Guidelines, continued
Advantages and Disadvantages
The advantages of ceiling distribution systems are that:
• The cost of setting up the system can be delayed until the floor space is rented.
• They provide:
- Good concealment.
- A flexible way to distribute cables to desk locations.
- Adequate space to place cables throughout the floor area.
• Cable lengths are kept to a minimum.
• Cable can be:
- Dedicated to serve a specific floor area.
-Reused.
• Telecommunications outlets/connectors can be relocated short distances without replacing
cables.
• Additional cable can be placed easily with minimum inconvenience to tenants.
• The initially required cable can be quickly and easily placed to approximate locations before
the ceiling is installed.
The disadvantages of ceiling distribution systems are that they:
• Are completely inaccessible over:
-- Plaster ceilings.
- Spline ceilings.
- Sealed air plenum.
• May create electrical hazards or pick up noise interference from lighting fixtures and power
circuits.
• Can be put out of service accidentally by technicians working on other systems in the
ceiling.
• May require utility columns, which may affect the aesthetics of the office.
• May require damaged ceiling tile replacement, which may cause a patchwork effect in the
ceiling.
• Create hazards or interruptions for office workers when technicians work on ladders during
office hours.
ln addition, its advantages are limited, to some degree, by the type of modular furniture
used. Ceiling systems may also damage ceilings or other office fixtures and furnishings.
Specifically, ceiling systems may cause damage to:
• Ceiling tiles and rails because of pole movement or improper cable support.
• Furniture, which may be soiled or damaged by falling debris or by technicians during
service.
TDMM, 14th edition
5-104
© 2020 BICSJ:®
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Cable Tray Systems
Cable tray systems are commonly used as distribution systems for cabling within a building.
They are often preferable to rigid conduit and raceway systems because of their greater
accessibility and ability to accommodate change. Cable trays are a cable support system and
not considered a raceway.
Cable tray systems:
• Are rigid, prefabricated support structures that support telecommunications cables.
• Shall be installed to meet applicable building codes.
Although such practice may be allowed by some building codes, ICT distribution designers
are strongly advised not to use shared cable trays to distribute telecommunications
and electrical power cables. lf trays or wireways are shared, the electrical power and
telecommunications cables shall be separated by a nonconductive or grounded metallic
barrier.
When a tray is used in the ceiling area, conduit should be provided from the tray to the
telecommunications outlets/connectors or zones, except in cases where loose cables are
permitted by and meet the applicable codes.
NOTE: The inside of a cable tray shall be free ofburrs, sharp edges, or projections that can
damage cable insulation. For penetration of rated walls using cable trays, see
Chapter 7: Firestop Systems.
Types of Cable Trays
The basic types of cable trays are described in Table 5.17.
Table 5.17
Common types of cable trays
© 2020 BICSI®
Type of Cable Tray
Structural Description
Ladder
Two side rails connected by individual transverse rungs
or stringers
Ventilated trough
A ventilated bottom with side rails
Ventilated channel
Channel section with a one-piece bottom no more than
:::::152.4 mm (6 in) wide
Solid bottom
Solid bottom with longitudinal side rails
Spine
Open tray having a central rigid spine with cable
support ribs along the length at 90 degree angles
Basket tray
A welded steel wire mesh
5-105
TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Cable Tray Systems, continued
Cable Tray Fittings and Accessories
The fittings used for changing the direction or size of a cable tray include:
• Elbows.
• Reducers.
• Crossovers.
• Tees.
The accessories used with cable trays include:
• Covers.
• Hold-down devices.
• Dropouts.
• Conduit adapters.
• Dividers.
Cable Tray Dimensions
The dimensions in rl~1ble 5.18 illustrate a variety of tray sizes to suit most applications
for horizontal cable distribution. Other sizes and designs are available to accommodate
special needs and installations. The lengths, widths, and depths shown in Table 5.18 are not
necessarily precise measurements but are intended for general information purposes only.
Cable tray manufacturers should be consulted for a comprehensive listing of standard models.
NOTE: Consult cable tray manufacturers for tolerances of specific models.
TDMM, 14th edition
5-106
© 2020 BICSI®
Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Cable Tray Systems, continued
Table 5.18
Common cable tray dimensions
Ventilated
Lengths
Widths
(Inside)
""3.7 111 (12ft)
~7 .3 m (24 ft)
:::.:3.7 m (12ft)
~7 .3 111 (24ft)
""152.4ml11 (6 in)
(12 in)
~457 111111 (18 in)
~610 111111 (24 in)
~762 mm (30 in)
~914 111m (36 in)
~152.4 111111
~305 111111
Ventilated
Channel
Trough
Ladder
~305 111111
(6
(12
~45 7 111111 ( 18
~610 mm (24
~762 111111 (30
~914 111111 (36
~3.7 111
q,3
in)
in)
in)
in)
in)
in)
111
(12ft)
(24ft)
Solid
Bottom
';c:3.7 m (12ft)
~7.3 111 (24ft)
::o:_77 111111 (3 in)
""152.4 mm (6 in)
~101.6 mm (4 in) ~305 111111 (12 in)
~152.4 111111 (6 in) ~457 mm (18 in)
~610 mm (24 in)
~762 111111 (30 in)
';c:914 mm (36 in)
Basket
Tray
""3m(l0ft)
~51 111m
~10 1.6
(2 in)
mm ( 4 in)
""152.4 mm (6 in)
""203 mm (8 in)
cc::;305 111111 ( 12 in)
~406 111111 ( 16 in)
~457 mm (18 in)
cc::;508 111111 (20 in)
~61 0 mm (24 in)
NOTE: The side rail outside depths (height) can be as much as ~32 mm ( 1.25 in) more than the inside loading depth
for ladder, ventilated trough, and solid bottom cable trays.
~n
~::77 111111
~32 111111
~101.6 111111
~101.6 111111
;:::;45
~305 111111 (12 in)
:::.:;610 111111 (24 in)
::::o9J4 mm (36 in)
:::.:;305 mm (12 in)
;:::;61 0 111111 (24 in)
;::;914 111111 (36 in)
:::::305 mm (12 in)
:::.:;6]0 111111 (24 in)
:::.:;914mm (36 in)
Degrees
of arc
30°
45°
600
90°
300
45°
600
900
300
45°
600
900
Transverse
element
spacing
:::.:;] 01.6 111111 ( 4 in)
Depths
111111 (3 in)
(4 in)
~127 111111 (5 in)
""152.4 111111 (6 in)
Rung
spacing
""152.4111!11 (6 in)
~229 111111 (9 in)
""305 mm (12 in)
::::o457 111111 ( 18 in)
Radii
""305
111m (12 in)
111111 (24 in)
""914 111111 (36 in)
~610
© 2020 BICSI®
(3 in)
(4 in)
~127 111111 (5 in)
~152.4 111111 (6 in)
111111
5-107
(1.25 in) ~n mm (3 in)
(1.75 in) "'101.6 mm (4 in)
;.:o:J27mm (5 in)
""152.4 111111 (6 in)
;:::;38 111111 ( 1.5 in)
::::;51 mm (2 in)
;:::;J01.6mm (4 in)
;.:o:J52.4 111111 (6 in)
TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Cable Tray Systems, continued
Cable Tray Capacity
The working load capacity of a cable tray system is determined by the:
• Static load capacity of the tray.
• Length of the support spans.
NOTE: Total cable weight per meter (equivalent in feet) is rarely the limiting factor in
determining the allowable cable tray fills for telecommunications cables. For
horizontal cables, the allowable fill volume is usually obtained before the allowable
weight is reached.
For cable trays penetrating fire- or smoke-rated partitions, the firestop listing may limit
allowable cable tray fi 11.
Supporting Cable Trays
Cable trays should be supported by installing:
• Cantilever brackets.
• Trapeze supports.
• Individual rod suspension brackets.
Supports shall be spaced according to the cable load and span as specified for the cable tray's
type and class by the manufacturer and applicable codes. Supports should be placed so that
connections between sections of the cable tray are between the support point and the quarter
section ofthe span.
Trays and wireways are usually supported on ::::;J.52 m (5 ft) centers unless they are designed
for greater spans. A support shall also be placed within ::::;0.6 m (2 ft) on each side of any
connection to a fitting.
WARNING: Cable trays should never be used as walkways, ladders, or support for
personnel. Cable trays shall only be used as mechanical support for cables.
Bonding and Grounding Cable Trays
All metallic cable trays shall be grounded and all sections bonded in accordance with listing
requirements for the particular type of system.
All cable trays and bonding conductors should be clearly marked in accordance with
manufacturer's instructions, applicable codes, standards, and regulations.
NOTE: See Chapter 8: Bonding and Grounding (Earthing).
TDMM, 14th edition
5-108
© 2020 BICSI®
Section :2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Conduit and Raceway Distribution Design
Ceiling Home-Run Method Using Conduit
In a home-run ceiling conduit system, a continuous run of conduit is placed from the
telecommunications outlet boxes to the ER or TR.
Based on a maximum cable 00 of 6.3 mm (0.25 in), the following guidelines apply. For
conduits that serve:
• One or two boxes, an 10 of 25.4 mm ( l in) or greater is recommended.
• Three boxes, an 10 of 32 mm ( 1.25 in) or greater is recommended.
NOTE: Although home-run conduits may serve up to three telecommunications outlet
boxes, each horizontal cable run may serve only a single telecommunications
outlet/connector (e.g., no looping or bridge taps). The increase in 4-pair cable
diameters has resulted in an increased recommended minimum conduit size to be
no less than 25.4 mm ( 1 in) ID.
Zone Conduit Size
The following guidelines on zone conduit size are based on the conduit capacity
recommendations (see Table 5.5) and on the assumption of three cables per individual work
area and one individual work area per :.::;9.3 m 2 (100 ft 2 ).
When running up to two 4-pair cables and two optical fibers to each work area, at
least one ;::;53 mm (2 trade size) conduit should be used for each zone ranging from
:.::;23.2 m 2 (250 ft 2 ) to ;::;55. 7 m 2 ( 600 ft2 ). This is based on :.::;5.6 m 2 ( 60 ff) to ;:.::9.3 m 2 ( 100 ft 2 )
work areas and the diameter of the cable no larger than 6.3 mm (0.25 in). For larger zones
ranging from :.::;55.7 m 2 (600 ftl) to :.::;84m 2 (904 ft 2), an :.::;63 mm (2-1/2 trade size) conduit
should be used.
NOTE: For conduits that contain more than one cable type, the size should be determined
based on the largest diameter cable and the total number of cables it is expected
to hold.
© 2020 BICSI®
5-109
TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Other Horizontal
Overview
Other types of pathways include:
• Messenger or support strand.
• Perimeter (i.e., surface) raceway systems.
• Furniture pathways
• Overfloor ducts.
• Molding raceways.
• Poke-thru.
Perimeter raceways, molding raceways, and overfloor ducts are limited to use only in dry
locations.
NOTE: To determine the size of these pathways, the manufacturer's recommendations should
be followed.
These pathways shall not have any sharp edges-bushings should be provided to cover any
sharp edges. These pathways should not be routed through gaps in the floor structure, the
ceiling structure, or a curtain wall.
Messenger or Support Strand
Messenger or support strand is similar to what is used for outside plant to carry the weight of
telecommunications cables that are either lashed or ring supported. This support method is
used in ceiling voids, crawl spaces, tunnels, and areas with unfinished, exposed, or structural
ceilings.
NOTE: Messenger or suppoti strand shall be bonded and grounded in accordance with
Chapter 8: Bonding and Grounding (Earthing).
Perimeter Pathways
Perimeter pathways are often used to serve work areas where telecommunications devices
can be reached from walls or partitions.
NOTE: Perimeter pathways and the telecommunications cabling contained within those
pathways shall meet or exceed applicable codes, standards, regulations, and AHJ
rulings.
Examples of perimeter pathways include:
• Surface raceways that typically mount directly on walls and other surfaces.
• Recessed raceways that may be integrated into the walls and other surfaces.
• Molding raceways that are surface mounted and may have a cove molding appearance.
• Multi-channel raceways that are suitable for supporting ditTerent systems
(e.g., electrical power, telecommunications, other circuits).
TDMM, 14th edition
5-110
© 2020 BICSJ:®
Chapter 5: Horizontal Distribution Systems
Section 2: Horizontal Pathways
Perimeter Raceways
Perimeter raceways are available in:
• Plastic, metal, or wood.
• Recessed or surface-mounted designs.
• Baseboard or chair rail heights.
In most designs:
• The front panel is removable.
• Telecommunications outlets/connectors may be placed at any point along the run and may
be moved or added after initial installation.
In a perimeter raceway, electrical power and telecommunications services shall be run in
separate compartments and shall comply with applicable codes. When a metallic barrier is
provided, it shall be bonded to ground.
The assignment of raceway compatiments to either telecommunications or electrical power
circuits should be consistent throughout the premises.
Perimeter raceway systems are similar in design to the raceway systems provided with open
office (also called modular) furniture systems. Much of the distribution methodology used for
perimeter raceway systems also may be applied to open office furniture systems. When these
systems are used to distribute and conceal horizontal cabling (as with movable partitions), the
pathways shall be accessible via a snap-in panel or removable cover.
In cases where the security oftelecommunications cabling is a consideration, perimeter
raceways are available in locking versions.
The practical capacity for telecommunications cabling in perimeter raceways is between
20 percent and 40 percent fill, depending on the cable bending radius. The pathway size
shall be obtained by dividing the sum ofthe cross-sectional area of all cables by the percent
(expressed as a decimal fraction) of fill.
Perimeter raceways should be used primarily for small floor areas where the majority of
telecommunications service will be along the walls as shown in Figure 5.35.
NOTE: Effective cross-sectional area may be affected by factors such as the minimum cable
bending radii through tlttings and intrusion of telecommunications outlets/connectors
into the raceways. Consult raceway manufacturers for information on effective
cross-sectional area in these instances. Perimeter raceways may later be filled up to
60 percent fill factor if required.
