IEC 61935-1:2019

IEC 61935-1 ®
Edition 5.0 2019-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Specification for the testing of balanced and coaxial information technology
cabling –
Part 1: Installed balanced cabling as specified in ISO/IEC 11801-1 and related
standards
Spécification relative aux essais des câblages symétriques et coaxiaux des
technologies de l’information –
Partie 1: Câblages symétriques installés selon les spécifications de
l’ISO/IEC 11801-1 et des normes connexes

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IEC 61935-1 ®
Edition 5.0 2019-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Specification for the testing of balanced and coaxial information technology

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

standards
Spécification relative aux essais des câblages symétriques et coaxiaux des

technologies de l’information –

Partie 1: Câblages symétriques installés selon les spécifications de

l’ISO/IEC 11801-1 et des normes connexes

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.120.10 ISBN 978-2-8322-7301-2

– 2 – IEC 61935-1:2019 © IEC 2019
CONTENTS
FOREWORD . 9
INTRODUCTION . 11
1 Scope . 12
2 Normative references . 13
3 Terms, definitions and abbreviations . 15
3.1 Terms and definitions . 15
3.2 Acronyms . 17
4 Reference measurement procedures for electrical properties . 18
4.1 General . 18
4.2 Common measurement considerations . 19
4.2.1 Test equipment consideration . 19
4.2.2 Network analyser test requirements . 19
4.2.3 Test set-up . 19
4.2.4 Termination of conductor pairs . 19
4.2.5 Reference loads for calibration . 20
4.2.6 Test configurations . 20
4.2.7 Coaxial cables and test leads for network analysers . 21
4.2.8 Balanced test leads . 21
4.2.9 Balun requirements. 22
4.2.10 Balunless . 24
4.2.11 Network analyser measurement precautions . 24
4.2.12 Data reporting and accuracy . 25
4.2.13 Frequency step size. 25
4.3 DC loop resistance. 25
4.3.1 Objective . 25
4.3.2 Test method . 25
4.3.3 Test equipment and set-up . 25
4.3.4 Procedure . 26
4.3.5 Test report . 26
4.3.6 Uncertainty . 26
4.3.7 DC loop resistance recalculation . 26
4.4 Direct current (DC) resistance unbalance . 27
4.4.1 Objective . 27
4.4.2 Test method . 27
4.4.3 Test equipment and set-up . 27
4.4.4 Procedure . 27
4.4.5 Test report . 28
4.4.6 Uncertainty . 28
4.5 Direct current (DC) resistance unbalance between pairs . 28
4.5.1 Objective . 28
4.5.2 Test method . 28
4.5.3 Test equipment and set-up . 29
4.5.4 Procedure . 29
4.5.5 Test report . 29
4.5.6 Uncertainty . 29
4.6 Insertion loss . 29

4.6.1 Objective . 29
4.6.2 Test method . 30
4.6.3 Test equipment and set-up . 30
4.6.4 Procedure . 30
4.6.5 Temperature correction. 31
4.6.6 Uncertainty . 31
4.7 Propagation delay and delay skew . 31
4.7.1 Objective . 31
4.7.2 Test method . 31
4.7.3 Test equipment and set-up . 32
4.7.4 Procedure . 32
4.7.5 Test report . 32
4.7.6 Uncertainty . 33
4.8 Near-end cross-talk (NEXT) and power sum NEXT . 33
4.8.1 Objective . 33
4.8.2 Test method . 33
4.8.3 Test equipment and set-up . 33
4.8.4 Procedure . 34
4.8.5 Test report . 35
4.8.6 Uncertainty . 35
4.9 Attenuation to crosstalk ratio, near end (ACR-N) and power sum ACR-N . 35
4.9.1 Objective . 35
4.9.2 Test method . 35
4.9.3 Test equipment and set-up . 35
4.9.4 Procedure and calculation . 35
4.9.5 Test report . 35
4.9.6 Uncertainty . 36
4.10 Far-end cross-talk (FEXT) and power sum FEXT . 36
4.10.1 Objective . 36
4.10.2 Test method . 36
4.10.3 Test equipment and set-up . 36
4.10.4 Procedure . 37
4.10.5 Test report . 38
4.10.6 Uncertainty of FEXT measurements . 38
4.11 Attenuation to crosstalk ratio, far end (ACR-F) . 38
4.11.1 Objective . 38
4.11.2 Calculation . 38
4.11.3 Test report . 39
4.11.4 Uncertainty . 39
4.12 Return loss . 39
4.12.1 Objective . 39
4.12.2 Test method . 39
4.12.3 Test equipment and set-up . 39
4.12.4 Procedure . 40
4.12.5 Test report . 40
4.12.6 Uncertainty . 40
4.13 PS alien near end crosstalk (PS ANEXT – Exogenous crosstalk) . 41
4.13.1 Objective . 41
4.13.2 Test method . 41

