IEC 61935-1:2015

IEC 61935-1 ®
Edition 4.0 2015-12
INTERNATIONAL
STANDARD
colour
inside
Specification for the testing of balanced and coaxial information technology
cabling –
Part 1: Installed balanced cabling as specified in ISO/IEC 11801 and related
standards
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IEC 61935-1 ®
Edition 4.0 2015-12
INTERNATIONAL
STANDARD
colour
inside
Specification for the testing of balanced and coaxial information technology

cabling –
Part 1: Installed balanced cabling as specified in ISO/IEC 11801 and related

standards
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.120.10 ISBN 978-2-8322-3057-2

– 2 – IEC 61935-1:2015 © IEC 2015

CONTENTS
FOREWORD . 9

INTRODUCTION . 11

1 Scope . 12

2 Normative references . 13

3 Terms, definitions and abbreviations . 14

3.1 Terms and definitions . 14

3.2 Abbreviations . 16
4 Reference measurement procedures for electrical properties . 17
4.1 General . 17
4.2 Balunless . 17
4.2.1 Test equipment considerations . 17
4.2.2 Network analyser test requirements . 18
4.2.3 Test set-up . 18
4.2.4 Termination of conductor pairs . 18
4.2.5 Reference loads for calibration . 19
4.2.6 Test configurations . 19
4.2.7 Coaxial cables and test leads for network analysers . 20
4.2.8 Balunless requirements balanced test leads . 20
4.2.9 Balun requirements. 21
4.2.10 Network analyser measurement precautions . 22
4.2.11 Data reporting and accuracy . 23
4.3 DC loop resistance. 23
4.3.1 Objective . 23
4.3.2 Test method . 24
4.3.3 Test equipment and set-up . 24
4.3.4 Procedure . 24
4.3.5 Test report . 24
4.3.6 Uncertainty . 24
4.3.7 DC loop resistance recalculation . 24
4.4 Direct current (DC) resistance unbalance . 25
4.4.1 Objective . 25
4.4.2 Test method . 25

4.4.3 Test equipment and set-up . 25
4.4.4 Procedure . 25
4.4.5 Test report . 26
4.4.6 Uncertainty . 26
4.5 Insertion loss . 26
4.5.1 Objective . 26
4.5.2 Test method . 26
4.5.3 Test equipment and set-up . 26
4.5.4 Procedure . 27
4.5.5 Temperature correction. 27
4.5.6 Uncertainty . 28
4.6 Propagation delay and delay skew . 28
4.6.1 Objective . 28
4.6.2 Test method . 28

4.6.3 Test equipment and set-up . 28

4.6.4 Procedure . 28

4.6.5 Test report . 29

4.6.6 Uncertainty . 29

4.7 Near-end cross-talk (NEXT) and power sum NEXT . 29

4.7.1 Objective . 29

4.7.2 Test method . 29

4.7.3 Test equipment and set-up . 29

4.7.4 Procedure . 30

4.7.5 Test report . 31

4.7.6 Uncertainty . 31
4.8 Attenuation to crosstalk ratio, near end (ACR-N) and power sum ACR-N . 31
4.8.1 Objective . 31
4.8.2 Test method . 31
4.8.3 Test equipment and set-up . 32
4.8.4 Procedure and calculation . 32
4.8.5 Test report . 32
4.8.6 Uncertainty . 32
4.9 Far-end cross-talk (FEXT) and power sum FEXT . 32
4.9.1 Objective . 32
4.9.2 Test method . 32
4.9.3 Test equipment and set-up . 32
4.9.4 Procedure . 33
4.9.5 Test report . 34
4.9.6 Uncertainty of FEXT measurements . 34
4.10 Attenuation to crosstalk ratio, far end (ACR-F) . 34
4.10.1 Objective . 34
4.10.2 Calculation . 34
4.10.3 Test report . 35
4.10.4 Uncertainty . 35
4.11 Return loss . 35
4.11.1 Objective . 35
4.11.2 Test method . 35
4.11.3 Test equipment and set-up . 35
4.11.4 Procedure . 36

4.11.5 Test report . 36
4.11.6 Uncertainty . 36
4.12 PS Alien near end crosstalk (PS ANEXT – Exogenous crosstalk) . 36
4.12.1 Objective . 36
4.12.2 Test method . 36
4.12.3 Test equipment and set-up . 36
4.12.4 Procedure . 37
4.13 PS Attenuation to alien crosstalk ratio, far end crosstalk (PS AACR-F –
Exogenous crosstalk) . 39
4.13.1 Objective . 39
4.13.2 Test method . 39
4.13.3 Test equipment and set-up . 39
4.13.4 Procedure . 40
4.14 Unbalance attenuation, near end . 43

