REV
1
2
3
4
5
Description of Change
REVISION HISTORY
Author
Rev.1 Philip Palmeri
Rev.2
Rev.3
Rev.4
Rev.5
Piyush Raj
Stephen Turner
Stephen Turner
Taha S. Yaseen
Effective Date
05/10/2013
06/21/2013
02/13/2014
04/16/2014
11/26/2014

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
2 of 12
1 Coax Segment Sweep Testing – Return Loss & DTF Return Loss .................................................................................... 3
1.1 Introduction to Test .................................................................................................................................................... 3
1.2 Required Tools & Equipment ...................................................................................................................................... 3
1.3 Equipment Setup......................................................................................................................................................... 3
1.4 Operational Procedures .............................................................................................................................................. 4
1.5 Segment Sweep Return Loss & DTF Return Loss Passing Requirements .................................................................... 5
1.6 Labeling and Documentation ...................................................................................................................................... 7
1.7 Submittal Process ........................................................................................................................................................ 7
2 DTF Return Loss – System Sweep Test ........................................................................................................................ 8
2.1 Introduction to Test .................................................................................................................................................... 8
2.2 Required Tools/Equipment ......................................................................................................................................... 8
2.3 Equipment Setup......................................................................................................................................................... 8
2.4 Operational Procedures .............................................................................................................................................. 9
2.5 System Sweep Return Loss & DTF Return Loss Passing Requirements .................................................................... 10
2.6 Labeling and Documentation .................................................................................................................................... 11
2.7 Submittal Process ...................................................................................................................................................... 12
3 Appendix ....................................................................................................................................................................... 12
3.1 Cabling Diagram Sample: .......................................................................................................................................... 12
3.2 ATC Installation Workbook Sample: ......................................................................................................................... 12

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
3 of 12
It is an American Tower requirement that each segment of coaxial cable be tested to measure Return Loss (RL) &
Distance-To-Fault Return Loss (DTF-RL) to a 50 ohm load. The purpose of this section is to assure that coax sweep testing is performed and documented per ATC standards. This section assumes the reader has a technical understanding of RF tools, testing, and is sweep certified on the device used to test.
This test will assure that each coax cable has no faults and the connectors are properly terminated. This test must be performed on each individual coax cable at:


Remote Unit side (remote out to the associated antennas).
Head End side (Demarcation Board to Attenuation Trays) and (Attenuation Trays to POIs).
Note:
If Head End coax cables are factory tested then NO segment sweep is required and factory test results would be enough.

Anritsu S332E Spectrum Analyzer

Anritsu Line Sweep Tools Software

Phase Stable cable

Calibration Kit

Precision 50 Ohm Load

Coax data sheet

Adapter Set: 7/16 (M) - N-Type (M) & 7/16 (F) - N-Type (M)

Valid Anritsu Calibration Certificate

Line Sweep Certification Class – Certificate of Completion
Turn the spectrum analyzer on and allow 30 minutes to warm up to adjust the unit’s temperature. Utilizing the dual format display function, place the spectrum analyzer in return loss & DTF return Loss mode. For return loss, the amplitude (Y-axis) should be setup to view from 0.0dB to 50.0dB. For DTF return loss, the distance (x-axis) should be
25% longer than the coax line under test.

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
4 of 12
Example: DTF Return Loss Total Distance Calculation
I.
100 ft. distance of coax run under test
II.
Distance scaling = Distance of coax run under test + 25%
= 100 ft. + 25ft.
= 125 ft.
 Start distance = 0 ft.