– 4 – IEC 61935-1:2019 © IEC 2019
4.13.3 Test equipment and set-up . 41
4.13.4 Procedure . 42
4.14 PS attenuation to alien crosstalk ratio, far end crosstalk (PS AACR-F –
Exogenous crosstalk) . 44
4.14.1 Objective . 44
4.14.2 Test method . 44
4.14.3 Test equipment and set-up . 44
4.14.4 Procedure . 45
4.15 Unbalance attenuation, near end . 48
4.15.1 Objective . 48
4.15.2 Test method . 48
4.15.3 Test equipment and set-up . 48
4.15.4 Procedure . 49
4.15.5 Test report . 52
4.15.6 Uncertainty . 52
4.16 Unbalance attenuation, far end . 52
4.16.1 Objective . 52
4.16.2 Test method . 52
4.16.3 Test equipment and set-up . 52
4.16.4 Procedure . 53
4.16.5 Test report . 54
4.16.6 Uncertainty . 54
4.17 Coupling attenuation . 54
5 Field test measurement requirements for electrical properties . 54
5.1 Introductory remark . 54
5.2 Cabling configurations tested . 55
5.3 Field test parameters . 55
5.3.1 General . 55
5.3.2 Optional field test parameters . 56
5.3.3 Inspection of workmanship and connectivity testing . 56
5.3.4 Propagation delay and delay skew . 58
5.3.5 Length . 58
5.3.6 Insertion loss . 59
5.3.7 NEXT, power sum NEXT . 59
5.3.8 ACR-N and power sum ACR-N . 60
5.3.9 ACR-F, power sum ACR-F . 60
5.3.10 Return loss . 60
5.3.11 Direct current (DC) loop resistance . 60
5.3.12 Direct current (DC) resistance unbalance between pairs . 60
5.3.13 Alien crosstalk parameters . 60
5.4 Data reporting and accuracy . 61
5.4.1 General . 61
5.4.2 Detailed results . 62
5.4.3 Summary results . 62
5.4.4 Reporting requirements for power sum alien crosstalk . 65
5.4.5 General . 66
5.4.6 Consistency checks for field testers . 66
5.4.7 Evaluation of consistency tests . 66
5.4.8 Administration system applicability . 67

