ISO/IEC TR 11801-9909:2020

Information technology ‑ Generic cabling for customer premises - Part 9909: Evaluation of balanced cabling in support of 25 Gbit/s for reach greater than 30 metres

ISO/IEC TR 11801-9909:2020, which is a Technical Report, covers evaluation and recommendations for achieving extended reach, greater than 30 m, for 25 Gbit/s applications over balanced cabling channels.
This document covers channel reference implementations, based on Category 8.1 and Category 8.2, 2 000 MHz, components.
The channel and component category specifications covered in this document are not intended to be normative.
The contents of the corrigendum of January 2024 have been included in this copy.

General Information

• Status: Published
• Publication Date: 21-Jun-2020
• ICS: 35.200 - Interface and interconnection equipment
• Technical Committee: ISO/IEC JTC 1/SC 25 - Interconnection of information technology equipment
• Current Stage: PPUB - Publication issued
• Start Date: 22-Jun-2020
• Completion Date: 23-Jun-2020

Relations

• Corrected By: ISO/IEC TR 11801-9909:2020/COR1:2024 - Corrigendum 1 - Information technology ‑ Generic cabling for customer premises - Part 9909: Evaluation of balanced cabling in support of 25 Gbit/s for reach greater than 30 metres
• Effective Date: 12-Jan-2024

Overview

ISO/IEC TR 11801-9909:2020 is a Technical Report that evaluates and gives recommendations for achieving extended reach (>30 metres) for 25 Gbit/s data transmission over balanced cabling. The report assesses channel reference implementations based on Category 8.1 and Category 8.2 (2 000 MHz) components and describes enhancement methods to increase signal-to-noise ratio (SNR) and extend reach beyond the 30 m typical target for 25G applications. The copy includes the January 2024 corrigendum. Note: the channel and component category specifications in this TR are informative, not normative.

Key Topics

• Extended reach ranges evaluated: ≤ 40 m, ≤ 50 m, ≤ 67 m, and ≤ 100 m.
• Channel reference implementations: two-connection channels with two 2 m, 20% derated patch cords so permanent link length = channel length − 4 m.
• Performance parameters and requirements (informative formulas and example specifications):
  • Insertion loss (IL) and return loss (RL)
  • Near-end crosstalk (NEXT) and pair-to-pair NEXT
  • Attenuation-to-crosstalk ratios (ACR-N, ACR-F) and ANEXT
  • Alien (exogenous) crosstalk and PS ANEXT / AACR-F considerations
  • DC loop resistance, propagation delay, and delay skew
  • Unbalance attenuation (TCL/ELTCTL) and coupling attenuation
• Enhancement methods: reduced dielectric delay and delay skew, enhanced cable and connector designs to improve SNR margin and capacity.
• Informative annexes: Annex A (reduced delay and delay skew) and Annex B (enhanced capacity, margin-to-capacity analysis).

Applications

ISO/IEC TR 11801-9909:2020 supports planning and evaluation for real-world high-speed use cases that may need >30 m reach at 25 Gbit/s:

• 25 Gbit/s LAN links (including 25GBASE-T considerations)
• Extended-reach high-definition audio/video distribution
• Backhaul for high-capacity Wi‑Fi access (>10 Gbit/s)
• 5G in-building deployments and small cell fronthaul
• Data center copper links, enterprise edge and horizontal cabling where longer copper runs offer cost or deployment advantages

Who should use this standard

• Network architects and infrastructure designers planning 25 Gbit/s copper channels
• Cabling manufacturers and connector designers evaluating enhanced Category 8.1/8.2 components
• Installation contractors and test laboratories performing structured cabling verification per ISO/IEC 11801-1 and IEC 61935-1
• Equipment vendors assessing compatibility and SNR margin for 25GBASE-T link implementations

Related standards

• ISO/IEC 11801-1 (Generic cabling – Part 1: General requirements)
• IEC 61935-1 (cabling test procedures)
• ISO/IEC/IEEE 8802-3:2017/AMD3:2017 (25GBASE-T)
• ISO/IEC TR 11801-9905 (referenced for 25GBASE-T link segment information)

Keywords: ISO/IEC TR 11801-9909:2020, 25 Gbit/s, balanced cabling, extended reach, Category 8.1, Category 8.2, 25GBASE-T, structured cabling, SNR, channel specifications.