© 2020 BICSI®
5-111
TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Perimeter Raceways, continued
Figure 5.35
Perimeter raceway
-,;:;===~~ivided
caeeway io wall-mounted at deok height
with data telecommunications and power outlet
spaced as needed
""---
Combination duplex
receptacle and telecommunications
outlet/connector cover
-··u
I
Perimeter raceway system
provides both premises and power
wiring at baseboard level
~
Building perimeter distribution system provides
convenience outlets (telecommunications
and power) in larger office areas
7
Divided raceway runs in - - . _
~
smaller offices are either
-----...::::;
back-connected through partitions
or built into modular furniture
TDMM, 14th edition
5-112
© 2020 BICSI®
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Molding Raceways
The types of molding raceways include large:
• Picture molding for use in rooms.
• Wood or eaves trough metal moldings for use in hallways.
• Baseboard and crown molding.
Place sleeves in the walls to connect room and hall moldings. Use conduits to connect
hallway moldings to work area locations.
Generally, this type of installation is outdated. lt is acceptable in some buildings
(e.g., apartments, hotels) ifthe moldings are accessible from the work area as shown in
Figure 5.36.
Figure 5.36
Molding raceway
'.
'•
·..
'•
...
.
.~
•,
.
.. .
·.
Conduit nipple
reamed ends
© 2020 BICSI®
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TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Open Office Modular Furniture and Partition Pathways
Where modular furniture and partitions are used to conceal horizontal and work area cabling,
a panel or cover shall be provided to ensure that the cabling remains secure from office
personnel. Utility columns that span from the floor to the ceiling in a work area arc one
example of such a cabling pathway. If an accessible space or pathway inside a building's
interior or exterior wall is of sufficient size, it also may be used to conceal cabling. Surface
raceway systems may be installed on modular furniture systems. The AHJ requirements
should be considered when selecting the containment system and components.
Furniture manufacturers typically provide planning information and assistance to clients
to make sure that adequate pathway capacity is available for the intended application. The
following information should be shared among the manufacturer, customer, ICT distribution
designer, and installer:
• The number, type, and location of cable connections required in each work area
• The diameter and minimum bend radius of each cable type
• The strategy of building pathways connection to furniture pathways, including the number,
placement, and cross-sectional area of the required interfaces
• Furniture pathway cross sections and cable capacities
• 'fhc number of work areas in each furniture cluster
Additionally, modular furniture systems telecommunications distribution planning and design
should consider the following guidelines:
• Coordinate all the supporting functions, including:
Cabling pathways for both telecommunications and electrical power.
--Telecommunications outlet/connectors for telecommunications devices.
- Connection of furniture pathways to horizontal building pathways.
• Consult manufacturer information about:
- Intended applications of modular furniture systems.
- Intemal pathway capacity and bend radius.
- Separation of electrical power and telecommunications cabling.
-Any special tooling requirements.
• The cross-sectional area of the straight section of a furniture pathway for
telecommunications cabling shall be at least o.::::970 mm 2 ( 1.50 in 2). The minimum size
pathway shall not force the cable bend radius to be Jess than o.::::25.4 mm (I in) under
conditions of maximum cable fill.
NOTE: The bend radius is dependent on the diameter of the horizontal cable, and it could
reach o.::::33 mm (1.3 in).
• Furniture and horizontal initial pathway capacity should not exceed 40 percent of the
pathway cross section. A maximum of 60 percent pathway fill is allowed to accommodate
unplanned additions after initial installation. This fill ratio range may be used as an estimate
and does not account for corners and other factors.
TDMM, 14th edition
5-114
© 2020 BICSI®
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Open Office Modular Furniture and Partition Pathways, continued
NOTE: Actual cable mockups are the preferred method to determine cabling pathway
capacity.
• When telecommunications cabling pathways run parallel to electrical pathways, the
recommendation is a minimum of:::::51 mm (2 in) separation. Requirements found in
applicable cabling standards or codes shall be met. In multi-channel metallic pathways,
metallic dividers between channels shall be bonded to ground (earth).
NOTE: See Chapter 2: Electromagnetic Compatibility for cable separation guidelines.
• For safety purposes and to meet codes, keep power cables separated from
telecommunications cables by a physical barrier.
• Where users need to frequently move desks or tables, it may be preferable to locate
telecommunications outlets/connectors in furniture panels, walls, or other fixed locations
rather than on desks or tables.
• Access considerations for the physically challenged may affect telecommunications
outlet/ connector mounting locations in some instances. National, regional, local, or
building regulations may apply.
• Safety, reliability, and aesthetic concerns also need to be considered.
• Pathways used to interconnect the furniture with building horizontal pathways shall be
provided with a cross-sectional area at least equal to the relevant horizontal pathways
cross-sectional area. Care shall be exercised so that these pathways do not trap access
covers or otherwise block access to building junction boxes or other pathways.
Generally, furniture pathways at any level above the floor should be fed from either the floor
or ceiling. Thus, vertical pathways should be provided with a cross-sectional area at least
equal to the horizontal pathway cross-sectional area. This specification is based on a work
area cluster serving four persons with three connections each.
Because of complex raceway shapes and obstructions, cable installation in furniture pathways
by fish-and-pull techniques may cause lower capacity compared with when cables are placed
into the pathways. Fish-and-pull installation should not be used except when required by
furniture pathway characteristics such as a raceway with a non-removable cover.
Certain types of cables may require larger bend radii than conventional cables. Hybrid cables
may be unsheathed into component cables at the entry point to fumiture, if necessary, to
make the bend radius manageable. The minimum bending radii shall be obtained by an
ICT distribution designer from the cable manufacturer.
The usable cross-section of some furniture pathways is reduced by the bend radius
requirements of the cable. Information on the usable cross-section or cable capacity at
pathway intersections for representative cables shall be provided by furniture manufacturers.
© 2020 BICSI®
5-115
TDMM, 14th edition
Section 2: Horizontal Pathways
Chapter 5: Horizontal Distribution Systems
Poke-Thru
Because of significant drawbacks with poke-thru distribution, it is not generally
recommended as a horizontal cabling solution. However, there are situations where poke-thru
is the only available method.
Poke-thru distribution is typically implemented by:
• Installing cable from the telecommunications space.
• Running it beneath the same floor where the telecommunications space is located
(i.e., within the ceiling of the floor below) to a point below where service is desired on
the same floor.
• Penetrating the floor to allow the cable to be attached to a telecommunications service
fitting.
Poke through devices are:
• Designed to maintain the fire rating of the penetrated floor.
• Used primarily to provide power and telecommunications cabling to open space
environments.
Compliance with all applicable codes, standards, regulations, and AHJ rulings shall be met.
WARNING: Poke-thru coring may aiiect the structural integrity of the floor. A structural
engineer should be consulted in the early design stages regarding poke-thru
quantities, diameters, spacing, and locations.
TDMM, 14th edition
5-116
© 2020 IHCSI®
Section 3: ADA Requirements
Chapter 5: Horizontal Distribution Systems
Americans with Disabilities Act (ADA) Requirements
Overview
Disabled access guidelines may not apply to all countries. However, ADA and BICSI best
practices are provided for the ICT distribution designer's consideration. The U.S.
Department ofJustice's 2010 ADA Standardsfor Accessible Design, which took effect
September 15, 2010, may be helpful. Consult the ADA for specific information.
In the United States, Title III of the ADA is of primary concern to design consultants in
the building industry because it defines public accommodations and commercial facilities,
including:
• Medical care facilities.
• Correctional and detention facilities.
• Establishments serving food or drink.
• Sales or rental establishments.
• Service establishments.
• Stations used for specified public transportation.
• Social service center establishments.
• Theaters.
• Stadiums, arenas, and grandstands.
• Residence halls or dormitories (apartments and townhouses are exempt).
• Places of:
-Transient (short-term) lodging.
- Exhibition or entertainment.
- Public gathering.
- Public display or collection.
-- Education.
-Exercise or recreation.
A facility is considered a place of public accommodation if it:
• Is operated by a private entity.
• Conducts operations that afTect commerce.
• Meets the guidelines listed in Title III of the ADA.
A commercial facility is one whose operation affects commerce even though that is not its
main function.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 5: Horizontal Distribution Systems
Section 3: ADA Requirements
Americans with Disabilities Act (ADA) Existing facilities Rule
The U.S. Department of Justice revised the original language in the proposed rule that stated
"any public accommodation or other private entity responsible for design and construction"
shall ensure that facilities conform to the law.
The revised rule states that "discrimination .. .includes a failure to design and construct
facilities." This interpretation emphasizes the responsibilities of developers, contractors,
consultants, and other members of the building industry.
Title Ill of the ADA affects three sets of activities pertinent to existing facilities:
• Readily achievable removal of barriers
• Alterations
• New construction
Readily Achievable Removal of Barriers
Readily achievable removal of barriers means removal of architectural and communications
barriers to the disabled that can be accomplished easily and carried out without much
difficulty or expense.
Examples include:
• Lowering or adjusting public telephone enclosures.
• Adding a TTY.
• Ensuring that auxiliary aids (e.g., hearing aid-compatible handsets) are installed to public
telephones.
The ADA considers the size and nature of the removal project by applying conditions to
determine what kinds of barrier removal arc readily achievable. As of January 26, 1993,
places of accommodation within the United States shall comply with all ADA requirements.
Alterations
Altered areas in all buildings shall be readily accessible and usable to the maximum extent
possible. When alterations arc made to a primary function area (e.g., lobby or work areas of
a bank), an accessible path of travel to the altered area, and to the restrooms, telephones, and
drinking fountains serving that area, shall be provided.
The extent of accessibility is limited only in that the costs are not disproportionate to the
overall cost of the original alteration. (The added accessibility costs are dispropmiionate if
they exceed 20 percent of the original alteration.)
New Construction
Any new building or facility shall adhere to the ADA construction requirements, and a
government building or facility shall adhere to the Architectural Barriers Act.
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Section 3: ADA Requirements
Chapter 5: Horizontal Distribution Systems
Public Telephones and Text Telephones
Because of developments within the FCC and the Telecommunications for the Deaf, Inc.,
the acronym for the text telephone mode has been changed from TDD to TTY.
One interior TTY shall be provided on each floor of a site with four or more public telephones
as long as one ofthe four telephones is located inside the facility and at each bank of four or
more public telephones.
Covered shopping malls and convention centers shall provide one interior TTY regardless of
the number of public telephones at the location.
Hospitals are required to provide TTY s on public telephones serving:
• Emergency rooms.
• Waiting rooms.
• Recovery rooms.
Transportation sites are required to provide TTY s on public telephones serving:
• An entrance to a bus facility.
• An entrance to a rail facility.
• A concourse in an airport within the security area.
• An airport baggage claim area.
Hotels shall provide a TTY or similar device at the front desk. In addition, four percent of the
first 100 rooms and approximately two percent of rooms in excess of 100 shall be accessible
to persons with hearing impairments.
The rooms shall contain:
• Visual notification devices.
• Volume control telephones.
• An accessible electrical outlet for a TTY.
A portable TTY is permitted if it is readily available for use with a nearby public telephone
that is equipped with all of these features:
• A shelf
• An electrical outlet
• A handset cord long enough to allow an acoustic coupler connection
In newly constructed or altered facilities where a bank of telephones in the interior of a
building consists of three or more public telephones, at least one public telephone in each
bank shall be equipped with:
• A shelf.
• An electrical outlet.
• A handset cord long enough to allow the handset to rest on the shelf. This ensures the
handset cord will allow the handset to rest in an acoustic coupler connection.
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TDMM, 14th edition
Section 3: ADA Requirements
Chapter 5: Horizontal Distribution Systems
Americans with Disabilities Act (ADA) Height Requirements
In the United States, the ADA language gives reach ranges for elements such as public
telephones in terms of highest operable mechanism. Drive-up public telephones and
communications system receptacles not normally intended for use by building occupants
are exempt from height requirements. Exemptions for communications receptacles serving a
dedicated use and operable parts intended only for use by service or maintenance personnel
apply.
Table 5.19 explains the ADA height requirements for adults.
Table 5.19
ADA height requirements
Side-Reach Telephones
Forward-Reach Telephones
The maximum high side reach allowed is
:::::1220 mm (48 in).
The maximum high forward reach allowed
is :::::1220 111111 (48 in).
If side reach occurs over an obstruction
:::::610 mm (24 in) wide and :::::864 111111 (34 in)
high, the maximum height allowed is
:::::1170 mm (46 in).
If forward reach occurs over an
obstruction :::::508 m111 to :::::635 111111
(20 in to 25 in), the maximum height
shall be::::: 1120 nun ( 44 in).
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© 2020 BICSI®
Section 3: ADA Requirements
Chapter 5: Horizontal Distribution Systems
Americans with Disabilities Act (ADA) Height Requirements, continued
Figure 5.37 illustrates the allowed dimensions for side-reach telephones.
Figure 5.37
Side-reach telephones
""254 mm
(10 in)
maximum
1-T
11
1"'1220 mm
:
(48 in)
"'1220 mm
(48 in)
I
I
I
I
I
"'254 mm
(10 in)
maximum
L--·-- - - - - - - - - _
l
I
I
I
I
_J
...,_"'762 mm_..
(30 in)
Clear floor space
""381 mm
(15 in)
High and low
Parallel approach
i
""864 mm
(34 in)
Side reach limits
""1170 mm
(46 in)
maximum
1
Maximum side reach over obstruction
NOTE: The minimum height for all electrical and communications systems receptacles on
walls (e.g., outlets, connectors) shall be ;:::;381 mm (15 in) AFF.
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Section 3: ADA Requirements
Chapter 5: Horizontal Distribution Systems
Americans with Disabilities Act (ADA) Height Requirements, continued
Figure 5.38 illustrates the allowed dimensions for forward-reach telephones.