Stop distance = 125 ft.
Select the appropriate cable type from the DTF parameters menu. All settings must match the cable spec sheet (prop velocity, insertion loss, etc.). Set the limit line to 18.0 dB for return loss only (DTF - RL display will be used to identify the problematic spots only and no limit line is required).
ATC requires coax must be swept on 3 separate tests as below:



First one: at a frequency range of (698 - 960MHz) low band.
Second one: at a frequency range of (1700 - 2000MHz) mid band.
Third one: at a frequency range of (2100 – 2400MHz) high band.
Once the frequencies are selected, perform calibration of the spectrum analyzer as necessary. Perform a system calibration at a minimum of once every two hours.
Once the frequency is selected and spectrum analyzer is properly calibrated, connect the phase stable cable to the RF
Out port of the spectrum analyzer. Connect the other end of the phase stable cable directly to the coax line. Place the precision 50 Ohm Load on the opposing end of the coax line. Coax segment sweep test should not be performed through any jumper cables, splitters, or couplers in the DAS system but on an individual Coax segment only (see diagram below).

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
5 of 12
Utilizing the dual format display function of the spectrum analyzer, perform low, mid and high band return loss & DTF return loss segment sweep (Return loss and DTF return loss measurements are to be performed simultaneously) under the measurement menu function of the spectrum analyzer. Save the data in native (VNA) and screenshot in PDF format.
A.
Return loss measurements are to be lower than the limit line set at 18 dB utilizing the marker to peak function of the analyzer.
B.
DTF return loss events (spikes) between the spectrum analyzer RF out port and the 50 ohm load Must be lower than 40 dB else the coax segment will be considered as defective and a new coax run to be pulled instead.
If the coax or any connector fails to meet these specifications, troubleshoot and fix. Proper connector installation and coax cable bend radius is critical in receiving good test results for coax return loss.

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
6 of 12

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
7 of 12
The segment sweep plots should be labeled according to the following:
Site ID_Cable ID_RL_LB
Site ID_Cable ID_DTF - RL_LB
Site ID_Cable ID_RL_MB
Site ID_Cable ID_DTF - RL_MB
Site ID_Cable ID_RL_HB
Site ID_Cable ID_DTF - RL_HB
Note:

LB = Low Band 698-960MHz.

MB = Mid Band 1700-2000MHz.

HB = High Band 2100-2400MHz.

Cable ID = to be taken from the Antenna layout or the Schematic diagram (as shown in the Appendix cabling diagram).
Example
Site Code = 318497
Cable ID = CBL33
File Name  318497_CBL33_RL_LB
File Name  318497_CBL33_DTF - RL_LB
After all coax lines have been tested and all passing results are obtained, the results must be submitted to ATC
Construction Manager within 7 days before Final Punch walk. Include the VNA native files, PDF screenshots, and a summary Excel spreadsheet with the results. Include summaries for all tests in the ATC closeout summary as shown below. A Pass in the summary sheet indicates ALL low, mid and high band tests are 100% below the limit line.
Coax Cable ID
CBL 33
CBL 33
CBL 33
Segment Sweep Test - Return Loss / DTF Return Loss
Band
Low Band 698-960 MHz
Mid Band 1700-2000 MHz
High Band 2100-2400 MHz
Return Loss Measurement
(under 18.0dB)
18.2dBm
20.0dBm
24.3dBm
Remarks (Pass/Fail)
Pass
Pass
Pass

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
8 of 12
Once all the segment sweeps are complete ATC requires Distance-To-Fault Return Loss (DTF-RL) system sweeps to be performed from each DAS remote out to the associated antennas. This includes the whole feeders, jumpers and passive components.

Anritsu S332E Spectrum Analyzer

Anritsu Line Sweep Tools Software

Phase Stable cable

Calibration Kit

Calibrated open load

Coax and passive components data sheets

Adapter Set: 7/16 (M) - N-Type (M) & 7/16 (F) - N-Type (M)

Valid Anritsu Calibration Certificate

Line Sweep Certification Class – Certificate of Completion
Turn the spectrum analyzer on and allow 30 minutes to warm up to adjust the unit’s temperature. Place the spectrum analyzer in DTF return Loss mode. The distance (x-axis) should be 25% longer than the coax line to be tested but
(frequency resolution setting should not exceed 200 KHz and fault resolution shouldn’t exceed 2 - 4 feet). Select the appropriate cable type from the DTF parameters menu. All settings must match the cable spec sheet (prop velocity, insertion loss, etc.). Limit line to be set using the Calibrated Open Load (see operational procedure).
ATC requires coax must be swept on 3 separate tests as below:

First one: at a frequency range of (698 - 960MHz) low band.