Standards Content (Sample)

ISO/IEC TR 11801-9909
Edition 1.0 2020-06
TECHNICAL
REPORT
colour
inside
Information technology – Generic cabling for customer premises –
Part 9909: Evaluation of balanced cabling in support of 25 Gbit/s for reach
greater than 30 metres
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ISO/IEC TR 11801-9909
Edition 1.0 2020-06
TECHNICAL
REPORT
colour
inside
Information technology – Generic cabling for customer premises –

Part 9909: Evaluation of balanced cabling in support of 25 Gbit/s for reach

greater than 30 metres
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 35.200 ISBN 978-2-8322-8487-2

– 2 – ISO/IEC TR 11801-9909:2020
© ISO/IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 7
4 Extended reach channel specifications . 8
4.1 General . 8
4.2 Channel performance enhancement methods for increased SNR . 8
4.2.1 General . 8
4.2.2 Reduced delay and delay skew . 9
4.2.3 Enhanced cable . 9
4.2.4 Enhanced connector . 9
4.3 Example channel specifications with length scaling . 9
4.3.1 General . 9
4.3.2 Return loss (RL) . 10
4.3.3 Insertion loss (IL) . 10
4.3.4 Near-end crosstalk loss (NEXT) . 11
4.3.5 Attenuation to crosstalk loss ratio near-end (ACR-N) . 11
4.3.6 Attenuation to crosstalk ratio far-end (ACR-F) . 12
4.3.7 Alien (exogenous) crosstalk . 12
4.3.8 DC loop resistance . 13
4.3.9 Propagation delay . 13
4.3.10 Delay skew . 13
4.3.11 Unbalance attenuation near end (TCL) and far end (ELTCTL), and
coupling attenuation . 14
Annex A (informative) Reduced delay and delay skew . 15
A.1 Reduced delay relation to extended reach . 15
A.1.1 General . 15
A.1.2 Example reduced delay evaluation. 15
A.2 Delay relation to insertion loss (IL) . 15
A.2.1 General . 15
A.2.2 Relation of variable relative permittivity to attenuation . 16
A.2.3 Relation of dissipation factor to attenuation: . 16
Annex B (informative) Enhanced capacity . 18
B.1 Enhanced cabling components . 18
B.1.1 General . 18
B.1.2 Enhanced cable . 18
B.1.3 Enhanced connector . 18
B.2 Channel SNR margin-to-capacity . 18
B.2.1 General . 18
B.2.2 Margin-to-capacity calculation and comparison . 18
B.2.3 Margin-to-capacity versus frequency. 19
B.2.4 Margin-to-capacity versus reach . 20
Bibliography . 21

© ISO/IEC 2020
Figure B.1 – Margin-to-capacity versus frequency for 25 Gbit/s rate for 50 m reach . 19
Figure B.2 – Margin-to-capacity versus reach for 25 Gbit/s at 1 000 MHz frequency . 20

Table 1 – Enhancement methods for 25 Gbit/s extended reach . 9
Table 2 – Formulae for return loss specifications for example 50 m channel . 10
Table 3 – Formulae for insertion loss specifications for example 50 m channel . 10
Table 4 – Formulae for pair-to-pair NEXT specifications for example 50 m channel . 11
Table 5 – Formula for PS NEXT specifications for example 50 m channel . 11
Table 6 – Formulae for ACR-F specifications for example 50 m channel . 12
Table 7 – Formulae for PS ACR-F specifications for example 50 m channel . 12
Table 8 – Formulae for PS ANEXT specifications for example 50 m channel . 13
Table 9 – Formulae for PS AACR-F specifications for example 50 m channel . 13
Table 10 – Formulae for propagation delay specifications for a 50 m channel . 13
Table 11 – Delay skew specifications for a 50 m channel . 13
Table 12 – TCL for example 50 m channel . 14
Table 13 – ELTCTL for example 50 m channel . 14
Table 14 – Coupling attenuation for example 50 m channel for E and E . 14
1 2
– 4 – ISO/IEC TR 11801-9909:2020
© ISO/IEC 2020
INFORMATION TECHNOLOGY –
GENERIC CABLING FOR CUSTOMER PREMISES –

Part 9909: Evaluation of balanced cabling in support
of 25 Gbit/s for reach greater than 30 metres

FOREWORD
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However, a technical committee may propose the publication of a Technical Report when it has
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Standard, for example "state of the art".
ISO/IEC TR 11801-9909, which is a Technical Report, has been prepared by subcommittee 25:
Interconnection of information technology equipment, of ISO/IEC joint technical committee 1:
Information technology.
The list of all currently available parts of the ISO/IEC 11801 series, under the general title
Information technology – Generic cabling for customer premises, can be found on the IEC and
ISO websites.
© ISO/IEC 2020
The text of this Technical Report is based on the following documents:
DTR Report on voting
JTC1-SC25/2932/DTR JTC1-SC25/2948/RVDTR

Full information on the voting for the approval of this Technical Report 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.

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.