Figure 5.38
Forward-reach telephones
:o:o1220 mm
..,...__ _ (48 in) ---1~
Credit card
reader
E-I-~-~-~-~-~-~-~-~-~-~-~----~t:o:o762 mm
(30 in)
1
I
I
:o:o1220 mm
( 48 in)
lr~
~~~~~~~:
~
-------------~~
r---:
I
:o:o1220 mm
(48 in)
-+
minimum
High forward reach limit
...---+-- -----------...-
Operator~
button
~~~
\
I
:
I
ll....lf--1--------- _i
t
""762 mm
(30 in)
__j_
y
z
1
::oe1220 mm
l.,.illll--- (48 in) ---+--
::oe1220 mm
(48 in) ---+--
...a---
Maximum forward reach over an obstruction
NOTES: X shall be< :::::635 mm (25 in); Z shall be> X. When X< :::::508 nun (20 in), then
Y shall be :::::1220 mm (48 in) maximum. When X is :::::508 to 635 nun (20-25 in),
then Y shall be :::::Jl20 mm (44 in) maximum.
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Section 3: ADA Requirements
Chapter 5: Horizontal Distribution Systems
Text Telephones
A generally available public telephone with a coin slot or credit card reader mounted
lower on the equipment would allow universal installation of telephones at a height of
:::::]220 mm (48 in) or less.
A public text telephone may be an integrated text telephone/public telephone unit or a
conventional potiable text telephone that is permanently affixed in (or adjacent to) the
telephone enclosure.
To be usable with a conventional public telephone, a text telephone that is not a single
integrated text telephone public telephone requires:
• An electrical outlet.
• An electrical power cord.
• A shelf with dimensions of:
:::::254 nun (10 in) wide.
-- :::::254 111111 ( l 0 in) deep.
-:::::152.4 mm (6 in) vertical clearance.
Movable or portable text telephones may be used to provide equivalent help. A text telephone
should be readily available so that a person using it may have easy and convenient access.
Pocket-type text telephones for personal use do not accommodate a wide range of users.
Such devices are not considered substantially equivalent to conventional text telephones.
Volume Control
In newly constructed or altered facilities, 25 percent of the public telephones shall be
equipped with volume controls.
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Chapter 5: Horizontal Distribution Systems
Section 3: ADA Requirements
Signs
lf a facility has a TTY, directional signs indicating the nearest TTY location shall be placed
adjacent to all banks of telephones that do not contain a TTY. Such signs shall include the
international symbol for TTY.
A sign also shall identify the TTY location with the international symbol for TTY as shown
on the left in Figure 5.39. Telephones required to have volume control shall be identified by
a sign showing a telephone handset with radiating sound waves as shown in Figure 5.39.
Figure 5.39
International teletypewriter/text telephone symbol and volume control telephone symbol
~
00000
DODO
00000
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© 2020 BICSI®
Section 3: ADA Requirements
Chapter 5: Horizontal Distribution Systems
Appendix: Disabled Access and the Americans with
Disabilities Act (ADA)
Americans with Disabilities Act (ADA): A Civil Rights law
The ADA is a civil rights law. This means that unless a state law or local building code adopts
the ADA requirements or unless the given code is certified by the U.S. Department of Justice,
state and local building inspectors will not enforce the law.
The law will be enforced (as are other civil rights laws) by action of an aggrieved party. The
ADA permits a person to file a lawsuit if that person has reasonable grounds for believing that
discrimination has occurred or is about to occur.
Additional Information
Additional information about ADA requirements can be found at the following websites:
• U.S. Department of Justice: www.ada.gov
• United States Access Board: www.access-board.gov
• Federal Communications Commission: www.fcc.gov
NOTE: Issues of the Federal Register are on file at many U.S. public libraries and may be
photocopied.
© 2020 BICSI®
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TDMM, 14th edition
Chapter 6
ICT Cables and
Connecting Hardware
Chapter 6 discusses balanced twisted-pair, coaxial, and
optical flber cabling, which may be divided into two
general environmental types-OSP and premises (also
known as ISP). Classification of cables by their flre
safety properties is included.
Chapter 6: ICT Cables and Connecting Hardware
Table of Contents
ICT Cables and Connecting Hardware . . . . . . . . . . . . . . . . . . . . . . . . . • 6-1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Environmental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Balanced Twisted-Pair Cables . . . . • • . . . . . . . . . . • . . . . . . . . . . . . . . • . 6-3
Classification of Cables by Their Transmission Performance . . . . . . . . . . . . . . . . . 6-3
Classification of Cables by Physical Makeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Four-Pair Cables and Multipair Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10
Effectiveness of Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
Four-Pair Cordage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
Selection of Solid versus Stranded Conductor Patch Cords . . . . . . . . . . . . . . . . . 6-13
Typical Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
Optical Fiber Cables . . . . . . . . . . .
~~
. . . . . . . . . . . . . . . . . . . " ....
~~
.. 6-14
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-17
Loose-Tube Optical Fiber Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
Tight-Buffered Optical Fiber Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-22
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
Optical Fiber Patch Cords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
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Chapter 6: ICT Cables and Connecting Hardware
Coaxial Cables . .....
~~
II!
................
II
•••
Ill
•
II
••
Ill
•
1!1
Ill
~~
••
~~
••••
6-24
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
Selection of Coaxial Cables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26
Classification of Cables By Fire Safety Properties . . . . . . . . . . . . . . . . . . . . . . . 6-27
Type CMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Type CMR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Type CMG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Type CM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Type CMX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Type CMUC Undercarpet Wires and Cables . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Type -LP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29
Types OFNP and OFCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29
Types OFNR and OFCR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29
Types OFNG and OFCG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29
Types OFN and OFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29
Balanced Twisted-Pair Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . • 6-33
Insulation Displacement Contact (IDC) Connectors-Overview . . . . . . . . . . . . . . 6-33
110-Style Insulation Displacement Contact (IDC) Connector . . . . . . . . . . . . . . . 6-33
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-33
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-35
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
66-Style Insulation Displacement Contact (IDC) Connector . . . . . . . . . . . . . . . . 6-36
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-37
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-38
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39
BIX-Style Insulation Displacement Contact (IDC) Connector . . . . . . . . . . . . . . . . 6-39
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-41
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-41
LSA-Style Insulation Displacement Contact (IDC) Connector . . . . . . . . . . . . . . . 6-41
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-42
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-43
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-43
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44
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© 2020 BICSI®
Chapter 6: ICT Cables and Connecting Hardware
Modular Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44
Modular Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-46
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-47
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-47
Modular Jack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-51
50-Position Miniature Ribbon Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-51
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-52
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . 6-53
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
Balanced Twisted-Pair Connecting Hardware ......•..•........•. 6-55
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-55
Balanced Twisted-Pair Outlets/Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-55
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-56
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Balanced Twisted-Pair Patch Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-59
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
Balanced Twisted-Pair Connecting Blocks •..........•••........ 6-61
66-Style Connecting Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-61
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
110-Style Wiring Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-64
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-64
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-65
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-65
© 2020 BICSI®
6-iii
TDMM, 14th edition
Chapter 6: ICT Cables and Connecting Hardware
BIX-Style Connecting Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-66
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-67
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-67
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-67
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-68
LSA-Style Connecting Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-68
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-70
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-70
Balanced Twisted-Pair Cable Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-70
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-71
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-72
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-72
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-72
Balanced Twisted-Pair Splices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-73
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-73
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-75
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-75
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-76
Optical fiber Connectors.
II
II
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II
II
II
•
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a
•
II
II
II
II
II
•
II
•
II
II
II
II
II
II
II
II
II
II
II
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•
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6-77
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-77
LC-Style Optical Fiber Plugs and Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-80
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-80
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-80
Advantages
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-81
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-81
SC-Style Optical Fiber Plugs and Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-81
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-81
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-82
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-82
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-82
ST-Style Optical Fiber Plugs and Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Other Styles of Optical Fiber Plugs and Adapters . . . . . . . . . . . . . . . . . . . . . . . . 6-83
TDMM, 14th edition
6-iv
© 2020 BICSI®
Chapter 6: ICT Cables and Connecting Hardware
Splices (Optical Fiber Connectors) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-85
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-85
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-86
Optical Fiber Pigtail Splicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-88
Optical fiber Connecting Hardware • . . • • . . . . . . . . . . . . . . . . . . . . . . 6-89
Telecommunications Outlets/Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Patch Panels and Enclosures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-89
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-91
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-91
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-91
Equipment Cords and Patch Cords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-92
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-92
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-92
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-93
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-93
Splices (Optical Fiber Connecting Hardware) . . . . . . . . . . . . . . . . . . . . . . . . . . 6-93
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-93
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-94
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-94
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-94
Coaxial Connectors
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Ill
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6-95
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-95
BNC-Style Coaxial Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-95
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-96
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-98
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-98
· Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-99
F-Style Coaxial Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-99
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-99
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-100
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-100
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-100
© 2020 BICSI®
TDMM, 14th edition
Chapter 6: ICT Cables and Connecting Hardware
N-Style Coaxial Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-101
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-101
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-101
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-102
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-102
Coaxial Connecting Hardware ............•.••••..••.••...••• 6-103
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-103
Coaxial Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-103
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-104
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-104
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-104
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-104
Coaxial Patch Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-105
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-105
Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-106
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-106
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-106
Coaxial Cable Assemblies (Equipment Cords and Patch Cords) . . . . . . . . . . . . . 6-107
Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-107
Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-107
Advantages and Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-107
Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-107
TDMM, 14th edition
6-vi
© 2020 BICSJ:®
Chapter 6: ICT Cables and Connecting Hardware
Figures
Figure 6.1
Balanced twisted-pair cable construction types . . . . . . . . . . . . . . . . . . . 6-6
Figure 6.2
Examples of balanced twisted-pair cables . . . . . . . . . . . . . . . . . . . . . . 6-7
Figure 6.3
Multimode optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
Figure 6.4
Singlemode optical fiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-17
Figure 6.5
Side view of a loose-tube optical fiber cable . . . . . . . . . . . . . . . . . . . . 6-19
Figure 6.6
Loose-tube furcating harness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19
Figure 6.7
Loose-tube optical fiber cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Figure 6.8
Tight-buffered optical fiber cable, distribution construction . . . . . . . . . . 6-21
Figure 6.9
Tight-buffered optical fiber cable, breakout construction . . . . . . . . . . . 6-22
Figure 6.10
Series-6 quad shield (screen) coaxial cable . . . . . . . . . . . . . . . . . . . . 6-24
Figure 6.11
Classification of cables and wires according to the NEC . . . . . . . . . . . . 6-30
Figure 6.12
110-style IDC connector design . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
Figure 6.13
Examples of 66-style connector designs. . . . . . . . . . . . . . . . . . . . . . . 6-37
Figure 6.14
BIX-style IDC connector design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40
Figure 6.15
Examples of LSA-style connector designs . . . . . . . . . . . . . . . . . . . . . . 6-42
Figure 6.16
8P8C unkeyed modular plug. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45
Figure 6.17
8P8C modular plugs for stranded and solid conductors . . . . . . . . . . . . 6-46
Figure 6.18
8P8C modular jack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Figure 6.19
Modular jack design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Figure 6.20
Eight-position jack pin/pair assignments (front view) . . . . . . . . . . . . . 6-49
Figure 6.21
50-position miniature ribbon connector . . . . . . . . . . . . . . . . . . . . . . . 6-51
Figure 6.22
50-position miniature ribbon connector design . . . . . . . . . . . . . . . . . . 6-52
Figure 6.23
Telecommunications outlet/connectors . . . . . . . . . . . . . . . . . . . . . . . . 6-55
Figure 6.24
Examples of work area telecommunications outlet designs . . . . . . . . . . 6-56
Figure 6.25
Rack-mount
Figure 6.26
Modular patch panel with cable management bar installed in an
~483 mm (19 in) equipment rack . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-59
Figure 6.27
66-style block, 89-style mounting brackets, and a distribution
frame with installed 66-style blocks . . . . . . . . . . . . . . . . . . . . . . . . . 6-61
Figure 6.28
110-style wiring blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-63
Figure 6.29
BIX-style connecting blocks mounted in a distribution frame ........ 6-66
Figure 6.30
25-pair BIX-style connecting strip . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-67
Figure 6.31
LSA-style connecting blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-68
Figure 6.32
10-pair LSA-style connecting block . . . . . . . . . . . . . . . . . . . . . . . . . . 6-69
Figure 6.33
Hybrid equipment cord assembly or hybrid patch cord assembly ...... 6-71
Figure 6.34
Example of MS2 and Type 710 IDC connector splicing contacts ....... 6-73
Figure 6.35
Example of single-pair splice connectors and modules . . . . . . . . . . . . . 6-74
Figure 6.36
Example of multipair splice connectors and modules . . . . . . . . . . . . . . 6-75
© 2020 BICSI®
~483
mm (19 in) modular patch panel . . . . . . . . . . . . . . 6-57
6-vii
TDMM, 14th edition
Chapter 6: ICT Cables and Connecting Hardware
Figure 6.37
LC-style optical fiber adapters and connectors . . . . . . . . . . . . . . . . . . 6-80
Figure 6.38
SC-style optical fiber adapters and connectors . . . . . . . . . . . . . . . . . . 6-81
Figure 6.39
ST-style optical fiber connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-83
Figure 6.40
Array-style optical fiber connector and adapter (example of
Type-A MPO configuration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-84
Figure 6.41
Array-style optical fiber connector and adapter (example of
Type-B MPO configuration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-84
Figure 6.42
Fusion splicer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-85
Figure 6.43
Mechanical splice open position . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-86
Figure 6.44
Optical fiber pigtail splicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87
Figure 6.45
Cross-connection of optical fiber cabling segments (first- and
second-level backbone) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-90
Figure 6.46
Interconnection of equipment to backbone cabling . . . . . . . . . . . . . . . 6-91
Figure 6.47
Hybrid optical fiber patch cord assembly . . . . . . . . . . . . . . . . . . . . . . 6-92
Figure 6.48
BNC-style connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-95
Figure 6.49
BNC-style connector components . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-96
Figure 6.50
Figure 6.51
BNC-style connector plug and jack . . . . . . . . . . . . . . . . . . . . . . . . . . 6-96
50-ohm and 75-ohm bayonet BNC-style connectors . . . . . . . . . . . . . . 6-97
Figure 6.52
One-piece crimp-style F-style connector . . . . . . . . . . . . . . . . . . . . . . 6-99
Figure 6.53
N-style coaxial connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-101
Figure 6.54
Standard wall-mount multimedia and modular furniture
multimedia outlets featuring F-style coaxial connectors . . . . . . . . . . . 6-103
Figure 6.55
BNC-style bracket mount and F-style ~483 mm (19 in) rack-mount
coaxial patch panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-105
TDMM, 14th edition
6-viii
© 2020 BICSI®
Chapter 6: ICT Cables and Connecting Hardware
Tables
Table 6.1
Comparison of the terms class and category within ISO/IEC and
TIA standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Table 6.2
Balanced twisted-pair cabling channel performance . . . . . . . . . . . . . . . . 6-4
Table 6.3
Table 6.4
Balanced twisted-pair cable designations . . . . . . . . . . . . . . . . . . . . . . . 6-4
Balanced cable designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Table 6.5
Optical fiber cable transmission performance parameters . . . . . . . . . . . 6-15
Table 6.6
Typical distances supported by optical fiber cabling . . . . . . . . . . . . . . . 6-18
Table 6.7
Examples of regional fire safety standards . . . . . . . . . . . . . . . . . . . . . 6-27
Table 6.8
Communications cable types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28
Table 6.9
Optical fiber cable types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29
Table 6.10
Table 6.11
Interclass relativity of NEC and IEC fire safety specifications ........ 6-31
Comparison between NEC CM ratings and CSA FT requirements . . . . . . 6-32
Table 6.12
Connecting hardware transmission performance categories for
110-style connector-based connecting hardware . . . . . . . . . . . . . . . . . 6-35
Table 6.13
Connecting hardware transmission performance categories . . . . . . . . . 6-38
Table 6.14
Connecting hardware transmission performance categories for
SIX-style connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40
Table 6.15
Connecting hardware transmission performance categories for
LSA-style connector-based connecting hardware. . . . . . . . . . . . . . . . . 6-43
Table 6.16
Modular plug transmission performance categories . . . . . . . . . . . . . . . 6-47
Table 6.17
Modular jack transmission performance categories . . . . . . . . . . . . . . . 6-50
Table 6.18
50-position miniature ribbon connector transmission performance
categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Table 6.19
Optical fiber link transmission performance calculations worksheet .... 6-78
Table 6.20
Splice insertion loss guidelines and objectives . . . . . . . . . . . . . . . . . . 6-86
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Chapter 6: ICT Cables and Connecting Hardware
ICT Cables and Connecti
Hardware
Introduction
A cabling system consists of cables, equipment cords, patch cords, and connecting hardware
components. All balanced twisted-pair, optical fiber, and coaxial cabling systems are made
up of such components. These cabling components and resulting cabling systems are used in
OSP and premises cabling (also known as ISP) environments.
