May 2006
doc.: IEEE 802.19-06/0025r0
IEEE P802.19
Wireless Coexistence
May 2006 Minutes
Date: 2006-05-19
Author(s):
Name
Stephen R Whitesell
Company
VTech
Communications
Address
2 Shannon Ct
Howell, NJ 07731
Phone
732 751 1079
Email
swhitesell@vtech.ca
Abstract
This document provides a record of the minutes for the May 2006 meeting of the IEEE 802.19
Coexistence Technical Advisory Group.
Notice: This document has been prepared to assist IEEE 802.19. It is offered as a basis for discussion and is not binding on the
contributing individual(s) or organization(s). The material in this document is subject to change in form and content after
further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution,
and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE
Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit
others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and
accepts that this contribution may be made public by IEEE 802.19.
Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http://
ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s),
including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents
essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the TAG of patent
information that might be relevant to the standard is essential to reduce the possibility for delays in the development process
and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair
<Shellhammer@ieee.org> as early as possible, in written or electronic form, if patented technology (or technology under patent
application) might be incorporated into a draft standard being developed within the IEEE 802.19 TAG. If you have questions,
contact the IEEE Patent Committee Administrator at <patcom@ieee.org>.
Submission
page 1
Steve Whitesell, VTech
May 2006
doc.: IEEE 802.19-06/0025r0
The IEEE 802.19 Coexistence Technical Advisory Group (TAG) met in conjunction with the IEEE 802
Wireless Interim session in Jacksonville, FL during the week of May 15-19, 2006. Minutes for each of
the meetings held during the week are provided below.
Tuesday AM 1
Chair Steve Shellhammer called the meeting to order at 8:11 am. The agenda as given in 19-06-0020-010000 (06/0020r1) was reviewed and approved as submitted. Steve noted the need to be flexible in the
timing for Item 10 dealing with our comments on the 802.11n CA document 11-06/338r3, which is
scheduled for the PM1 time slot. The 802.11n CA folks plan to join us to discuss their proposed
comment resolutions. He also noted that no contributions have been received on the call for papers for
the Recommend Practice document.
Steve S then reviewed the IEEE-SA Patent Policy and list of inappropriate topics for discussion at
meetings as given in 06/0017r0.
Steve Whitesell reviewed three documents related to minutes for the March session. Document
06/0013r0 covers the joint 802.19/P1900 meeting. A couple of typos were noted and fixed in 06/0013r1,
which was approved as amended. The minutes of the 802.19 TAG meetings were provided in 06/0015r0.
John Barr asked that his attendance during the Wednesday AM2 time slot be noted, so the included
attendance chart was modified as requested. The revised minutes were accepted as modified and will be
posted as 06/0015r1. Finally, the SG1 minutes in 06/0014r0 were reviewed and accepted as presented.
Steve S has created 06/0023r0 as a first draft of the procedure the TAG will follow for development of the
Recommended Practice. He indicated he would make changes to the document as we reviewed it and
repost it as 06/0023r1. The introduction includes references to PAR and Call for Submissions documents.
Initial presentations will be made during 802.19 TAG sessions in the following three categories:



Coexistence scenarios
Coexistence metrics
Methods for evaluating coexistence methods
Feedback will be provided to presenters based on straw poll of 802.19 participants as to whether TAG
members support continuing to the next step. Tom Siep noted document is meant to be a toolkit.
Multiple contributions can be accepted. A down-select vote is not expected since multiple coexistence
scenarios, metrics, and evaluation methods will be included in the Recommended Practice, but documents
could be rejected based on lack of merit. John Barr indicated we might need some general evaluation
criteria such as requiring presentations to have a statement as to how they fit the scope of the
Recommended Practice. Presenters who are encouraged to continue will be asked to make a follow-up
technical contribution properly formatted.
John Barr suggested we need some way of vetting validity of methods. The methodologies in the
Recommended Practice could be used as part of a downselect process for showing one proposal has better
coexistence than another. Steve S indicated we will need to make sure liaisons get good review of draft in
their respective wireless groups at time of ballot in order to address this issue.
Technical specification submissions should include a detailed description of the text intended to be
included in Recommended Practice. The TAG will also accept contributions of general text sections. All
technical specification and general text submissions need to conform to formatting specifications in
06/0019r0. Barr suggests presentation should be made to relevant WGs and get their positive feedback
that proposal is valid. We also may need to seek feedback from outside groups (P1900, Wi-Fi Alliance,
Wi-Max, etc.). The TAG will vote on acceptance of individual contributions into the working document.
