ISO/IEC TS 11801-9903:2025
(Main)Information technology - Generic cabling for customer premises - Part 9903: Modelling of channels and links
Information technology - Generic cabling for customer premises - Part 9903: Modelling of channels and links
ISO/IEC TS 11801-9903:2025 establishes modelling of limits for mixed-mode transmission parameters within and between two pairs of balanced cabling. This document consists of a detailed description of matrix modelling and gives explanations on how to convert matrices, by using the S to T and T to S matrix conversion. Further it consists of terms and definitions used, how specific parameters are modelled, alternative calculation and signal-to-noise ratio (SNR) modelling.
Chain parameters and alternative approaches and formulas are described for combining component cable and connector transmission parameters into cabling link and channel transmission parameters. S-parameter limit matrix formulas are covered, which can be transformed into T-parameter limit matrices for use in chain parameter link and channel limit formulas. The formulas are applicable to all transmission parameters for forming complete differential-mode, mixed-mode, and common-mode link and channel models.
Terms and definitions used for modelling are discussed, together with how modelling is done for specific transmission parameters. Alternative calculation models are explained, and the SNR modelling introduced.
This second edition cancels and replaces the first edition published in 2021. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) the expansion of the list of specified parameters to include mixed-mode mode-conversion and related unbalance attenuation parameters;
b) the addition of an informative annex covering the topic of signal-to-noise ratio and its relation to the S-parameter matrix channel model.
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Standards Content (Sample)
ISO/IEC TS 11801-9903
Edition 2.0 2025-09
TECHNICAL
SPECIFICATION
Information technology - Generic cabling for customer premises -
Part 9903: Modelling of channels and links
ICS 35.200 ISBN 978-2-8327-0698-5
ISO/IEC TS 11801-9903: 2025-09(en)
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CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, symbols and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Symbols and abbreviated terms . 8
4 Matrix model . 9
4.1 General . 9
4.2 Matrix definition . 10
4.2.1 General . 10
4.2.2 Quadriports . 10
4.2.3 Matrix port definition for a two-pair system representative for modelling
purposes . 10
4.2.4 Operational scattering matrix . 10
4.2.5 General naming convention . 11
4.2.6 S-matrix . 12
4.2.7 Passivity . 12
4.2.8 Operational reflection loss matrix . 13
4.2.9 Transmission matrix (T-matrix) . 13
4.2.10 S-matrix of cabling . 13
4.3 General case using mixed-mode matrices . 14
4.3.1 General . 14
4.3.2 Mixed-mode S-parameters matrix and submatrices . 14
Annex A (informative) S to T and T to S-matrix conversion formulas . 17
A.1 Overview. 17
A.2 Formulas. 17
A.2.1 S to T-matrix . 17
A.2.2 T to S matrix . 17
A.2.3 Conversion matrices . 17
Annex B (informative) Transmission model terms and definitions . 19
B.1 Comparison of namings . 19
B.2 General . 20
B.3 Background of terms and definitions . 20
B.3.1 Operational attenuation . 20
B.3.2 Operational transfer function (T ) . 22
B
B.3.3 Image or wave transfer function (T) . 22
B.3.4 Insertion transfer function of a two-port (T ) . 22
BI
B.3.5 Insertion transfer function (T ) . 22
BI
B.3.6 Operational reflection loss transfer function (T = S ) of a junction . 22
ref ref
Annex C (informative) Channel and permanent link models for balanced cabling . 24
C.1 General . 24
C.2 Insertion loss . 24
C.2.1 Insertion loss of the channel configuration . 24
C.2.2 Insertion loss of the permanent link configurations . 25
C.2.3 Assumptions for insertion loss . 25
C.3 NEXT . 26
C.3.1 NEXT of the channel configuration . 26
C.3.2 NEXT of the permanent link configurations . 26
C.3.3 Assumptions for NEXT . 27
C.4 ACR-F . 30
C.4.1 ACR-F of the channel configuration . 30
C.4.2 ACR-F for the permanent link configurations . 31
C.4.3 Assumptions for ACR-F . 31
C.5 No Return loss . 31
C.5.1 Return loss of the channel and permanent link configurations . 31
C.5.2 Assumptions for the return loss circuit analysis method . 32
C.6 PS ANEXT link modelling . 35
C.6.1 General . 35
C.6.2 PS ANEXT between connectors . 35
C.6.3 PS ANEXT between cable segments . 35
C.6.4 Principles of link modelling . 36
C.7 PS AACR-F link modelling . 36
C.7.1 General . 36
C.7.2 PS AFEXT between connectors . 36
C.7.3 PS AACR-F between cable segments . 36
C.7.4 Principles of link modelling . 37
C.7.5 Impact of PS AACR-F in channels and links with substantially different
lengths . 37
C.8 Component assumptions for modelling purposes. 40
Annex D (informative) Alternative calculation of matrix terms for limit lines . 42
D.1 General . 42
D.2 Extracting limit lines . 42
D.3 Formulas to extract the cabling limit lines. 43
D.3.1 Operational attenuation . 43
D.3.2 Crosstalk . 43
D.3.3 Reflection and return loss (RL) . 44
D.4 Component values used as input to the model . 44
D.4.1 General . 44
D.4.2 Cable . 45
D.4.3 Connections . 47
Annex E (informative) Signal-to-noise ratio modelling . 49
E.1 General . 49
E.2 Transmission system model . 49
E.2.1 General . 49
E.2.2 Transmitter pulse . 49
E.2.3 Receiving criteria . 49
E.2.4 The electrical channel . 49
E.2.5 Power spectral density (PSD): . 50
E.2.6 Noise definition . 50
E.2.7 Modulation . 51
E.2.8 Bit error ratio (BER) . 52
E.2.9 Signal-to-noise ratio (SNR) . 52
E.3 Calculation examples . 53
E.3.1 General . 53
E.3.2 Comparison with other calculations: . 53
Bibliography . 56
Figure 1 – Matrix definition of a 4-port two twisted pair system . 10
Figure 2 – Operational scattering parameters example from port 2 . 11
Figure 3 – Transmission matrix concatenation showing an example of a 2-connector
permanent link . 13
Figure B.1 – Defining the operational atten
...
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