Although equipment cords and patch cords may be identical cable assemblies, the distinction
between the two is generally accepted:
• Equipment cords attach directly to active equipment (e.g., network switch, computer).
• Patch cords are used to cross-connect passive cabling infrastructure (e.g., patch panel to
patch panel).
Requirements
The fCT distribution designer should carefully assess customer requirements before selecting
the style of cabling for a given project. Some of these customer requirements may include
the:
• Number of user work areas and telecommunications spaces used to serve the building
occupants.
• Number of telecommunications outlets/connectors desired at each user work area.
• Number and styles of user equipment (e.g., telephony, LAN, building automation).
• Cabling system transmission performance expectations.
• Backbone distances involved in the building or campus design.
• Future growth expectations (e.g., 15 to 20 percent recommended minimum growth factor).
• Environmental conditions that may influence the selection of cabling components.
Selecting the appropriate style of cabling is critical to the success of a design. If customer
requirements cannot be determined, a survey should be conducted.
Balanced twisted-pair and optical fiber cabling may be divided into two general
environmental styles-OSP and premises (ISP). Each of these two styles may be broken
down further into several subsets.
For example, several performance categories and classes of l 00-ohm balanced twisted-pair
cabling are available, ranging from category 3/class C to category 8. Cable and connecting
hardware categories are specified in applicable standards. The ICT distribution designer
should specify the applicable standards that define the transmission characteristics for a given
style of cabling (e.g., ISO/lEC 11801-1, ANSl/TJA 568.2 ).
© 2.020 BICSI®
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Chapter 6: ICT Cables and Connecting Hardware
Requirements, continued
For balanced twisted-pair and optical fiber cabling, the connecting hardware, equipment
cords, and patch cords used in horizontal and backbone cabling channels must be rated in the
same transmission performance classifkation as the corresponding horizontal and backbone
cables or in a higher performance classification than that of the cable. This will provide some
assurance to the customer that the installed cables will not perform to lower performance
levels as a result of being attached to lower performing connecting hardware, equipment
cords, and patch cords.
For detailed information on transmission principles, see Chapter I: Principles of
Transmission. For detailed information on the effects of EMf and electromagnetic
compatibility, see Chapter 2: Electromagnetic Compatibility.
Environmental
Telecommunications cabling components may be required to comply with a unique set
of codes, standards, and regulations when used in environmentally harsh conditions. One
such example is IEC 60529, Degrees ()/Protection Provided by Enclosures (JP Code). This
document applies to the classification of degrees of protection provided by enclosures for
electrical equipment with a rated voltage not exceeding 72.5 kilovolts. It has the status of a
basic safety publication in accordance with IEC Guide 104.
fEC 60529 specifies an international classification system fix the sealing effectiveness of
enclosures of electrical equipment against the intrusion into the equipment of foreign bodies
(e.g., tools, dust, fingers) and moisture. 'I'his classification system utilizes the letters IP
(ingress protection) followed by two digits. An X is used for one of the digits if there is only
one class of protection (e.g., lP X4, which addresses moisture resistance only.)
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Chapter 6: ICT Cables and Connecting Hardware
Balanced Twisted-Pair Cables
Classification of Cables by Their Transmission Performance
The transmission performance of balanced twisted-pair cabling and its associated components
are based on a number of factors within the cabling or component design. Through the
standards development work of the TfA, as well as the joint work between the ISO and the
IEC, minimum performance levels for balanced twisted-pair cabling and components have
been created. 'T'hese performance levels use the terms category and class.
Within the standards generated by TIA and ISO/IEC, there are difierences in the definition
and applicability of category. For example, the standards developed by TIA only use the term
category, whereas standards developed by ISO/IEC utilize both class and category, depending
on the specific cabling element being described. Table 6.1 provides a comparison between the
terms category and class as used within the standards of each group.
Table 6.1
Comparison of the terms class and category within ISO/IEC and TIA standards
Standards
Development
Organization
Components
(cable and connecting
hardware performance)
Cabling
(channel and link
performance)
ISO/IEC
Category
Class
TIA
Category
Category
IEC = International Electrotechnical Commission
ISO = International Organization for Standardization
TIA = Telecommunications Industry Association
While category Se/class Dis the minimum acceptable performance level for network cabling,
category 6)class EA cabling is the recommended performance by many standards to service
the majority ofthe current applications (see Table 6.2). BICSI recommends using category
6 )class EA as the minimum performance level for horizontal balanced twisted-pair cabling.
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables by Physical Makeup
Table 6.2
Balanced twisted-pair cabling channel performance
ISO Category/Class
TIA Category
Frequency
Category 3/class C
Category 3
16MHz
Category 5/class D
Category 5e
100 MHz
Category 6/class E
Category 6
250 MHz
Category 6A/class EA
Category 6A
500 MHz
Category 7/class F
**
600 MHz
Category 7A/class FA
**
1000 MHz
Category 8.1 /Class I*
Category 8
2000 MHz
Category 8.2/Ciass IV
N/A
2000 MHz
*
Backwards compatible with category 6A/Ciass EA using 8P8C connectors.
Category 7 performance is not defined by TIA.
A Inoperable with category 7A/class FA.
ISO = International Organization for Standardization
TIA = Telecommunications Industry Association
**
A large number of cable designs are used in the telecommunications industry, resulting in
numerous names and acronyms for their identification.
ISO/TEC 11801-1 describes balanced twisted-pair cable designations using an x/y designation
where x is the overall screen type andy is the individual pair screen type (see Table 6.3).
Table 6.3
Balanced twisted-pair cable designations
y:
x:
u
Overall screen absent
U Individual screens absent
F
Overall foil screen
F Individual foil screens
S
Overall braid screen
SF
Dual overall screen (foil braid)
There are no clear cable design designations in the ANSI/TfA standards. The two most
frequently used ANSJ/TlA cable design descriptions are UTP and ScTP. Table 6.4 offers
several examples of cable type acronyms and specific features related to their construction.
Figure 6.1 illustrates balanced twisted-pair cable construction types.
It should be noted that designations cannot be applied in the same manner to connecting
hardware because of significant design differences. In general, connecting hardware should be
referenced as unscreened or screened; UTP and STP or FTP also may be appropriate.
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables by Physical Makeup, continued
Table 6.4
Balanced cable designs
Global
Abbreviations
North
American
Abbreviation
U/UTP
UTP
No
No
No
U/FTP
STP
No
No
Yes
F!UTP
FTP, ScTP, PiMF
No
Yes
No
F/FTP
STP, SSTP
No
Yes
Yes
S/UTP
STP
Yes
No
No
S/FTP
STP, SSTP
Yes
No
Yes
SF!UTP
STP, SSTP
Yes
Yes
No
SF/FTP
STP, SSTP
Yes
Yes
Yes
Overall Braid
Screen
Overall Foil
Screen
Individual Foil
Screen
F/FTP =Foil-screened foil-screened twisted-pair. (Individually foil-screened twisted-pair in overall foil screen.)
F/UTP =Foil-screened unscreened twisted-pair. (Unscreened twisted-pair in overall foil screen.)
PiMF =Pairs in metal foil. (Individually foil-screened twisted-pair in overall foil screen.)
S/FTP =Braid-screened foil-screened twisted-pair. (Individually foil-screened twisted-pair in overall braid screen.)
S/UTP =Braid-screened unscreened twisted-pair. (Unscreened twisted-pair in overall braid screen.)
ScTP =Screened twisted-pair
SF/FTP = Braid-screened-foil-screened foil-screened twisted-pair. (Individually foil-screened twisted-pair in overall foil
and braid screen.)
SF/UTP = Braid-screened-foil-screened unscreened twisted-pair. (Unscreened twisted-pair in overall foil and braid
screen.)
U/FTP = Unscreened foil-screened twisted-pair. (Individually foil-screened twisted-pair.)
U/UTP =Overall unshielded twisted-pair with unshielded twisted-pair
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables by Physical Makeup, continued
Figure 6.1
Balanced twisted - pair cable construction types
U/UTP
U/FTP
"'ffi!llr--- Outer jacket
~1!11'1r---
""""'~- Conductor
1--lWiil~-
Insulation
Outer jacket
Conductor
Insulation
Twisted-pair
Tw isted - pair
Foil screen
Outer jacket
t-'l~r---
Conductor
Insulation
Twisted - pair
Outer jacket
,_.~r---
Conductor
Twisted-pair
41li"+-- Twisted - pair
B -..J--- Foil screen
SF/UTP
SF/FTP
Outer jacket
Oute r jacket
Conductor
Conductor
Foil screen
Insulation
Insulation
Twisted-pair
Foil screen
Braid screen
F/FTP
F/UTP
S/FTP
S/UTP
SF/FTP
SF/UTP
U/FTP
U/UTP
Twisted-pair
Foil screen
Braid screen
= Foil-screened foil-screened twisted-pair
= Foil-screened unscreened twisted -pair
= Braid-screened foil - screened twisted-pair
= Braid -screened unscreened twisted-pair
= Braid-screened-foil-screened foil-screened twisted-pair
= Braid-screened-foil-screened unscreened twisted -pair
= Unscreened foil-screened twisted-pair
= Overall unshielded twisted-pair with unshielded twisted-pair
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Chapter 6: ICT Cables and Connecting Hardware
four-Pair Cables and Multipair Cables
Balanced twisted-pair cable (i.e., 4-pair and multipair):
• Is composed of insulated conductors twisted together to form circuit pairs.
• Generally has a characteristic impedance of 100 ohms(± 15 ohms).
• Has conductor sizes of 22 AWG to 26 AWG.
• Has an overall sheath designed for applicable environments.
• May have individually screened pairs or overall screen.
See Figure 6.2 for examples of balanced twisted-pair cables.
Figure 6.2
Examples of balanced twisted-pair cables
Unscreened (unshielded)
twisted-pair cable
Cable jacket_/
Screened (shielded) twisted-pair
Drain w i r e \
~Cable jacket
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Chapter 6: ICT Cables and Connecting Hardware
Design
All balanced twisted-pair cables consist ofthe following components:
• Solid or stranded conductors
• Thermoplastic insulation
• Outer jacket or sheath
Optionally, these cables may consist of:
• One or more styles of shielding (with or without drain wire).
• Strength members.
• Pair separators.
• Rip cords.
Conductor materials are drawn to various sizes described here in millimeters and duplicated
in AWG. For example, a common conductor size for premises cables is 24 AWG.
These conductors may consist of:
• Bare copper.
• Copper alloys.
• Copper-clad steel.
• Copper-clad aluminum.
• Aluminum-plated copper.
• Tin-plated copper.
• Silver-plated copper.
