ISO/IEC TR 11801-9905:2018

ISO/IEC TR 11801-9905
Edition 1.0 2018-02
TECHNICAL
REPORT
Information technology – Generic cabling for customer premises –
Part 9905: Guidelines for the use of installed cabling to support 25GBASE-T
application
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ISO/IEC TR 11801-9905
Edition 1.0 2018-02
TECHNICAL
REPORT
Information technology – Generic cabling for customer premises –

Part 9905: Guidelines for the use of installed cabling to support 25GBASE-T

application
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 35.200 ISBN978-2-8322-5373-1

– 2 – ISO/IEC TR 11801-9905:2018
© ISO/IEC 2018
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviations . 8
4 Cabling channel specifications for 25 GBASE-T . 9
4.1 General . 9
4.2 25GBASE-T application specifications . 9
4.2.1 Return loss . 9
4.2.2 Insertion loss/attenuation . 10
4.2.3 NEXT . 11
4.2.4 Attenuation to crosstalk ratio at the near-end (ACR-N) . 13
4.2.5 Attenuation to crosstalk ratio at the far-end (ACR-F). . 13
4.2.6 Propagation delay . 15
4.2.7 Delay skew . 15
4.2.8 Unbalance attenuation and coupling attenuation . 15
4.2.9 Alien crosstalk . 16
4.3 Associated risk of 25GBASE-T operation over installed cabling . 17
4.4 Characterization of balanced channels using Category 7 components . 17
A
4.4.1 General . 17
4.4.2 Selection of channels for qualification . 18
4.4.3 Return loss . 18
4.4.4 Insertion loss . 19
4.4.5 Near-end crosstalk loss (NEXT) . 19
4.4.6 Attenuation to crosstalk loss ratio near-end (ACR-N) . 21
4.4.7 Attenuation to crosstalk ratio far-end (ACR-F) . 22
4.4.8 Alien (exogenous) crosstalk . 24
4.4.9 Propagation delay . 25
4.4.10 Delay skew . 25
4.4.11 Coupling attenuation . 25
4.4.12 Alien crosstalk and coupling attenuation . 26
4.5 Characterization of balanced channels using Category 7 components . 26
4.5.1 General . 26
4.5.2 Selection of channels for qualification . 27
4.5.3 Return loss . 27
4.5.4 Insertion loss . 28
4.5.5 Near-end crosstalk loss (NEXT) . 28
4.5.6 Attenuation to crosstalk loss ratio near-end (ACR-N) . 30
4.5.7 Attenuation to crosstalk ratio far-end (ACR-F) . 31
4.5.8 Alien (exogenous) crosstalk . 33
4.5.9 Propagation delay . 34
4.5.10 Delay skew . 34
4.5.11 Coupling attenuation . 34
4.5.12 Alien crosstalk and coupling attenuation . 35
4.6 Characterization of balanced channels using Category 6 components . 35
A
4.6.1 General . 35
4.6.2 Selection of channels for qualification . 36

© ISO/IEC 2018
4.6.3 Test specifications for channels made out of Category 6 components . 36
A
5 Guidance for mitigation procedures to improve the cabling of existing installations . 36
5.1 General . 36
5.2 Mitigation procedures related to internal noise . 36
5.3 Mitigation procedures related to exogenous noise (alien crosstalk) . 36
6 Guidance for cabling for new installations . 37
Bibliography . 38

Table 1 – Return loss for a channel . 9
Table 2 –Return loss values for a channel at key frequencies . 10
Table 3 – Insertion loss for a channel . 10
Table 4 – Insertion loss values for a channel at key frequencies . 11
Table 5 – NEXT for a channel . 11
Table 6 – NEXT values for a channel at key frequencies . 12
Table 7 – PS NEXT for a channel . 12
Table 8 – PS NEXT values for a channel at key frequencies . 13
Table 9 – ACR-F for a channel . 13
Table 10 – ACR-F values for a channel at key frequencies . 14
Table 11 – PS ACR -F for a channel . 14
Table 12 – PS ACR-F values for a channel at key frequencies . 14
Table 13 – Propagation delay for a channel . 15
Table 14 – Propagation delay values for a channel at key frequencies . 15
Table 15 – Delay skew for a channel . 15
Table 16 – PS ANEXT for a channel . 16
Table 17 – PS ANEXT values for a channel at key frequencies . 16
Table 18 – PS AACR-F for a channel . 17
Table 19 – PS AACR-F values for a channel at key frequencies . 17
Table 20 – Risk of 25GBASE-T operation over installed cabling channels . 17
Table 21 – Formulae for return loss limits for a channel . 18
Table 22 – Return loss limits for a channel at key frequencies . 18
Table 23 – Formula for insertion loss limits for a channel . 19
Table 24 – Insertion loss limits for a channel at key frequencies . 19
Table 25 – Formulae for pair-to-pair NEXT limits for a channel . 19
Table 26 – Pair-to-pair NEXT limits for a channel at key frequencies . 20
Table 27 – Formulae for PS NEXT limits for a channel . 20
Table 28 –PS NEXT limits for a channel at key frequencies . 20
Table 29 – ACR-N limits for a channel at key frequencies . 21
Table 30 – PS ACR-N limits for a channel at key frequencies . 22
Table 31 – Formulae for ACR-F limits for a channel . 22
Table 32 – ACR-F limits for a channel at key frequencies . 23
Table 33 – Formulae for PS ACR-F limits for a channel . 23
Table 34 – PS ACR-F limits for a channel at key frequencies . 23
Table 35 – Formulae for PS ANEXT limits for a channel . 24
Table 36 – PS ANEXT limits for a channel at key frequencies . 24

– 4 – ISO/IEC TR 11801-9905:2018
© ISO/IEC 2018
Table 37 – Formula for PS AACR-F limits for a channel . 24
Table 38 – PS AACR-F limits for a channel at key frequencies . 25
Table 39 – Formula for propagation delay limits for a channel . 25
Table 40 – Propagation delay limits for a channel at key frequencies . 25
Table 41 – Formula for coupling attenuation limits for a channel . 26
Table 42 – Coupling attenuation limits for a channel at key frequenci
...