The vote is technical and requires 75% approval to pass. Changes to the working document, once text is
accepted into it, also require a 75% vote. The vote will be held at a plenary or at an interim if a quorum is
Submission
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Steve Whitesell, VTech
May 2006
doc.: IEEE 802.19-06/0025r0
present. When the working document is complete, it will be given final edit, turned into an official draft,
and sent out for letter ballot.
Three 802.11n participants joined the meeting at 9:10 am to discuss their ballot resolution document 1106/0541r6 as it applies to comments submitted by the TAG. Sheung Li led the discussion with input from
Eldad Perahia and Darren McNamara. They are proposing to reject our suggestion to redo simulations at
10% BER based on (1) their desire for quantifying the conditions for an interference-free link as
represented by 1% BER and (2) their assessment that it wouldn’t make that much difference in needed
separation distance.
There was also discussion about the temporal Bluetooth® model. The one chosen is always on for all
time slots or off for all time slots. Steve S has questioned if this is too conservative. He will do more
analysis with his approach and provide it to 11n.
The meeting was recessed at 9:54 am for a short break.
Tuesday AM 2
Chair Steve Shellhammer re-convened the meeting at 10:15 am.
Sheung Li resumed the discussion of proposed resolution of TAG comments on the 802.11n CA
document. Darren pointed out that aggregate packet lengths of 40 kbytes, as shown in the document
graph, would be very rare. Something more like 10 or 15 kbyte aggregates would be a more realistic
upper limit, particularly in an interfering environment. At 15 kbytes of aggregation, throughput drops
about 50% with 100% Bluetooth occupancy. Clarifying text will be added to the CA document about
implementation specific approaches for dealing with aggregation, etc.
In regard to the comments concerning cordless telephone interference, the 802.11n CA document is
relying on the information in 05/0026r0, which they identify as reference [11]. If we update that
document to provide more typical FHSS characteristics and add DSSS characteristics, 11n will consider
using them in their analysis.
Steve S resumed discussion of procedure document 06/0023r0. He briefly summarized the earlier
discussion for new participants in the AM2 session. After the working document is complete, the TAG
will vote to send draft out for Letter Ballot. The draft must be complete and meet 802 P&P criteria for
going to ballot. Liaisons will be asked to compile comments from the groups they represent.
A discussion about the schedule and timeline for presenters ensued. To maintain flexibility, the only
requirement for initial presentations is that they be available on the server prior to being given.
Contributions of technical specifications submitted for a vote into the working document need to be
submitted by the Wednesday prior to the meeting unless an exception has been granted by the chair. The
section on schedule was deleted. The intent is to vote on this document at July Plenary.
The meeting was recessed at 11:58 am with a plan to resume at 1:00 pm.
Tuesday PM 1
Chair Steve Shellhammer re-convened the meeting at 1:18 pm.
Steve S presented 06/0019r0 that had been prepared by editor David Cyher to provide guidance on format
for the technical contributions to the Recommended Practice. The TAG members present had questions
about the request for providing the data points for plotting graphs. How are the data points to be
provided? In an Excel spreadsheet, a text document with comma separated values (csv), or by some other
Submission
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Steve Whitesell, VTech
May 2006
doc.: IEEE 802.19-06/0025r0
means? There was also a question concerning whether the statement about providing a source file for
vector graphics implies that original Visio files should be provided if a drawing is created in Visio.
Steve S presented 06/0024r0 to stimulate discussion on coexistence scenarios. It provides some basic
scenarios to consider as a starting point. He created 06/0024r1 to capture changes as we discussed the
document. We have discussed the first two scenarios previously. One involves two frequency static
networks with interference dominated by close proximity of one device from each network. The second
scenario is similar, but with one of the frequency static networks replace with an FHSS network such as
Bluetooth. A third scenario involves Dynamic Frequency Selection (DFS). It assumes a primary user in
part of the band and products that sense the existence of the primary user and move to another frequency.
DFS is based on detection of signals above predetermined level and has time considerations as well.
Steve S also discussed a fourth scenario using Clear Channel Assessment. In this scenario, two
unlicensed networks share a frequency band and assess whether a channel is in use before transmitting.
Tom S talked about a UWB model using distributed control systems wherein timeslots are allocated but a
beacon is shared. This tends to create a problem because the beacon prohibits individual systems that
could communicate from doing so.
Steve S encouraged people to make contributions for July, especially contributions concerning
coexistence scenarios.
The meeting was recessed at 2:10 pm.
Tuesday PM 2
The TAG did not meet during this time slot due to lack of contributions for consideration.