Selection of dielectric material for conductor insulation involves economics as well as
tradeoffs in characteristics desired for the application and installation environment. An
electrically efficient insulation is nearly always desired, but a tradeoff may be required to
obtain insulation capable of meeting fire protection cable requirements (e.g., CMR and CMP
rated cables). Similarly, less effective insulation may be used to secure more physically robust
characteristics.
NOTE: Efficient insulation is defined as material where any loss of the transmitted signal
because of loss associated with the insulation is minimal.
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Chapter 6: ICT Cables and Connecting Hardware
Design, continued
Insulating materials can affect the physical size of the completed cable and determine two of
the four primary electrical characteristics of the balanced twisted-pair:
• Mutual capacitance
• Permittivity
Mutual capacitance depends on the conductor's insulating material as well as the insulation's
thickness (diameter). The style and thickness of the dielectric insulation are carefully selected
by cable manufacturers and carefully controlled in the manufacturing process. Insulated
conductors are designed to form balanced twisted-pairs, which form a cable assembly. Once
again, the assembling of insulated conductors that are used to form a cable is carefully
controlled in the manufacturing process.
Permittivity indicates the insulation's ability to transmit (or permit) an electric field.
Permittivity is directly related to electrical susceptibility. A number of styles of dielectric
insulation (e.g., plastics) are used to build a cable. Some of these dielectric insulating
materials include:
• Halogenous:
- Polyvinyl chloride
- Fluorinated ethylene propylene
-Ethylene tetrafluoroethylene
- Polychloroprene
- Chlorosulfonated polyethylene
• Nonhalogenous:
- Polyethylene
- Polyurethane
- Polypropylene
Silicone rubber
The insulated conductors in a balanced twisted-pair cable are twisted at a rate and to a pitch
that achieve the manufacturer's transmission performance objectives.
© 2020 BICSI®
TDMM, 14th edition
Chapter 6: ICT Cables and Connecting Hardware
Characteristics
A number of measurable characteristics control the transmission performance of a cable.
Some of these transmission parameters include the following:
• Primary parameters, which depend on the physical nature of the conductor-materials
(conductivity and permittivity) and dimensions (wire gauge [copper diameter], insulation
diameter and thickness, conductor spacing)-are:
- Resistance (R).
-Conductance (G).
-Inductance (L).
-Capacitance (C).
• Secondary parameters, which are calculated based on the primary parameters or measured
directly, are:
- Insertion loss.
- Crosstalk loss subset of parameters:
• Pair-to-pair near-end crosstalk loss
• Power-sum near-end crosstalk loss
• Pair-to-pair attenuation-to-crosstalk ratio, far end
• Power-sum attenuation-to-crosstalk ratio, far end
• PSANEXT loss
• Average PSANEX'f loss
• PSAACRF
• Average PSAACRF
-RL.
- Propagation delay.
-Propagation delay skew.
-Nominal velocity of propagation.
Additional mechanical cable characteristics that need to be considered include:
• Tensile strength.
• Temperature rating.
• Flammability rating (e.g., CMP, CMR, LSZH).
• Environmental impact resistance.
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Chapter 6: ICT Cables and Connecting Hardware
Characteristics, continued
Screened cables typically contain similar elements as unscreened cables, but screened cables
radiate less electromagnetic energy, which can interfere with signals in other nearby cables
because of the screen's ability to absorb and divert it. Screened cabling also helps to protect
the signal integrity from external interference in electrically noisy environments such as:
• Industrial factory floors.
• High-voltage or high-current electrical equipment or components proximity.
• High concentration of electrical equipment.
• Where secure communications are desired.
Two common styles of screening used in balanced twisted-pair cables are foil and braid
(see Figure 6.2).
Screening improves a cable's performance in environments that experience unusually high
effects of EMT. Consider the difference between foil and braid screens in these environments.
Copper cabling may or may not have a metallic covering (screen) over the pairs. Certain
systems use screened cables or screened pairs. Backbone cables may use an overall screen.
The term screen is synonymous with the term shield. The screen is used to:
• Reduce the level of the signal radiated from the cable.
• Minimize the effect of external EMI on the cable pairs.
• Provide physical protection.
The screening material type, thickness, and relative coverage (i.e., limited number of
perforations) determines the effectiveness of meeting the screen's goals. Styles of screens
include:
• Metal foil.
• Copper braid.
• Solid metallic sleeve.
• Drain wire.
• CBC.
The screen's characteristics are such that the:
• Foil typically blocks higher frequency (30 MHz and higher) electromagnetic fields.
• Copper braid effectively blocks lower frequency (below 30 MHz) electromagnetic fields.
• Solid metal tubing blocks almost any electromagnetic field. (For effective tubing wall
thickness, refer to Chapter 2: Electromagnetic Compatibility.)
• The drain wire drains the current induced on the screen.
• CBC may help divert electromagnetic fields in a wide frequency range from susceptible
cables.
NOTE: CBC effectiveness depends on many factors and effectiveness may vary in the field.
© 2020 BICSI®
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Chapter 6: ICT Cables and Connecting Hardware
Effectiveness of Screens
Screens are most effective when continuity is ensured and they are bonded according to the
manufacturer's instructions and in accordance with or exceeding applicable codes, standards,
regulations, and AHJ rulings. Screen effectiveness depends on many factors, including
frequency, screen thickness, and braid density.
Generally, in environments with unusually strong effects from relatively low-frequency EMI:
• A combination of braid and foil screens provides the highest level of protection.
• Braid screens with high coverage are more effective than foil screens.
• Only thick-wall metal conduit is effective for very low frequencies (e.g., less than
I kilohertz).
• Screen resistance is critical, and foil screens are not the best choice because screen foil is
usually thin (less than:.::; I mm [0.04 in]).
Generally, in environments with unusually strong etTects from relatively high-frequency EMI:
• Foil screens are more effective than braid screens.
• Braid screens become wavelength dependent.
• Spaces in the braid screen allow high frequencies in or out.
Typical Applications
Four-pair screened cabling is recognized for use in horizontal and backbone cabling
applications. Multipair screened cabling (i.e., constructed with more than four pairs) is
recognized for use in backbone cabling applications only. Screened cables that offer pair
counts starting at 25 pairs and extending up to 400 pairs in premises to beyond 2400 pairs in
OSP in increments of25 pairs are typically used in backbone applications.
Four-Pair Cordage
Balanced twisted-pair patch cords:
• Typically have stranded conductors for added flexibility.
• That are stranded may exhibit 20 percent (ANSI/TIA) to 50 percent (ISO/IEC) more
attenuation than solid conductors.
• Shall meet the same or higher performance category as the horizontal cabling in use.
• Typically have 8P8C connectors on the ends.
• Must be balanced twisted-pair construction.
Four-pair cordage is implemented in manufacturing cable assemblies (equipment and patch
cords), which are used for electrical connection between two pieces of equipment or between
one piece of equipment and the passive cabling system to which it connects.
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Chapter 6: ICT Cables and Connecting Hardware
Four-Pair Cordage, continued
Design
Four-pair cords may be constructed with solid or stranded conductors. Although patch cord
assemblies are typically double ended and fitted with connecting hardware on each end, patch
cord assemblies may be single ended as well.
The term equipment cord is used to distinguish those cords that directly attach to equipment
on one or both ends.
The term patch cord is used to distinguish those cords that attach one set of connecting
hardware to another set of connecting hardware to form a cross-connection, also known as a
distributor.
Patch cord assemblies may feature color-coding options, making them easily distinguishable.
Characteristics
Patch cord assemblies and equipment cord assemblies are compliant to the transmission
characteristics of the cabling components to which they attach. These assemblies are available
in OSP and premises (TSP) environments. Screened and unscreened styles are available in
most categories of cabling. Consider performance specifications of applicable standards
(i.e., ANSJ/TIA-568.2 and ISO/IEC 11801-1 ).
Selection of Solid versus Stranded Conductor Patch Cords
Solid conductor patch cord assemblies and solid conductor equipment cord assemblies
typically feature better insertion loss (i.e., attenuation) characteristics than stranded
assemblies of the same style and length.
Stranded conductor patch cord assemblies and stranded conductor equipment cord assemblies
typically feature better flex life characteristics (i.e., less prone to breaking from repeated
flexing) than solid assemblies of the same style and length.
Typical Applications
Double-ended equipment cords typically attach from one piece of equipment directly to
connecting hardware or directly to another piece of equipment.
Double-ended patch cords typically attach from one piece of connecting hardware directly to
another piece of connecting hardware.
Single-ended equipment cords typically attach from one piece of equipment directly to the
back or bottom of connecting hardware. The end opposite the equipment is known as the
permanent cabling connection, and it is not used for frequent connections or disconnections.
Patch cords are typically used between two pieces of connecting hardware because a
cross-connection should offer the highest degree of flexibility for frequent connections or
disconnections.
© 2020 BICSI®
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Chapter 6: ICT Cables and Connecting Hardware
0
I Fiber Cables
Overview
Optical fiber cables are used in backbone and horizontal cabling applications. When an alldielectric construction is desirable, optical fiber cable offers characteristics that can make
them the media of choice. Transmission of information through optical fiber cables is not
degraded by crosstalk, ambient noise, lightning, and most EMI problems. However, like
balanced twisted-pair cables, attenuation (loss of signal) and environmental considerations
are of concern for optical fiber cabling systems.
The primary difference between balanced twisted-pair and optical fiber as a transmission
medium is that pulses of light consisting of photons are injected into the optical fiber as
opposed to the electron flow in a balanced twisted-pair cable.
Optical fibers are classified as either singlemode or multimode. Singlemode optical fibers
have a relatively small diameter featuring a core of 8 to II ~un and a cladding diameter
of approximately 125 ~un. Lasers have a narrow light beam and can focus I 00 percent of
the light beam down the core of the optical fiber. Multimode has a larger core diameter
(e.g., 50 ~un or 62.5 ~un) with the cladding of approximately 125 ~tm. The light is restricted
to a single path or mode in singlemode optical fibers, whereas the larger diameter multimode
has many paths or modes. Table 6.5 displays the transmission performance parameters of
optical fiber cable.
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Chapter 6: ICT Cables and Connecting Hardware
Overview, continued
Table 6.5
Optical fiber cable transmission performance parameters
Optical Fiber Cable Type
Wavelength,
Maximum Attenuation,
nm
dB/km
Bandwidth,
MHz-km
62.5/125-~tm multimode cable (OMl)
(grandfath ered)
850
1300
3.5
1.5
200 (OFL)
500
50/125-!lm multimode cable (OM2)
(grandfathered)
850
1300
3.5
1.5
500 (OFL)
500
501125-!lm multimode cable (OM3)
850
3.5
1300
1.5
1500 (OFL)
2000 (EMB)
500
850
3.5
1300
1.5
850/880
910/940
3.0
3500 (OFL)
4700 (EMB) at 850
Singlemode cable (OS I)
(grand fathered)
1310
1550
1.0
1.0
N/A
N/A
Singlemode cable (OS 1a)
1310
1383
1550
1.0
1.0
1.0
N/A
N/A
N/A
Singlemode cable (0S2)
1310
1383
1550
0.4
0.4
0.4
N/A
N/A
N/A
50/125-~un
50/125-~tm
EMB =
N/A =
OFL =
OM =
OS=
multimode cable (OM4)
multimode cable (OMS)
3500 (OFL)
4700 (EMB)
500
Effective modal bandwidth
Not applicable
Overfilled launch
Optical multimode
Optical singlemode
NOTE: The basic difference between OS 1 and OS2 classes of cables is the cable
construction, not the transmission performance of optical fibers used to build them.
Originally, OS 1 was designed and applied to inside plant tight-buffered cable
construction while OS2 was designed and applied to loose-tube or blown fiber
solutions (where the cabling process applied no stress to the optical fibers). OS!
cables are grandfathered and not recommended to use in new applications. OS I a
cables are based on Bl.l, B1.3, or B6_a class optical fibers and the attenuation at
1383 nm (water peak) is defined at 1.0 dB/Km. OS2 cables are based on B 1.3 or
B6_a optical fibers, the attenuation ratio is lowered to 0.4 dB/Km at 1310/1550 nm
and newly defined to 0.4 dB/Km at 1383 nm.
© 2020 BICSI®
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Chapter 6: ICT Cables and Connecting Hardware
Overview, continued
Design
Physical protection is provided through the cable design and yarns that run alongside the
optical fiber strands in the cable. Physical protection is also provided by using different
materials for the jacket layers (e.g., glass-reinforced plastic rods, corrugated steel tape, and
steel wire armor).
Environmental protection is provided through materials in the cable jacket. These materials
could include water-blocking gel or tapes to stop migration of water along the inside of
the cable and define the fire rating of the jacket for the application (e.g., indoor or outdoor
cables).
The three classification terms used to describe the optical fiber cable are:
• Indoor/outdoor optical fiber cable~--Optical fiber cables designed to meet the requirements
of both indoor and outdoor environments to ease the transition from premises (fSP) to OSP
often carry a specific fire rating based on their internal fire performance.
• Indoor optical fiber cable-Cables designed to meet the requirements of indoor
environments and carry a specific fire rating.
• Outdoor optical fiber cable-Cables designed to meet the requirements of outdoor
environments and generally carry no fire rating.
Multimode optical fiber cable (see Figure 6.3):
• ls the most common for backbone and horizontal runs within buildings and campus
environments.
• Has a 50 f.lm or 62.5 f.lm core and 125 f.lm cladding diameter. 62.5
recommended for extensions to existing installations.
~tm
core fiber is only
NOTE: Distances supported are application dependent.
• Normally uses a VCSEL or LED for a light source.
• Supports common wavelengths of 850 nm VCSEL and 1300 nm LED.
Most transmission over MMF uses VCSEL light sources (850 nm); exceptions
include 100BASE-FX (1300 nm LED) and lOOOBASE-LX (1300 nm LD).