5.4.9 Test equipment adapter cords for link testing . 67
5.4.10 User cords and channel testing . 67
6 Field tester measurement accuracy requirements . 67
6.1 General . 67
6.2 Measurement accuracy specifications common to level IIE, level III, level
IIIE, level IV, level V and level VI field testers . 72
6.3 Accuracy performance requirements for level IIE field testers . 73
6.4 Accuracy performance requirements for level III field testers . 75
6.5 Accuracy performance requirements for level IIIE field testers . 77
6.6 Accuracy performance requirements for level IV field testers . 78
6.7 Accuracy performance requirements for level V field testers . 80
6.8 Accuracy performance requirements for level VI field testers . 82
6.9 Field tester requirements applicable to alien crosstalk measurements . 85
6.10 Procedures for determining field tester parameters . 85
6.10.1 General . 85
6.10.2 Output signal balance (OSB) . 85
6.10.3 Common mode rejection (CMR) . 86
6.10.4 Residual NEXT . 87
6.10.5 Dynamic accuracy . 88
6.10.6 Source/load return loss . 89
6.10.7 Random noise floor. 89
6.10.8 Residual FEXT . 89
6.10.9 Directivity . 90
6.10.10 Tracking . 91
6.10.11 Source match . 91
6.10.12 Return loss of remote termination . 92
6.10.13 Constant error term of the propagation delay measurement function . 92
6.10.14 Error constant term proportional to propagation delay of the propagation
delay measurement function . 92
6.10.15 Constant error term of the delay skew measurement function . 92
6.10.16 Constant error term of the length measurement function . 93
6.10.17 Error constant proportional to the length of measurement function
(assuming the cables are taken from the same drum) . 93
6.10.18 Constant error term of the DC resistance measurement function . 93
6.10.19 Error constant term proportional to DC resistance of the DC resistance
measurement function . 93
6.10.20 Measurement floor for alien crosstalk testing during field testing . 93
6.11 Measurement error models . 94
6.11.1 General . 94
6.11.2 Error model for the insertion loss measurement function . 95
6.11.3 Error model for the NEXT measurement function . 95
6.11.4 Error model for the power sum NEXT measurement function . 96
6.11.5 Error model for the ACR-N measurement function . 96
6.11.6 Error model for the power sum ACR-N measurement function. 97
6.11.7 Error model for the ELFEXT or ACR-F measurement function . 97
6.11.8 Error model for the power sum ELFEXT and PS ACR-F measurement
functions . 98
6.11.9 Error model for the return loss measurement function . 98
6.11.10 Error model for the propagation delay measurement function. 99
6.11.11 Error model for the delay skew measurement function . 100

– 6 – IEC 61935-1:2019 © IEC 2019
6.11.12 Error model for the length measurement function . 100
6.11.13 Error model for the DC loop resistance measurement function . 100
6.12 Network analyser measurement comparisons . 101
6.12.1 General . 101
6.12.2 Comparison method . 101
Annex A (informative) Uncertainty and variability of field test results . 103
A.1 General . 103
A.2 Marginal results reporting . 103
A.3 Nominal accuracy . 103
A.4 Variability in link measurements not included in the measurement accuracy . 104
A.5 Variability in channel measurements . 104
A.6 Field tester accuracy checks . 105
A.6.1 General . 105
A.6.2 Manipulating cords of link adapter . 105
A.6.3 Exchanging adapters to main and remote field tester units . 105
A.6.4 Location of main and remote field tester units . 105
A.6.5 Use of previously characterized links . 105
A.6.6 Use separately characterized links using laboratory equipment . 105
A.6.7 Guidelines for correct installation testing . 106
Annex B (informative)  Reference laboratory test configuration for alien crosstalk
testing . 107
B.1 General . 107
B.2 Test parameters . 107
B.3 Link and channel construction . 107
B.4 Determination of number of disturbing links or channels . 109
B.5 Computation of results . 109
B.5.1 General . 109
B.5.2 Computation of Class I and Class II results. 109
B.6 Test report . 110
Annex C (informative) General information on power sum alien crosstalk performance
of installations . 111
Annex D (informative) Baluns. 112
D.1 General . 112
D.2 Legacy test baluns . 112
Annex E (normative) Requirements for field testing of alien crosstalk . 115
E.1 General . 115
E.2 Power sum alien crosstalk . 115
E.2.1 Objective . 115
E.2.2 Test method . 115
E.2.3 Test equipment and set-up . 115
E.2.4 Measuring ANEXT loss . 116
E.2.5 Measuring AFEXT loss . 116
E.2.6 Procedure . 117
E.2.7 Selection of test ports . 120
E.2.8 Test report . 122
E.2.9 Uncertainty of PS alien crosstalk measurements. 122
Bibliography . 123