Second one: at a frequency range of (1700 - 2000MHz) mid band.

Third one: at a frequency range of (2100 – 2400MHz) high band.
Once the frequencies are selected, perform calibration of the spectrum analyzer as necessary. Perform a system calibration at a minimum of once every two hours.

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
9 of 12
Disconnect cable at remote location connect to the
Anritsu for system sweeps on each of the MIMO paths
Disconnect any antenna and have the Calibrated
Open Load connected instead.
A.
All faults detected during the segment testing must have been repaired prior to performing the DTF return loss system test.
B.
All passive components (open ports) must be terminated with 50 ohm loads prior to performing the system sweep test.
C.
Disconnect any DAS antenna and have the Calibrated Open Load connected instead (repeat this step for each system sweep). The peak generated by the Calibrated Open Load will be the reference to Pass/Fail the results.
D.
Mark the peak generated by the Calibrated Open Load and set your limit line to its value.
Note:


Select an antenna location as near as possible to the Remote Unit to easily recognize the Calibrated Open Load peak and to avoid any confusion with other passive components peaks.
The peak height of the Calibrated Open Load will vary depends on how far is the selected antenna (being replaced by load) from the Remote Unit.

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
10 of 12
Reflection peak should be a PASS if minimum 6 dB to the open calibrated load is obtained (see example #3).
If the coax or any connector fails to meet these specifications, troubleshoot and fix. Proper connector installation and coax cable bend radius is critical in receiving good system sweep results
Calibrated Open
Load – Limit Line at 11 dB
Minimum of 6dB
(Peak to Limit Line) to PASS
Disconnect any antenna and have the Calibrated
Open Load connected instead.

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
Site ID_Remote Unit ID_ DTF - RL_LB
Site ID_Remote Unit ID_ DTF - RL_MB
Site ID_Remote Unit ID_ DTF - RL_HB
Note:

LB = Low Band 698-960MHz.

MB = Mid Band 1700-2000MHz.

HB = High Band 2100-2400MHz.

Remote Unit ID = to be taken from the Antenna layout or the Schematic diagram.
I.
In case of SISO = One Remote Unit = One ID
II.
In case of MIMO = Two Remote Units = Two IDs (A &B)
Example:
Site Code = 318497
Remote Unit = 1-1 (SISO)
Remote Unit = 1-1A & 1-1B (MIMO)
File Name = 318497_1-1_DTF - RL_LB
File Name = 318497_1-1_DTF - RL_MB
File Name = 318497_1-1_DTF - RL_HB
File Name = 318497_1-1A_DTF - RL_LB
SISO
File Name = 318497_1-1B_DTF - RL_LB
File Name = 318497_1-1A_DTF - RL_MB
File Name = 318497_1-1B_DTF - RL_MB
File Name = 318497_1-1A_DTF - RL_HB
File Name = 318497_1-1B_DTF - RL_HB
MIMO
0
Page #:
11 of 12

Operating Policies & Procedures Manual
American Tower Corporation
Title :
DAS Sweep Testing SOW
Document #:
DAS-Test Standards
Rev.:
0
Page #:
12 of 12
After all coax lines have been tested and all passing results are obtained, the results must be turned into the ATC construction manager within 7 days before the Final Punch walk. The submittal process is to include system sweep data and the PDF screenshots populated in ATC workbook (attached in the appendix of this document). All native VNA files must be provided to ATC in a separate folder for further reference.
Cabling Schematic
Diagram
ATC DAS SWEEP
TESTING SOW REV 4 (041614).xlsx