Figure 6.3
Multimode optical fiber
Core (50 !Jm)
Cladding (125 1-1m)
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Chapter 6: ICT Cables and Connecting Hardware
Overview, continued
Singlemode optical fiber cable (see Figure 6.4):
• Is commonly used in riser and campus environments and has been recognized as medium
for horizontal applications.
• Has an 8- to 10-~tm core, depending on the manufacturer.
• May be used for distances up to ;:::;3000 m (9840 ft) for structured cabling systems.
NOTE: Distances supported are application dependent.
• Normally uses a laser light source.
• Supports common wavelengths of 1310 nm, 1490 nm, 1550 nm, and 1625 nm.
Figure 6.4
Singlemode optical Aber
Core (8-10
~m)
Cladding (125
~m)
Characteristics
Light pulses in optical fiber cables are subject to loss in the magnitude as the light pulses
travel along the optical fiber. This transmission characteristic known as attenuation occurs as
a result of scattering of photons (e.g., deflection, absorption, backscattering) caused by:
• Glass material, impurities, and point defects.
• Macrobends and microbends in the fiber strands.
• In rare cases, nuclear radiation (point defects).
Optical fiber attenuation, which is measured in decibels, depends on the optical fiber
attenuation factor, which is expressed in decibels per kilometer. This is affected by the
wavelength of the light comprising the pulse. Therefore, optical fiber attenuation is directly
proportional to length.
Consider optical fiber performance specifications defined in applicable standards
(i.e., ANST/TIA-568.3 and ISO/IEC 11801-1 ). Multi mode and singlemode optical fiber
cables should perform as shown in Table 6.5.
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Chapter 6: ICT Cables and Connecting Hardware
Overview, continued
The information-carrying capacity of a transmission channel depends on its bandwidth.
The end-to-end bandwidth of a system corresponds to the respective bandwidths of its
component parts. The bandwidth or capacity of a transmission channel also varies depending
on its length. The modal bandwidth of an optical fiber provides a measure of the amount
of information an optical fiber is capable oftransporting. Modal bandwidth is measured
in MHz•km. The modal bandwidth of a multi mode optical fiber is defined as the frequency at
which the light pulse amplitude drops 3 dB at an;:::;] km (0.625mi) distance.
Increasing either the transmission distance (cable length) or the modulation frequency of the
light source decreases the bandwidth and, therefore, lowers the information-carrying capacity
of the optical fiber cable with a given modal bandwidth.
Overall bandwidth of optical fiber is a derivative of two components: modal dispersion
and chromatic dispersion (which is subdivided into material dispersion and waveguide
dispersion). In multimode, modal dispersion predominates, and chromatic dispersion is
negligible; in singlemode, it is the opposite. Therefore, singlemode optical fiber cable is
characterized by a transmission characteristic known as chromatic dispersion expressed in
ps/nm•km, which is a reciprocal bandwidth. Since it is not feasible to theoretically determine
the bandwidth limit of singlemode optical fiber, there are no standard requirements toward
singlemode optical fiber bandwidth. From a practical point of view, singlemode optical
fiber can be considered to have unlimited bandwidth. For all known telecommunications
applications, singlemode optical fiber will always be distance limited by attenuation only.
Optical fiber cabling applications are length restricted based on the style of cabling used.
Table 6.6 provides typical distances supported by varying optical fiber cables. Specific
applications may decrease the maximum distance supported.
Table 6.6
Typical distances supported by optical Aber cabling
Transmission
Standards
OMl
OM2
OM3
OM4
OMS
Singlemode
;:::;SSOm
(1800 ft)
;:::;550m
(1800 ft)
N/A
N/A
(1800 ft)
;:::;SSOm
(!800ft)
1Gb
;:::;220m
(722ft)
;:::;550m
(1800 ft)
;:::;SSOm
(1800 ft)
;:::;)000 m
(3281 ft)
N/A
;:::;10,000 111
(32,800 ft)
lOGb
;:::;33m
(I 08 ft)
;:::;82m
(269ft)
;:::;300m
(984ft)
;:::;SSOm
( 1800 ft)
;:::;SSOm
(1800 ft)
;:::;]0,000 m
(32,800 ft)
40Gb
N/A
N/A
;:::;100m
(328 ft)
;:::;JSOm
(500ft)
;:::;JSO m
(500ft)
;:::;10,000 m
(32,800 ft)
100Gb
N/A
N/A
;:::;JOOm
(328 ft)
;:::;JSOm
(500 ft)
;:::;ISO m
(500ft)
;:::;)0,000 m
(32,800 ft)
lOOMb
~ssom
N/A == Not applicable
OM = Optical multimode
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Chapter 6: ICT Cables and Connecting Hardware
loose-Tube Optical Fiber Cables
Loose-tube optical fiber cable (see Figure 6.5):
• Is used primarily outdoors.
• May contain water-blocking elements (e.g., water absorbent tapes or gel) for OSP use.
• Allows the cable jacket to expand or contract with changes in temperature without affecting
the optical fibers.
• Has a different cable jacket length to the optical fiber length inside; fiber length is typically
longer than the cable jacket, depending on the construction of the cable.
• May be singlemode or multimode.
• Has the most common loose-tube optical fiber diameter of250
are available.
~un,
although other diameters
• Typically contains buffer tubes with 4, 6, or 12 strands.
• May require furcation tubing to allow direct connectorization (see Figure 6.6 ).
Figure 6.5
Side view of a loose-tube optical fiber cable
Figure 6.6
Loose-tube furcating harness
y---"/'1
u
_l)
Ti
{)
900 f-Jm outer diameter furcation tubing
The cable jacket on an optical fiber cable (see Figure 6.7) serves two main functions:
• Physical protection for the optical fibers in the cable
• Environmental protection for the optical fibers in the cable
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Chapter 6: ICT Cables and Connecting Hardware
loose-Tube Optical Fiber Cables, continued
Figure 6.7
Loose-tube optical fiber cable
Waterblocking material
Ripcord
Coated optical fiber
Loose buffer tube (filled)
Dielectric center member
Aramid strength member
Polyethylene outer sheath
Advantages and Disadvantages
A loose-tube optical fiber cable's advantages when compared with tight-buffered cables with
the same number of strands are:
• A greater tensile strength and more robust outer jacket.
• A greater resistance to low-temperature effects on attenuation.
• A cable jacket that expands or contracts with changes in temperature without affecting the
optical fiber.
A loose-tube optical fiber cable's disadvantages when compared with tight-butTered cables
with the same number of strands are:
• A larger outer cable diameter for optical fiber cables with less than 24 strands.
• A greater weight per unit length.
• A larger bend radius.
• A lower impact resistance for individual fiber strands.
• A lower crush resistance for individual fiber strands.
• Cables that require furcation tubing to allow direct connectorization.
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Chapter 6: ICT Cables and Connecting Hardware
loose-Tube Optical Fiber Cables, continued
Typical Applications
A loose-tube optical fiber cable's typical applications are:
• Long- and short-reach high bit-rate systems for telephony.
• Distribution and local networks for voice, data, and video services.
• Premises intrabuilding and interbuilding installations, including LANs, SANs, data centers,
PBXs, video, and various multiplexing uses.
• OSP telephone cable use.
• Security, HVAC monitoring, and facility systems.
Tight-Buffered Optical Fiber Cables
Tight-buffered optical fiber cable:
• Is primarily used inside buildings.
• May contain water blocking elements to be used in OSP applications.
• When designed for OSP use, allows the cable jacket to expand or contract with changes in
temperature without affecting the fibers.
• Is available with various jacket styles to satisfy the codes for OSP and premises
environments.
• Protects the optical fiber by supporting each strand of glass with a buffer coating extruded
over the base optical fiber's 250-~un acrylate coating. The most common tight-buffer
diameter is 900 )1m, although other diameters are available.
• Is easily connectorized for field termination without the need for furcation tubing.
• May be singlemode or multimode.
Design
Figure 6.8 and Figure 6.9 demonstrate the distribution and breakout styles of tight-buffered
optical fiber cables.
Figure 6.8
Tight-buffered optical fiber cable, distribution construction
Optical fiber
buffer
Tensile strength member
Outer jacket
Central member overcoat
Central member
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Chapter 6: ICT Cables and Connecting Hardware
Tight-Buffered Optical fiber Cables, continued
Figure 6.9
Tight-buffered optical fiber cable, breakout construction
Tensile strength
member
Tensile strength
member
Central member
overcoat
Advantages and Disadvantages
A tight-buffered optical fiber cable's advantages, compared with loose-tube cables with the
same number of strands, are:
• A smaller bend radius.
• A smaller outer cable diameter.
• A higher impact resistance.
• A higher crush resistance.
• A lower weight per unit length.
• When designed for OSP use, it allows the cable jacket to expand or contract with changes in
temperature without affecting the fibers.
• It is available with various jacket styles to satisfy codes for OSP and premises
environments.
• It protects the optical fiber by supporting each strand of glass with a buffer coating extruded
over the base optical fiber's 250-J-lm acrylate coating.
• It is easily connectorized for field termination without the need for furcation tubing.
A tight-buffered optical fiber cable's disadvantages, when compared with loose-tube cables
with the same number of strands, are a:
• Lower tensile strength.
• Greater attenuation increase at low temperatures.
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Tight-Buffered Optical Fiber Cables, continued
Typical Applications
A tight-buffered optical fiber cable's typical applications are:
• OSP telephone cable use.
• Short reach, high bit-rate systems for telephony.
• Distribution and local networks for voice, data, and video services.
• Premises intrabuilding and interbuilding installations, including LANs, SANs, data centers,
PBXs, video, and various multiplexing uses.
Optical Fiber Patch Cords
Design
Singlemode and multimode optical fiber cables that are used in the assembly of optical fiber
patch cords (i.e., optical fiber jumpers) should consist of optical fiber strands ofthe same type
(e.g., 50/125 ~-tm) and transmission performance characteristics (e.g., OM3) as the optical
fiber links to which they interconnect and cross-connect.
Characteristics
Factory-terminated duplex jumpers should comply with optical fiber performance
specifications as defined in applicable standards (i.e., ANSI/TIA-568.3 and
TSO/IEC 11 801-1 ).
Typical Applications
Optical fiber cordage's typical applications are:
• Multimode optical fiber cabling systems-Multimode cables are constructed from optical
fibers that are characterized for overfilled launch and restricted mode launch bandwidth to
ensure compatibility with both LED and VCSELs. Optical fibers should exhibit virtually
zero differential mode delay at the core so that mode conditioning launch cords are not
required to support VCSEL applications (e.g., I 0 Gb and 40 Gb Ethernet).
• Singlemode optical fiber cabling systems-Singlemode cables are well suited for the
support of extended distance I 0 Gb Ethernet (more than ;:::;550 m [ 1800 ft]) applications as
well as emerging applications, such as 40 Gb/s and I 00 Gb/s. Singlemode cables should be
constructed from optical fibers that exhibit low and stable insertion loss performance over
the entire operating range, including the 1383 nm water peak band, to ensure compatibility
with coarse wavelength division multiplexing and dense wavelength division multiplexing
applications.
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Chapter 6: ICT Cables and Connecting Hardware
Coaxial Cables
Overview
The predominant coaxial cables are Series-6, Series-ll, and RG 59. These coaxial cables
have a characteristic impedance of75 ohms. There may be special backbone applications
where a larger diameter cable is specified (e.g., 0.500, 0. 75 [hardline trunk]). While the
termination procedures may be similar, special attention must be paid to the manufacturer's
specific instructions for termination and connectors.
Design
Coaxial cable is unbalanced and consists of a centered inner conductor insulated from a
surrounding outer conductor and an overall jacket. The geometry of such a construction
inherently provides ~;educed external interference and radiation protection; however, the
metallic covering is not a screen-it is a conductor in the circuit.
Characteristics
Consider performance specifications as defined in applicable standards (e.g., ANSI/TIA
568.4). Series-6 coaxial cable is used for video, CATV, and security cameras (see
Figure 6. I0).
Figure 6.10
Series-6 quad shield (screen) coaxial cable
Copper braid
Series-6 has a(n):
• Characteristic impedance of75 ohms.
• Coated foil shield over the dielectric to shield against high frequencies.
• Braided shield over the coated foil to shield against low frequencies.
• Solid-center conductor.
• F-style or BNC connector.
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Characteristics, continued
Series-11 U is used in video backbone distribution. It has a lower signal attenuation than
Series-6, making it the preferred choice for longer runs. Series- II U has a(n):
• Characteristic impedance of 75 ohms.
• Coated foil shield over the dielectric to shield against high frequencies.
• Braided shield over the coated foil to shield against low frequencies.
• 18 AWG stranded center conductor.
• F-or N-style connector.
Attenuation is a phenomenon that depends on the cable size, the dielectric material, length of
cable, and frequency of the system. The longer the cable length, the greater the attenuation.
The higher the frequency, the greater the attenuation. For a given dielectric, the larger the
cable's outside diameter, the lower the attenuation. Attenuation is the key factor that an ICT
distribution designer must keep in mind when considering coaxial cable. It determines how
often the signal has to be amplified in the network.
The attenuation factor can be expressed as:
a=Bxj+AxYJ
Where:
A is the conductor loss.
B is the dielectric loss.
f
is the operating frequency.
For typical rigid copper coaxial cables, there are practically no dielectric losses, so:
a= 0.433/Z0 x (1/D + 1/d) x YJ
Where:
z() is the characteristic impedance.
D is the diameter of the outer conductor.
d is the diameter of the inner conductor.
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Chapter 6: ICT Cables and Connecting Hardware
Selection of Coaxial Cables
Coaxial cables of each series are available in a variety of configurations, including:
• Jacket styles.
• Shield configurations.
• Bandwidths.
• Attenuations.
A coaxial cable cannot be selected by simply identifying the physical size (series); a full
understanding of the application is necessary. Many supply houses and most manufacturers
offer consultation services to assist in the selection of the cable best suited for the job.