– 4 – IEC 61935-1:2015 © IEC 2015

4.14.1 Objective . 43

4.14.2 Test method . 43

4.14.3 Test equipment and set-up . 43

4.14.4 Procedure . 44

4.14.5 Test report . 46

4.14.6 Uncertainty . 46

4.15 Unbalance attenuation, far end . 47

4.15.1 Objective . 47

4.15.2 Test method . 47

4.15.3 Test equipment and set-up . 47

4.15.4 Procedure . 48
4.15.5 Test report . 49
4.15.6 Uncertainty . 49
4.16 Coupling attenuation . 49
5 Field test measurement requirements for electrical properties . 49
5.1 Introductory remark . 49
5.2 Cabling configurations tested . 50
5.3 Field test parameters . 50
5.3.1 General . 50
5.3.2 Inspection of workmanship and connectivity testing . 50
5.3.3 Propagation delay and delay skew . 52
5.3.4 Length . 52
5.3.5 Insertion loss . 53
5.3.6 NEXT, power sum NEXT . 53
5.3.7 ACR-N and power sum ACR-N . 54
5.3.8 ELFEXT, power sum ELFEXT, ACR-F, power sum ACR-F . 54
5.3.9 Return loss . 56
5.3.10 Direct current (DC) loop resistance . 56
5.4 Power sum alien crosstalk . 56
5.4.1 Objective . 56
5.4.2 Test method . 56
5.4.3 Test equipment and set-up . 56
5.4.4 Measuring ANEXT loss . 57
5.4.5 Measuring AFEXT loss . 57
5.4.6 Procedure . 58

5.4.7 Calculation of PS ANEXT and PS AACR-F from measured data . 58
5.4.8 Selection of test ports . 61
5.4.9 Test report . 63
5.4.10 Uncertainty of PS alien crosstalk measurements. 63
5.5 Data reporting and accuracy . 63
5.5.1 General . 63
5.5.2 Detailed results . 64
5.5.3 Summary results . 65
5.5.4 Reporting requirements for power sum alien crosstalk . 69
5.5.5 General . 69
5.5.6 Consistency checks for field testers . 69
5.5.7 Evaluation of consistency tests . 70
5.5.8 Administration system applicability . 70
5.5.9 Test equipment adapter cords for link testing . 70

5.5.10 User cords and channel testing . 70

6 Field tester measurement accuracy requirements . 70

6.1 General . 70

6.2 Measurement accuracy specifications common to level IIE, level III, level

IIIE, level IV and level V field testers . 74

6.3 Accuracy performance requirements for Level IIE field testers . 74

6.4 Accuracy performance requirements for level III field testers . 76

6.5 Accuracy performance requirements for level IIIE field testers . 78

6.6 Accuracy performance requirements for level IV field testers . 79

6.7 Accuracy performance requirements for level V field testers . 81

6.8 Field tester requirements applicable to alien crosstalk measurements . 83
6.9 Procedures for determining field tester parameters . 83
6.9.1 General . 83
6.9.2 Output signal balance (OSB) . 84
6.9.3 Common mode rejection (CMR) . 84
6.9.4 Residual NEXT . 85
6.9.5 Dynamic accuracy . 86
6.9.6 Source/load return loss . 86
6.9.7 Random noise floor. 87
6.9.8 Residual FEXT . 87
6.9.9 Directivity . 88
6.9.10 Tracking . 88
6.9.11 Source match . 89
6.9.12 Return loss of remote termination . 89
6.9.13 Constant error term of the propagation delay measurement function . 89
6.9.14 Error constant term proportional to propagation delay of the propagation
delay measurement function . 89
6.9.15 Constant error term of the delay skew measurement function . 90
6.9.16 Constant error term of the length measurement function . 90
6.9.17 Error constant proportional to the length of measurement function
(assuming the cables are taken from the same drum) . 90
6.9.18 Constant error term of the DC resistance measurement function . 90
6.9.19 Error constant term proportional to DC resistance of the DC resistance
measurement function . 90
6.9.20 Measurement floor for alien crosstalk testing during field testing . 90
6.10 Measurement error models . 92