Figure 1 – Resistor load . 19
Figure 2 – Reference planes for permanent link, CP link and channel . 21
Figure 3 – 180° hybrid used as a balun . 22
Figure 4 – Loop resistance measurement. 26
Figure 5 – DC resistance unbalance measurement . 28
Figure 6 – Insertion loss test configuration . 30
Figure 7 – NEXT test configuration . 33
Figure 8 – FEXT test configuration . 37
Figure 9 – Return loss test configuration . 40
Figure 10 – ANEXT measurement . 42
Figure 11 – Alien far end crosstalk measurement . 45
Figure 12 – Unbalance attenuation, near end test configuration . 49
Figure 13 – Back-to-back balun differential mode insertion loss measurement . 50
Figure 14 – Back-to-back balun common mode insertion loss measurement . 50
Figure 15 – Unbalance performance test of the measurement balun . 51
Figure 16 – Unbalance attenuation far end test configuration . 53
Figure 17 – Correct pairing . 57
Figure 18 – Incorrect pairing . 58
Figure 19 – Example of equipment tolerance region (NEXT) . 61
Figure 20 – Block diagram for measuring output signal balance . 86
Figure 21 – Block diagram to measure common mode rejection . 87
Figure 22 – Block diagram for measuring residual NEXT . 88
Figure 23 – Block diagram for measuring dynamic accuracy . 88
Figure 24 – Principle of measurement of residual NEXT . 90
Figure 25 – Principle of alternate measurement of residual FEXT . 90
Figure 26 – Alien crosstalk measurement floor test for the channel test configuration . 94
Figure 27 – Alien crosstalk measurement floor test for the link test configurations . 94
Figure A.1 – Source of variability during link testing . 104
Figure D.1 – Configurations for qualifying test baluns . 112
Figure D.2 – 180° hybrid used as a balun . 113
Figure E.1 – Schematic diagram to measure channel ANEXT loss . 116
Figure E.2 – AFEXT loss measurement test configuration . 117
Figure E.3 – Flow chart of the alien crosstalk test procedure . 121

Table 1 – Mixed mode S-parameter nomenclature . 22
Table 2 – Test balun performance characteristics . 23
Table 3 – Estimated uncertainty of unbalance, near end measurement . 52
Table 4 – Estimated uncertainty of unbalance, far end measurement . 54
Table 5 – Optional field test parameter measurement requirements . 56
Table 6 – Summary of reporting requirements for field test equipment (1 of 3) . 63
Table 7 – Minimum reporting requirements for PS ANEXT and PS AACR-F . 66
Table 8 – Worst case propagation delay, delay skew, DC resistance and length
measurement accuracy for level IIE, level III, level IV, level V, and VI test instruments . 68

– 8 – IEC 61935-1:2019 © IEC 2019
Table 9 – Worst case insertion loss, NEXT, ACR-N, ELFEXT/ACR-F and return loss
measurement accuracy for level IIE test instruments. 69
Table 10 – Worst case insertion loss, NEXT, ACR-N, ELFEXT/ACR-F and return loss

measurement accuracy for level III test instruments . 69
Table 11 – Worst case insertion loss, NEXT, ACR-N, ELFEXT/ACR-F and return loss
measurement accuracy for level IIIe test instruments . 70
Table 12 – Worst case insertion loss, NEXT, ACR-N, ACR-F and return loss
measurement accuracy for level IV test instruments . 70
Table 13 – Worst case insertion loss, NEXT, ACR-N, ACR-F and return loss

measurement accuracy for level V . 71
Table 14 – Worst case insertion loss, NEXT, ACR-N, ACR-F and return loss
measurement accuracy for level VI (Using Class I) . 71
Table 15 – Worst case insertion loss, NEXT, ACR-N, ACR-F and return loss
measurement accuracy for level VI (Using Class II) . 72
Table 16 – Propagation delay, delay skew, DC resistance and length accuracy

performance specifications for level IIE, III, IIIE, IV and V testers . 72
Table 17 – Propagation delay, delay skew, DC resistance, DC resistance unbalance
between pairs and length accuracy performance specifications for level VI testers . 72
Table 18 – Level IIE field tester accuracy performance parameters per IEC guidelines . 74
Table 19 – Level III field tester accuracy performance parameters per IEC guidelines . 76
Table 20 – Level IIIE field tester accuracy performance parameters per IEC guidelines . 77
Table 21 – Level IV field tester accuracy performance parameters per IEC guidelines . 79
Table 22 – Level V field tester accuracy performance parameters per IEC guidelines . 81
Table 23 – Level VI field tester accuracy performance parameters per IEC guidelines . 83
Table D.1 – Legacy test balun performance characteristics . 114

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SPECIFICATION FOR THE TESTING OF BALANCED AND
COAXIAL INFORMATION TECHNOLOGY CABLING –

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

FOREWORD
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