Typical Applications
Coaxial cable is used for computer networks, CATV, and video systems. Historically, coaxial
cable was designated as RG cable. Coaxial cables used in broadband applications are now
referred to as Series-X cables. The X designates the construction of the cable with such
factors as the:
• Center conductor diameter.
• Center conductor being solid or stranded.
• Dielectric composition.
• Outer braid's percent of coverage.
• Impedance.
An ICT distribution designer should consider the following factors when designing a
broadband distribution system:
• Amplifier link budgets
• Amplifier cascade limitations
• Environmental factors
• Drop length
• Minimum levels of the signal to the house
• Price
With the information provided, an ICT distribution designer should be able to decide the
types and sizes of cable that will work best with the network.
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables By fire Safety Properties
The telecommunications cable sheaths for indoor applications shall be specified with regard
to the fire safety requirements of the environment of where they are being installed.
The fire safety specifications shall be classified according to the various regional standards
(see Table 6.7).
Table 6.7
Examples of regional fire safety standards
Fire Safety Standard
Region
TEC 332 series
(international standard)
CSA FT series
(Canada)
DIN VDE 0472 series
(Germany)
JIS C-3521
(Japan)
ICEA T29-520
(United States)
IEEE 45, 383, 1202
(United States)
NFPA 70 (NEC)
(United States)
UL444, 1685, 1072, 1277, 1581,910
(United States)
CSA =Canadian Standards Association
DIN= Deutsches Institut fur Normung (German Institute for Standardization)
ICEA =Insulated Cable Engineers Association, Inc.
IEC =International Electrotechnical Commission
IEEE= Institute of Electrical and Electronics Engineers, Inc.
JIS =Japanese Industrial Standards
NEC = National Electrical Code
NFPA = National Fire Protection Association
UL = Underwriters Laboratories Inc.
VDE = Verband der Elektrotechnik Elektronik Informationstechnik (Association for Electrical,
Electronic, and Information Technologies)
Classifications by the IEC, NFPA, and CSA are the most widespread. NFPA's NEC17)
classification system is the most complicated and detailed.
According to NEC requirements, communications cables and wires shall be designed for the
indoor installations in buildings and comply with the class systems given in Table 6.8 and
Table 6.9.
The term plenum is applied to define the areas throughout the building, compartment, or
chamber to which one or more air ducts are connected, forming part of the air distribution
system. Such areas are the most dangerous in terms of fire safety because in case of fire, they
facilitate fast distribution of the flame and combustion products (smoke and gases) throughout
the building.
The term riser is applied to deflne, as a rule, any vertical service ducts (shafts and chambers)
and the interfloor passages of the building subject to the cable installation.
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables By Fire Safety Properties, continued
Table 6.8
Communications cable types
Marking
Cable Type
CMP
Communications plenum cable
CMR
Communications riser cable
CMG
Communications general-purpose cable
CM
Communications general-purpose cable
CMX
Communications cable, limited use
CMUC
Undercarpet communications wire and cable
-LP
Limited power
Type CMP
Type CMP communications plenum cables shall be listed as being suitable for use in ducts,
plenums, and other spaces used for environmental air and shall be listed as having adequate
fire-resistant and low smoke-producing characteristics.
Type CMR
Type CMR communications riser cables shall be listed as being suitable for use in a vertical
run in a shaft when penetrating one or more floors and shall be listed as having fire-resistant
characteristics and thus be capable of preventing the carrying of fire from floor to floor.
Type CMG
Type CMG general-purpose communications cables shall be listed as being suitable for
general-purpose communications use, with the exception of risers and plenums, and shall be
listed as being resistant to the spread of fire.
Type CM
Type CM communications cables shall be listed as being suitable for general-purpose
communications use, with the exception of risers and plenums, and shall be listed as being
resistant to the spread of fire.
Type CMX
Type CMX limited-use communications cables shall be listed as being suitable for use in
dwellings and raceways and shall be listed as being resistant to flame spread.
Type CMUC Undercarpet Wires and Cables
Type CMUC undercarpet communications wires and cables shall be listed as being suitable
for undercarpet use and shall be listed as being resistant to flame spread.
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables By Fire Safety Properties, continued
Type -lP
Type -LP may follow the designations previously listed and applies to cables suitable for use
in high density PoE applications.
Table 6.9
Optical fiber cable types
Cable Type
Suitability
OFNP
Nonconductive optical fiber plenum cable
OFCP
Conductive optical fiber plenum cable
OFNR
Nonconductive optical fiber riser cable
OFCR
Conductive optical fiber riser cable
OFNG
Nonconductive optical fiber general-purpose cable
OFCG
Conductive optical fiber general-purpose cable
OFN
Nonconductive optical fiber general-purpose cable
OFC
Conductive optical fiber general-purpose cable
Types OFNP and OFCP
Types OFNP and OFCP nonconductive and conductive optical fiber plenum cables shall be
listed as being suitable for use in ducts, plenums, and other space used for environmental air
and shall be listed as having adequate fire-resistant and low smoke-producing characteristics.
Types OFNR and OFCR
Types OFNR and OFCR nonconductive and conductive optical fiber riser cables shall be
listed as being suitable for use in a vertical run in a shaft when penetrating one or more
floors and shall be listed as having the fire-resistant characteristics capable of preventing the
carrying of fire from floor to floor.
Types OFNG and OFCG
'T'ypes OFNG and OFCG nonconductive and conductive general-purpose optical fiber cables
shall be listed as being suitable for general-purpose use, with the exception of risers and
plenums, and shall be listed as being resistant to the spread of fire.
Types OFN and OFC
Types OFN and OFC nonconductive and conductive optical fiber cables shall be listed as
being suitable for general-purpose use, with the exception of risers, plenums, and other spaces
used for environmental air, and shall be listed as being resistant to the spread of fire.
The information on the interaction of various classes within the system and their
interchangeability is shown in Figure 6.11. To preserve the integrity of the general
classification concept of the fire safety specifications, the illustrations show the class ranges
of the power, TV antenna, remote control, signaling, and fire alarm cables.
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables By fire Safety Properties, continued
Figure 6.11
ClassiAcation of cables and wires according to the NEC
NEC Article
725
770
Plenum
Riser
General
purpose
Dwellings
Cable A is allowed to be used in place of cable B
BL =
BM =
CATV=
CL2 =
CL3 ==
CM =
FPL =
NEC =
OFC =
OFN ==
PLTC =
Network-powered broadband communications low-power cables
Network-powered broadband communications medium-power cables
Community antenna TV cables
Remote-control, signaling, and power-limited cables, Class 2
Remote-control, signaling, and power-limited cables, Class 3
Communications cables
Power-limited fire alarm cables
National Electrical Code
Conductive optical fiber cables
Nonconductive optical fiber cables
Power-limited tray cables
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables By Fire Safety Properties, continued
International and European practices utilize only two classes of fire safety specifications:
• JEC 60332-1, Tests on electric and optical .fire cables underfire conditions- Testfor
verticalflame propagation /(;r a single insulated 1vire or cable, abbreviated 332-1.
• lEC 60332-3-24, Tests on electric and optical.fibre cables underfire conditions- Part 3-24:
Testfor verticalflame spread of vertically-mounted bunched wires or cables-Category C,
abbreviated 332-3c.
These specifications often are followed by the abbreviations LSOH or LSZH, defining
additional specifications of the cable sheaths and conductor insulations in terms of emission
of dangerous substances at burning (relevant testing standards IEC 60754, Test on gases
evolved during combustion ofmaterialsfi·om cables, and IEC 61034, Measurement of'smoke
density of cables burning under defined conditions - Part 1: Test apparatus).
See Table 6.10 for a comparison of the European and American classes.
Table 6.10
Interclass relativity of NEC and IEC fire safety specifications
Classification
NEC
IEC
Plenum
OFNP, OFCP, CMP
No equivalent
Riser
OFNR, OFCR, CMR
No equivalent
General purpose (U.S.)
OFNG, OFCG, OFN,
OFC,CMG,CM
fEC 60332.3c
General purpose (Europe)
No equivalent
TEC 60332.1
Dwellings
CMX
IEC 60332.1
LSOH (low smoke zero halogen)
No equivalent
IEC 60754
CM =Communications general-purpose cable
CMG =Communications general-purpose cable
CMP =Communications plenum cable
CMR =Communications riser cable
CMX =Communications cable, limited use
IEC =International Electrotechnical Commission
NEC = National Electrical Code
OFC =Conductive optical fiber general-purpose cable
OFCG =Conductive optical fiber general-purpose cable
OFCP =Conductive optical fiber plenum cable
OFCR =Conductive optical fiber riser cable
OFN = Nonconductive optical fiber general-purpose cable
OFNG = Nonconductive optical fiber general-purpose cable
OFNP = Nonconductive optical fiber plenum cable
OFNR = Nonconductive optical fiber riser cable
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Chapter 6: ICT Cables and Connecting Hardware
Classification of Cables By fire Safety Properties, continued
A direct comparison between NEC CM ratings and CSA FT (Canada) requirements is not
completely correct (see Table 6.11 ). CM ratings define cable fire properties, which shall
be tested per one ofthe UU' test standards, while FT is the name of the CSA test standard.
Generally speaking, if a CMR (or CM) UL FT-4 ULc marking is on a cable jacket, the cable
has a CMiCMR rating established by the NEC after being tested per the UL-1581 standard
and passing the FT-4 vertical tray test.
Table 6.11
Comparison between NEC CM ratings and CSA FT requirements
Fire Resistance Level
Test Requirements
NEC
Plenum
NFPA 262 (Steiner tunnel)
CSA-FT6 (Steiner tunnel)
OFNP, OFCP, CMP
UL-1666 (vertical shaft)
CSA-FT4 (vertical shaft)
OFNR, OFCR, CMR
Riser
General purpose
UL-1581 (vertical tray)
CSA-FT4 (vertical tray)
Dwellings
UL-1581 VW-1
CSA-FT
CMX
CM
CMG
CMP
CMR
CMX
CSA
NEC
NFPA
OFC
OFCG
OFCP
OFCR
OFN
OFNG
OFNP
OFNR
UL
TDMM, 14th edition
==
==
=
==
==
=
==
==
=
==
==
==
==
==
==
==
==
OFNG, OFCG, OFN, OFC,
CMG,CM
Communications general-purpose cable
Communications general-purpose cable
Communications plenum cable
Communications riser cable
Communications cable, limited use
Canadian Standards Association
National Electrical Code
National Are Protection Association
Conductive optical fiber general-purpose cable
Conductive optical fiber general-purpose cable
Conductive optical fiber plenum cable
Conductive optical fiber riser cable
Nonconductive optical fiber general-purpose cable
Nonconductive optical fiber general-purpose cable
Nonconductive optical fiber plenum cable
Nonconductive optical fiber riser cable
Underwriters Laboratories, Inc.
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Chapter 6: ICT Cables and Connecting Hardware
Balanced Twisted-Pair Connectors
Insulation Displacement Contact (IDC) Connectors-Overview
lDC is a gas-tight physical contact between two electrical conductors. IDCs feature blade or
knife shape cuts into the conductors' surrounding insulation material. During the conductor
termination, the IDC dovetail blades displace conductor insulation, reaching the conductor
and cutting into it. IDC connections typically require a special tool commonly known as a
punch-down tool.
The gas-tight contact is established by a cold weld and elimination of the air gap between
the conductor and the lDC and, therefore, the possibility of contact interface corrosion.
Such contact creates a reliable, long-lasting connection with stable electrical properties.
IDC connectors also eliminate conductor preparation (e.g., insulation removal), reducing the
tennination time and the number of tools.
Four basic styles of !DC connectors are defined by their design and IDC implementation:
• II 0-style
• 66-style
• BIX-style
• LSA-style
All other connectors are modifications or combinations of these four styles.
110-Style Insulation Displacement Contact (IDC) Connector
The 11 0-style is the most popular style of IDC connectors because of its compact design,
reliability, high transmission performance capabilities, and relatively inexpensive cost
to manufacture. It consists of an IDC dovetail and a base, which is usually either pressfit or soldered to a PCB as part of such cabling components as patch panels and some
telecommunications outlets/connectors. The 11 0-style IDC connector may be fixed in a
plastic housing that forms a connecting block, which also can be used with a PCB or as a
replaceable connector for 11 0-style wiring blocks.
Design
The II 0-style connectors consist of an IDC dovetail and a base. In Figure 6.12, contact and
conductor proportions are changed for the sake of illustration comprehensibility. Materials
used include phosphor bronze alloys plated with tin alloys. The 11 0-style connectors can
serve as the base for unscreened and screened connecting hardware.
Termination of conductors in the 11 0-style connector is performed by a single-pair or
multi pair punch-down tool. The 11 0-style connectors are designed for termination of
solid metal conductors (mostly made of copper) sized 22 AWG to 26 AWG. The 11 0-style
connector is capable of at least 200 termination cycles without degrading its reliability. There
are also some versions capable ofterminating both solid and stranded conductors. None of
the standard 11 0-style contacts allow termination of more than one conductor in the same
contact.
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Chapter 6: ICT Cables and Connecting Hardware
110-Style Insulation Displacement Contact (IDC) Connector, continued
Figure 6.12
110-style IDC connector design
B
A
A=
B=
C=
IDC =
MC =
TI =
IDC designed for mounting on a printed circuit board
110 connecting block IDC
Conductor termination in IDC
Insulation displacement contact dovetail
Metallic conductor
Thermoplastic insulation
Characteristics
The characteristics of a 11 0-style connector when used in structured cabling applications
should be subject to applicable telecommunications cabling component standards.
Table 6.12 offers an example of 11 0-style connector transmission performance capabilities.
NOTE: Connecting hardware consists of 11 0-style and modular connectors and shall be
characterized by a category of transmission performance as an assembly.