6.10.1 General . 92
6.10.2 Error model for the insertion loss measurement function . 92
6.10.3 Error model for the NEXT measurement function . 92
6.10.4 Error model for the power sum NEXT measurement function . 93
6.10.5 Error model for the ACR-N measurement function . 93
6.10.6 Error model for the power sum ACR-N measurement function. 94
6.10.7 Error model for the ELFEXT or ACR-F measurement function . 94
6.10.8 Error model for the power sum ELFEXT and PS ACR-F measurement
functions . 95
6.10.9 Error model for the return loss measurement function . 95
6.10.10 Error model for the propagation delay measurement function. 96
6.10.11 Error model for the delay skew measurement function . 97
6.10.12 Error model for the length measurement function . 97
6.10.13 Error model for the DC loop resistance measurement function . 97

– 6 – IEC 61935-1:2015 © IEC 2015

6.11 Network analyzer measurement comparisons . 97

6.11.1 General . 97

6.11.2 Adapters . 98

6.11.3 Comparison methods . 100

Annex A (informative) Uncertainty and variability of field test results . 104

A.1 General . 104

A.2 Marginal results reporting . 104

A.3 Nominal accuracy . 104

A.4 Variability in link measurements not included in the measurement accuracy . 105

A.5 Variability in channel measurements . 105
A.6 Field tester accuracy checks . 106
A.6.1 General . 106
A.6.2 Manipulating cords of link adapter . 106
A.6.3 Exchanging adapters to main and remote field tester units . 106
A.6.4 Location of main and remote field tester units . 106
A.6.5 Use of previously characterized links . 106
A.6.6 Use separately characterized links using laboratory equipment . 106
A.6.7 Guidelines for correct installation testing . 107
Annex B (normative) Reference laboratory test configuration for alien crosstalk testing . 108
B.1 General . 108
B.2 Test parameters . 108
B.3 Link and channel construction . 108
B.4 Determination of number of disturbing links or channels . 109
B.5 Computation of results . 110
B.6 Test report . 110
Annex C (informative) General information on power sum alien crosstalk performance
of installations . 111
Annex D (informative) Baluns. 112
Bibliography . 113

Figure 1 – Resistor load . 18
Figure 2 – Reference planes for permanent link, CP link and channel . 20
Figure 3 – 180° hybrid used as a balun . 21
Figure 4 – DC loop resistance measurement . 24

Figure 5 – DC resistance unbalance measurement . 26
Figure 6 – Insertion loss test configuration . 27
Figure 7 – NEXT test configuration . 30
Figure 8 – FEXT test configuration . 33
Figure 9 – Return loss test configuration . 35
Figure 10 – ANEXT measurement . 37
Figure 11 – Alien far end crosstalk measurement . 40
Figure 12 – Unbalance attenuation, near end test configuration . 44
Figure 13 – Back-to-back balun differential mode insertion loss measurement . 45
Figure 14 – Back-to-back balun common mode insertion loss measurement . 45
Figure 15 – Unbalance performance test of the measurement balun . 46
Figure 16 – Unbalance attenuation far end test configuration . 48

Figure 17 – Correct pairing . 51

Figure 18 – Incorrect pairing . 52

Figure 19 – Schematic diagram to measure channel ANEXT loss . 57

Figure 20 – AFEXT loss measurement test configuration . 58

Figure 21 – Flow chart of the alien crosstalk test procedure . 62

Figure 22 – Example of equipment tolerance region (NEXT) . 64

Figure 23 – Block diagram for measuring output signal balance . 84

Figure 24 – Block diagram to measure common mode rejection . 85

Figure 25 – Block diagram for measuring residual NEXT . 86
Figure 26 – Block diagram for measuring dynamic accuracy . 86
Figure 27 – Principle of measurement of residual FEXT . 87
Figure 28 – Principle of alternate measurement of residual FEXT . 88
Figure 29 – Alien crosstalk measurement floor test for the channel test configuration . 91
Figure 30 – Alien crosstalk measurement floor test for the link test configurations . 91
Figure 31 – Construction details of special patch cord adapter . 98
Figure 32 – Interfaces to channel by field test and laboratory equipment to compare
test results . 99
Figure 33 – Interfaces to link test configuration by field test and laboratory equipment
to compare test results . 100
Figure 34 – Sample scatter plot . 102
Figure A.1 – Source of variability during link testing . 105
Figure D.1 – Configurations for qualifying test baluns . 112