Wednesday AM 1
Chair Steve Shellhammer re-convened the meeting at 8:05 am. Patrick Kinney, Raine Hack and Kyung
Kuk Lee of 802.15.4a joined the meeting to disscuss TAG comments on their CA documents, 1506/214r0 for the CSS PHY and 15-06/215r0 for the UWB PHY. Patrick gave an overview of how
802.15.4a devices work: very low throughput, low overhead. The 15.4a devices are similar to 15.4
devices in their applicability. The main differences are location awareness, robustness, enhanced range,
and mobility. UWB is well suited to location awareness. CSS is well suited to robustness and enhanced
range. Both PHYs support higher data rates than 15.4 (1 Mbps for CSS and 27 Mbps for UWB), but
throughput remains quite low (how often do you read a meter?).
Patrick then addressed the 15.4a LB 34 comments from the TAG as given in 15-06/0240r2. The two
separate CA documents will be combined into one and included as an annex to the standard. They are not
planning to address coexistence with TV band operation where their operating frequencies overlap
because they are compliant with FCC Part 15, Subpart B and Subpart F rules. They will do some analysis
of coexistence with ECMA-0368 in the 3-10 GHz UWB band, but it will be more based on broad analysis
of characteristics rather than any detailed modelling. They proposed to accept most comments related to
adding missing information (802.11g, 802.16, etc.). The TAG comment about assumed duty cycle and
packet length is being rejected because it is covered by a statement that a 100% duty cycle is assumed for
other standards. However, they are rethinking this and may do some anaqlyses with less than 100 % duty
cycle
The TAG Comment about assumed the 1% duty cycle for 15.4a devices is proposed to be rejected.
Discussion indicated the TAG has no issue with 1% but asks if could it be higher for short periods. Ivan
Reede indicated he is aware of products that could transmit continuously for 35 seconds once in a onehour period. The TAG asked that the CA document mention such cases if known. The 15.4
representatives also agreed to include a 10% duty cycle for a limited period of time.
Submission
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Steve Whitesell, VTech
May 2006
doc.: IEEE 802.19-06/0025r0
The TAG comment about providing analysis for co-channel interference for 11b and 11g was then
discussed. TAG members described common scenarios where co-channel operation might not be
avoidable. Housing developments and apartment complexes were cited as examples where several
802.11 WLANs might be in operation covering the entire 2.4 GHz band. They will add some analysis
showing 15.4a interferes for only a very short duration. The TAG comment about Bluetooth can be dealt
with by analogy to coexistence of two fast frequency hoppers (the 15.4a CSS sweep is a hop in a
prescribed sequence).
Patrick then indicated he has taken on a role dealing with coexistence for standards developed by ISA –
the Instrument, Systems, and Automation Society. He asked how to go about establishing a liaison with
802.19 TAG. Steve S suggested he send an email request and perhaps plan to do a presentation at the
next meeting.
The meeting was adjourned for the week at 9:57 am.
Attendance
The following individuals were in attendance for the 802.19 TAG meeting time slots shown:
Participant
Mark Austin
John Barr
Raine Hack
Patrick Kinney
Kyung Kuk Lee
Joseph Levy
Sheung Li
Peijuan Liu
Dan Lubar
Darren McNamara
Eldad Perahia
Ivan Reede
Steve Shellhammer
Tom Siep
Steve Whitesell
Submission
Tue
AM1
X
X
Tue
AM2
X
X
Tue
PM1
X
Wed
AM1
X
X
X
X
X
X
X
X
X
X
X
X
X
page 5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Steve Whitesell, VTech
May 2006
doc.: IEEE 802.19-06/0025r0
References:
11-06/0383r3 – 802.11n Coexistence Assurance Document, Perahia and Li
11-06/0541r6 – 802.11n LB84 Comment Resolution Summary, Stephens
15-06/0214r0 – Coexistence Assurance Information for the CSS Part of 15.4a, Hach and Lee
15-06/0215r0 – TG4b UWB Coexistence Assurance, Welborn
15-06/0240r2 – LB 34 Comment Resolution
19-05/0026r0 – Cordless Telephone Coexistence Considerations, Whitesell
19-06/0013r1 – March 2006 Minutes of Joint Meeting with P1900, Whitesell
19-06/0014r0 – March 2006 Minutes for SG1, Whitesell
19-06/0015r1 – March 2006 Minutes for 802.19, Whitesell
19-06/0017r0 – IEEE IPR Policy, Shellhammer
19-06/0019r0 – Special Formatting Instructions for Draft Content, Cypher
19-06/0020r1 – May 2006 Agenda, Shellhammer
19-06/0023r1 – Procedure for the Development of the Recommended Practice, Shellhammer
19-06/0024r1 – Discussion of Coexistence Scenarios, Shellhammer
Submission
page 6
Steve Whitesell, VTech