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Chapter 6: ICT Cables and Connecting Hardware
110-Style Insulation Displacement Contact (IDC) Connector, continued
Table 6.12
Connecting hardware transmission performance categories for 110-style connector-based connecting
hardware
ISO/IEC 11801-1
ANSI/TIA-568.2
110-Style Connector-Based
Connecting Hardware
Category 3 ( 1-16 Mllz)
Category 3 ( l-16 MHz)
Blocks, outlets, panels
Category 5 ( l-100 MHz)
Category 5e ( 1-l 00 MHz)
Blocks, outlets, panels
Category 6 ( 1-250 MHz)
Category 6 ( l-250 Mllz)
Blocks, outlets, panels
Category 6A ( 1-500 Mllz)
Category 6A ( l-500 MHz)
Outlets, panels
Category 7 ( 1-600 MHz)
N/A
N/A
Category 7A ( 1-1000 MHz)
N/A
N/A
Category 8 (2000 MHz)
Category 8 (2000 MHz)
Outlets
ANSI= American National Standards Institute
IEC =International Electrotechnical Commission
ISO= International Organization for Standardization
N/A =Not applicable
TIA =Telecommunications Industry Association
NOTE: For additional information on connecting hardware characteristics, refer to Chapter 1:
Principles ofTransmission.
Advantages and Disadvantages
The 11 0-style connector's advantages are:
• A high-quality, reliable, and durable electrical contact.
• High transmission performance characteristics.
• A simple, inexpensive design.
• A short termination time.
• Tt allows connections to be created in one-pair increments.
• It can be used in a number of different styles of connecting hardware.
• Patch cords used for cross-connections and interconnections to 110-style connectors can be
terminated in the field with 100-percent transmission-compliant 11 0-plugs.
• The conductor termination is performed with a widely available tool.
• lt is widely used by the industry.
The II 0-style connector's disadvantage is that it does not exist in screened versions as a
stand-alone connector.
© 2020 BICSI®
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Chapter 6: ICT Cables and Connecting Hardware
110-Style Insulation Displacement Contact (IDC) Connector, continued
Typical Applications
The 11 0-style connectors can be used in different kinds of connecting hardware and
applications, including:
• 11 0-style wiring block connectors.
• Modular patch panel connectors used for distribution cable conductor termination.
• Modular telecommunications outlets/connectors used for distribution cable conductor
terminations.
66-Style Insulation Displacement Contact (IDC) Connector
The 66-style, one of the oldest industry connectors, once dominated the market of
telecommunications and low-speed data communications applications. It was gradually
replaced by the more advanced II 0-style. Because of its high-density termination design
and simple and inexpensive manufacturing, the 66-style remained an alternative for
telecommunications applications.
The 66-style connector is designed so that the contact displaces the insulation to make contact
with the metallic conductor.
Design
'I'he 66-style connector consists of an IDC dovetail and a base (see Figure 6.13). Materials
used include phosphor bronze alloys plated with tin alloys. The 66-style connector does not
exist in screened versions.
Termination of conductors in the 66-style connector is performed by a single-position
punch-down tool. 66-style connectors are designed for termination of solid metal conductors
sized 22 AWG to 26 AWG. There are also some versions capable of terminating both solid
and stranded conductors. It is possible to terminate more than one conductor in the same 66
contact, but such practice is not recommended. Because of the overstress, the contact loses its
retention etliciency, and all consecutive terminations become less and less reliable.
66-style contacts are usually assembled in plastic housings to form 66-style connecting
blocks with various numbers of contacts (most popular are 25-, 50-, and 100-pair blocks)
and several 66-connector styles. Some of them have wire binding (i.e., wire wrap) tails to be
used in prewired blocks; others are manufactured in a twin 66-style single-piece connector
facilitating cross-connection by means of bridging clips and cross-connect wires.
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Chapter 6: ICT Cables and Connecting Hardware
66-Style Insulation Displacement Contact (IDC) Connector, continued
In Figure 6.13, contact and conductor proportions were changed for the sake of illustration
comprehensibility.
Figure 6.13
Examples of 66-style connector designs
Category 3 compliant
66-type connectors
Category Se compliant
66-type connectors
Difference between
category 3 and Se
66-type connectors
IDC == Insulation displacement contact dovetail
MC == Metal conductor
TI == Thermoplastic insulation
Characteristics
The characteristics of a 66-style connector when used in structured cabling applications
should be subject to telecommunications cabling component standards.
© 2020 BICSI®
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Chapter 6: ICT Cables and Connecting Hardware
66-Style Insulation Displacement Contact (IDC) Connector, continued
Table 6.13 offers an example of a 66-style connector's transmission performance capabilities.
NOTE: Category 3 or 5e compliant connector is not enough to define the resulting
transmission performance category of a particular design block. It depends both on
the 66-style connector used and the block's design.
Table 6.13
Connecting hardware transmission performance categories
ISO/IEC 11801-1
ANSI/TIA-568.2
66-Style Connector
Category 3 (1-16 MHz)
Category 3 ( 1-16 MHz)
Certain designs
Category 5 (1-100 MHz)
Category 5e ( 1-100 MHz)
Certain designs
Category 6 ( 1-250 MHz)
Category 6 ( 1-250 MHz)
N/A
Category 6A (1-500 MHz)
Category 6A ( 1-500 MHz)
N/A
Category 7 (l-600 MHz)
N/A
N/A
Category 7A (1-1 000 MHz)
N/A
N/A
Category 8 (2000 MHz)
Category 8 (2000 MHz)
N/A
ANSI=
IEC =
ISO=
N/ A=
TIA =
American National Standards Institute
International Electrotechnical Commission
International Organization for Standardization
Not applicable
Telecommunications Industry Association
NOTE: Additional information on connecting hardware characteristics can be found in
Chapter I: Principles of Transmission.
Advantages and Disadvantages
66-style connector's advantages are:
• A comparatively reliable and durable electrical contact.
• Comparatively good transmission performance characteristics.
• A simple, inexpensive design.
• Short termination time.
• It allows connections to be created in one-pair increments.
• A high density of terminations.
• A wide range of connector configurations-straight-thru, bridging, splitting, and prewired.
• The conductor termination is performed with a widely available tool.
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Chapter 6: ICT Cables and Connecting Hardware
66-Style Insulation Displacement Contact (IDC) Connector, continued
66-style connector's disadvantages are:
• It does not exist in screened versions as a stand-alone connector.
• It covers a comparatively narrow range of transmission performance categories (e.g., voice
grade circuits).
• It can exist only in the form of a 66-style connecting block.
• A limited number of applications.
Typical Applications
Because of its specific design, a 66-style connector can be used only in the form of the
66-style connecting block and support a limited number of telecommunications applications,
including:
• Demarcation point connecting hardware.
• Platform for circuit protection.
• Compact cross-connections and interconnections in voice and data applications.
• Metal conductor splicing.
SIX-Style Insulation Displacement Contact (IDC) Connector
The BIX -style contacts evolved in the 1970s and became a popular choice for voice and data
networks.
Design
The BIX-style connector consists of an IDC dovetail and a base (see Figure 6.14). Materials
used include phosphor bronze alloys plated with tin alloys.
BIX-style connectors can serve as the base for unscreened and screened connecting hardware.
Termination of conductors in the BlX-style connector is performed by means of a singleposition punch-down tool.
BIX-style connectors are designed for termination of solid metal conductors sized 22 AWG
to 26 AWG. None of the standard BIX-style contacts allow termination of more than one
conductor in the same contact. 'T'he BIX-style connector is capable of at least 200 termination
cycles without degrading its reliability.
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Chapter 6: ICT Cables and Connecting Hardware
BIX-Style Insulation Displacement Contact (IDC) Connector, continued
Figure 6.14
BIX-style IDC connector design
IDC
MC
TI
IDC = Insulation displacement contact dovetail
MC = Metal conductor
TI = Thermoplastic insulation
Characteristics
The characteristics of a B IX-style connector when used in structured cabling applications
should be subject to telecommunications cabling component standards.
Table 6.14 offers an example of a BlX-style connector's transmission performance
capabilities.
Table 6.14
Connecting hardware transmission performance categories for SIX-style connectors
ISO/IEC 11801-1
ANSI/TIA-568.2
BIX-Style ConnectorBased Connecting
Hardware
Class C (1-16 MHz)
Category 3 (1-16 MHz)
Blocks, outlets, panels
Class D (1-100 MHz)
Category 5e (1-100 MHz)
Blocks, outlets, panels
Class E ( l-250 MHz)
Category 6 ( 1-250 MHz)
Blocks, outlets, panels
Class E11 (1-500 MHz)
Category 6A ( l-500 MHz)
Outlets, panels
Class F (1-600 MHz)
N/A
N/A
Class F11 (l-1000 MHz)
N/A
N/A
ANSI
IEC
ISO
N/ A
TIA
TDMM, 14th edition
=American National Standards Institute
=International Electrotechnical Commission
=International Organization for Standardization
= Not applicable
=Telecommunications Industry Association
6-40
© 2020 BICSI®
Chapter 6: ICT Cables and Connecting Hardware
BIX-Style Insulation Displacement Contact (IDC) Connector, continued
NOTE: For additional information on connecting hardware characteristics, refer to Chapter I:
Principles ofTransmission.
Advantages and Disadvantages
B IX -style connector's advantages are:
• A high-quality, reliable, and durable electrical contact.
• High transmission performance characteristics.
• A simple, inexpensive design.
• Short termination time.
• It allows connections to be created in one-pair increments.
• A wide range of connector configurations-straight-thru, bridging, splitting, and prewired.
• It can be used in a number of different styles of connecting hardware.
• Patch cords used for cross-connections and interconnections to BIX-style connectors can be
terminated in the field with 100 percent transmission compliant BIX-plugs.
• High density of terminations.
BIX-style connector's disadvantages are:
• lt is not widely used by the industry.
• The conductor termination is performed with a special tool.
• It is nonexistent in screened versions as a stand-alone connector.
Typical Applications
BIX-style connector's typical applications are:
• BIX distribution and multiplying connectors and frames.
• Modular patch panel connectors used for distribution cable conductors termination.
• Modular telecommunications outlets/connectors used for distribution cable conductors
termination.
• Platform for circuit protection.
lSA-Style Insulation Displacement Contact (IDC) Connector
The term LSA is derived from the first letters of the German words l6tfrei, schraubfrei,
and abisolierfrei (i.e., no solder, no use of screws, no insulation removal). The LSA-style
connector has become a popular choice for voice and data networks because of its unique
quality, transmission performance capabilities, and ultimate termination density.
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Chapter 6: ICT Cables and Connecting Hardware
LSA-Style Insulation Displacement Contact (IDC) Connector, continued
Design
An LSA-style connector consists of an IDC dovetail and a base (see Figure 6.15). Materials
used are typically phosphor bronze alloys plated with silver (original design) or tin alloys
(clones).
During the termination process, the terminated conductor is pressed into the contact slot
between the contact clips, which are placed at a 45-degree angle to the conductor. The contact
clips move toward the conductor twisting at the same time, pierce the insulation, and enter
the conductor. The twisting of the contact clips along with pressure creates reliable, gastight
contact.
LSA-style connectors can serve as the base for unscreened and screened connecting
hardware.
LSA-style connectors are designed for termination of solid metal conductors sized 22 AWG
to 26 AWG. Termination of conductors in the LSA-style connector is performed by a singleposition punch-down tool.
Figure 6.15
Examples of LSA-style connector designs
MC
A
IDC
c
A=
B=
C=
IDC =
MC =
TI =
Connection contact
Disconnection contact
Switching contact
Insulation displacement contact
Metallic conductor
Thermoplastic insulation
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Chapter 6: ICT Cables and Connecting Hardware
LSA-Style Insulation Displacement Contact (IDC) Connector, continued
Characteristics
The characteristics of an LSA-style connector when used in structured cabling applications
are subject to telecommunications cabling component standards.
Table 6.15 offers an example of LSA-style connector transmission perfom1ance capabilities.
Table 6.15
Connecting hardware transmission performance categories for LSA-style connector-based connecting
hardware
ISO/IEC 11801-1
ANSI/TIA-568.2
LSA-Style ConnectorBased Connecting
Hardware
Class C (1-16 MHz)
Category 3 ( 1-16 MHz)
Blocks, outlets, panels
Class D (1-100 MHz)
Category 5e ( 1-100 MHz)
Blocks, outlets, panels
Class E ( 1-250 MHz)
Category 6 ( 1-250 MHz)
Blocks, outlets, panels
Class EA (1-500 MHz)
Category 6A ( 1-500 MHz)
Outlets, panels
Class F ( 1-600 MHz)
N/A
N/A
Class FA ( 1-1 000 MHz)
N/A
N/A
ANSI
IEC
ISO
N/A
TIA
= American National Standards Institute
=
=
=
=
International Electrotechnical Commission
International Organization for Standardization
Not applicable
Telecommunications Industry Association
NOTE: For additional information on connecting hardware characteristics, refer to Chapter I:
Principles ofTransmission.
Advantages and Disadvantages
LSA-style connector's advantages are:
• A high-quality, reliable, and durable electrical contact.
• High transmission performance characteristics.
• A short termination time.
• It allows connections to be created in one-pair increments.
• It can be used in a number of different styles of connecting hardware.
• A high density of terminations.
• A wide range of connector configurations-connection, disconnection, and switching.
LSA-style connector disadvantages:
• Comparatively complex and expensive design.
• Conductor termination is performed with a special tool, which is not always available.
• Not widely used by the data communications industry.
© 2020 BICSI®
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Chapter 6: ICT Cables and Connecting Hardware
LSA-Style Insulation Displacement Contact (IDC) Connector, continued
Typical Applications
LSA-style connector's typical applications are:
• LSA-style connector blocks.
• Platfonns for integrated circuit protection.
• Modular patch panel connectors used for distribution cable conductors termination.
• Modular telecommunications outlets/connectors used for distribution cable conductors
termination.
Modular Connectors
Modular connectors are represented by two heterogeneous parts-plug (male connector part)
and jack (female connector part). Plugs