Table 1 – Mixed mode S-parameter nomenclature . 21
Table 2 – Test balun performance characteristics . 22
Table 3 – Estimated uncertainty of unbalance, near end measurement . 47
Table 4 – Estimated uncertainty of unbalance, far end measurement . 49
Table 5 – Summary of reporting requirements for field test equipment (1 of 3) . 66
Table 6 – Minimum reporting requirement for PS ANEXT and PS AACR-F . 69
Table 7 – Worst case propagation delay, delay skew, DC resistance and length
measurement accuracy for level IIE, level III, level IV and level V test instruments . 71
Table 8 – Worst case insertion loss, NEXT, ACR-N, ELFEXT/ACR-F and return loss

measurement accuracy for Level IIE test instruments . 72
Table 9 – Worst case insertion loss, NEXT, ACR-N, ELFEXT/ACR-F and return loss
measurement accuracy for Level III test instruments . 72
Table 10 – Worst case insertion loss, NEXT, ACR-N, ELFEXT/ACR-F and return loss
measurement accuracy for level IIIE test instruments. 73
Table 11 – Worst case insertion loss, NEXT, ACR-N, ELFEXT/ACR-F and return loss
measurement accuracy for level IV test instruments . 73
Table 12 – Worst case insertion loss, NEXT, ACR-N, ACR-F and return loss
measurement accuracy for level V . 74
Table 13 – Propagation delay, delay skew, DC resistance and length accuracy
performance specifications . 74
Table 14 – Level IIE field tester accuracy performance parameters per IEC guidelines . 75
Table 15 – Level III field tester accuracy performance parameters per IEC guidelines . 77
Table 16 – Level IIIE field tester accuracy performance parameters per IEC guidelines . 78

– 8 – IEC 61935-1:2015 © IEC 2015

Table 17 – Level IV field tester accuracy performance parameters per IEC guidelines . 80

Table 18 – Level V field tester accuracy performance parameters per IEC guidelines . 82

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
SPECIFICATION FOR THE TESTING OF BALANCED

AND COAXIAL INFORMATION TECHNOLOGY CABLING –

Part 1: Installed balanced cabling as specified

in ISO/IEC 11801 and related standards

FOREWORD
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International Standard IEC 61935-1 has been prepared by IEC technical committee 46:
Cables, wires, waveguides, R.F. connectors, R.F. and microwave passive components and
accessories.
This fourth edition cancels and replaces the third edition, published in 2009, and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the upper frequency goes up to 1 000 MHz;
b) test methods are now included for exogenous (alien) crosstalk;
c) a new Annex A has been added for uncertainty and variability of field test results.

– 10 – IEC 61935-1:2015 © IEC 2015

The text of this standard is based on the following documents:

FDIS Report on voting
46/574/FDIS 46/587/RVD
Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 61935 series, published under the general title Specification for
the testing of balanced and coaxial information technology cabling, can be found on the IEC
website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
Telecommunication cabling, once specified uniquely by each telecommunications application,

has evolved into a generic cabling system. Telecommunications applications now use the

ISO/IEC 11801 cabling standard to meet their cabling requirements. Formerly, connectivity

tests and visual inspection were deemed sufficient to verify a cabling installation. Now users

need more comprehensive testing in order to ensure that the link will support

telecommunications applications that are designed to operate on the generic cabling system.

This part of IEC 61935 addresses reference laboratory and field test methods and provides a

comparison of these methods.
Transmission performance depends on cable characteristics, connecting hardware, patch
cords and cross-connect cabling, the total number of connections and the care with which
they are installed and maintained. This standard provides test methods for installed cabling
and pre-fabricated cable assemblies. These test methods, where appropriate, are based on
those used for components of the cable assembly.
This Part 1 contains the test methods required for installed cabling. Part 2 contains the test
methods required for patch cords and work area cords.

– 12 – IEC 61935-1:2015 © IEC 2015

SPECIFICATION FOR THE TESTING OF BALANCED

AND COAXIAL INFORMATION TECHNOLOGY CABLING –

Part 1: Installed balanced cabling as specified

in ISO/IEC 11801 and related standards

1 Scope
This part of IEC 61935 specifies reference measurement procedures for cabling parameters
and the requirements for field tester accuracy to measure cabling parameters identified in
ISO/IEC 11801. References in this standard to ISO/IEC 11801 mean ISO/IEC 11801 or
equivalent cabling standards.
This International Standard applies when the cable assemblies are constructed of cables
complying with the IEC 61156 family of standards, and connecting hardware as specified in
the IEC 60603-7 family of standards or IEC 61076-3-104, IEC 61076-3-110, IEC 61076-2-101
and IEC 61076-2-109. Where cables and/or connectors do no
...