– 6 – ISO/IEC TR 11801-9909:2020
© ISO/IEC 2020
INTRODUCTION
This document provides an evaluation of balanced cabling in support of 25 Gbit/s data
transmission. The evaluation covers enhanced balanced cabling channel specifications, which
are based on Category 8.1 and Category 8.2 balanced cabling components. The enhanced
channel specifications are intended to support extended reach greater than 30 m.
The extended reach evaluation is intended to support various emerging use-cases including
• 25 Gbit/s LAN,
• extended reach high definition audio/video,
• Wi-Fi® application greater than 10 Gbit/s, and
• 5G intrabuilding sites.
___________
Wi-Fi is a registered trademark of Wi-Fi Alliance. This information is given for the convenience of users of this
document and does not constitute an endorsement by ISO or IEC.

© ISO/IEC 2020
INFORMATION TECHNOLOGY –
GENERIC CABLING FOR CUSTOMER PREMISES –

Part 9909: Evaluation of balanced cabling in support
of 25 Gbit/s for reach greater than 30 metres

1 Scope
This part of ISO/IEC 11801, which is a Technical Report, covers evaluation and
recommendations for achieving extended reach, greater than 30 m, for 25 Gbit/s applications
over balanced cabling channels.
This document covers channel reference implementations, based on Category 8.1 and Category
8.2, 2 000 MHz, components.
The channel and component category specifications covered in this document are not intended
to be normative.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
ISO/IEC 11801-1, Information technology – Generic cabling for customer premises –
Part 1: General requirements
3 Terms and definitions
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 11801-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.2 Abbreviated terms
For the purposes of this document, the abbreviated terms given in ISO/IEC 11801-1 and the
following apply.
SNR signal to noise ratio
NVP nominal velocity of propagation

– 8 – ISO/IEC TR 11801-9909:2020
© ISO/IEC 2020
4 Extended reach channel specifications
4.1 General
Balanced cabling channels in accordance with ISO/IEC 11801-1:2017, Class I and Class II,
are intended to support link data rate operating at 25 Gbit/s – for example,
ISO/IEC/IEEE 8802-3:2017/AMD3:2017 25GBASE-T – with link reach up to 30 m.
NOTE 1 ISO/IEC/IEEE 8802-3:2017/AMD3:2017 25GBASE-T link segment specifications are referenced, see
ISO/IEC TR 11801-9905.
Class I and Class II balanced cabling channels in accordance with ISO/IEC 11801-1:2017 are
implemented using Category 8.1 and Category 8.2 balanced screened cabling components,
respectively.
NOTE 2 ISO/IEC/IEEE 8802-3:2017/AMD3:2017 25GBASE-T is defined using Category 8.1 and Category 8.2 (Class I
and Class II, respectively) up to 1 250 MHz.
ISO/IEC 11801-1 allows for variation in channel implementation configurations that maintain
conformance to channel specifications.
Enhanced channel reference implementations use two connections, with two 2 m, 20 % derated
cords attached to the ends of a permanent link, so that the permanent link length is equal to
the channel length (in metres) minus 4 m.
Enhanced channels can provide additional SNR margin-to-capacity, which can potentially
support additional reach, see Annex B.
NOTE 3 The possibility of additional reach can be verified with manufacturers of specific equipment before
deployment.
Extended reach channel reference implementations, greater than 30 m, are evaluated over four
reach ranges: ≤ 40 m, ≤ 50 m, ≤ 67 m, and ≤ 100 m; see Table 1.
Balanced cabling covered by this document:
a) is specified in accordance with ISO/IEC 11801-1;
b) is tested in accordance with ISO/IEC 11801-1, i.e. as specified in IEC 61935-1.
4.2 Channel performance enhancement methods for increased SNR
4.2.1 General
Table 1 shows the enhancement method considerations for 25 Gbit/s and 25GBASE-T operation
over various extended reach cabling channels using Category 8.1 and Category 8.2
components.
NOTE 25GBASE-T can be supported only by channels which fully conform to the ISO/IEC/IEEE 8802-3:2017/AMD3
25GBASE-T link segment specifications, see 4.2.2.

© ISO/IEC 2020
Table 1 – Enhancement methods for 25 Gbit/s extended reach
Channel length, L
m
Reach range 30 < L ≤ 40 40 < L ≤ 50 50 < L ≤ 67 68 < L ≤ 100
Application 25 Gbit/s and 25 Gbit/s 25 Gbit/s 25 Gbit/s
supported 25GBASE-T
Recommended channel enhancement method
Channel Reduced delay and Reduced delay and Reduced delay and Reduced delay and
component delay skew in delay skew in delay skew in delay skew in
Category 8.1 accordance with accordance with accordance with accordance with
4.2.2. 4.2.2, and 4.2.2, 4.2.2,
Enhanced cable in Enhanced cable in Enhanced cable in
accordance with accordance with accordance with
4.2.3. 4.2.3, and 4.2.3, and
Enhanced Enhanced
connector in connector in
accordance with accordance with
4.2.4. 4.2.4.
Channel Red
...