IEC 61156-5:2002

INTERNATIONAL IEC
STANDARD
61156-5
First edition
2002-03
Multicore and symmetrical pair/quad cables
for digital communications –
Part 5:
Symmetrical pair/quad cables with transmission
characteristics up to 600 MHz–
Horizontal floor wiring – Sectional specification
Câbles multiconducteurs à paires symétriques et quartes
pour transmissions numériques –
Partie 5:
Câbles à paires symétriques et quartes avec caractéristiques
de transmission allant jusqu'à 600 MHz –
Câble capillaire – Spécification intermédiaire

Reference number
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60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

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edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the
base publication incorporating amendment 1 and the base publication incorporating
amendments 1 and 2.
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INTERNATIONAL IEC
STANDARD
61156-5
First edition
2002-03
Multicore and symmetrical pair/quad cables
for digital communications –
Part 5:
Symmetrical pair/quad cables with transmission
characteristics up to 600 MHz–
Horizontal floor wiring – Sectional specification
Câbles multiconducteurs à paires symétriques et quartes
pour transmissions numériques –
Partie 5:
Câbles à paires symétriques et quartes avec caractéristiques
de transmission allant jusqu'à 600 MHz –
Câble capillaire – Spécification intermédiaire

 IEC 2002  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61156-5  IEC:2002(E)
CONTENTS
FOREWORD.4

1 General .5

1.1 Scope.5

1.2 Normative references .6

1.3 Installation considerations.6

1.4 Climatic conditions.6

2 Definitions, materials and cable construction.6
2.1 Definitions .6
2.2 Materials and cable construction.6
2.2.1 General remarks.6
2.2.2 Cable construction .6
2.2.3 Conductor.6
2.2.4 Insulation.6
2.2.5 Colour code of insulation.7
2.2.6 Cable element .7
2.2.7 Screening of cable element.7
2.2.8 Cable make-up .7
2.2.9 Screening of cable core .7
2.2.10 Sheath.7
2.2.11 Colour of sheath .7
2.2.12 Identification .7
2.2.13 Finished cable .8
3 Characteristics and requirements.8
3.1 General remarks.8
3.2 Electrical characteristics .8
3.2.1 Conductor resistance .8
3.2.2 Resistance unbalance.8
3.2.3 Dielectric strength.8
3.2.4 Insulation resistance .8
3.2.5 Mutual capacitance .8
3.2.6 Capacitance unbalance pair to ground.8
3.2.7 Transfer impedance.8

3.2.8 Resistance of the screen.9
3.3 Transmission characteristics.9
3.3.1 Velocity of propagation, delay and differential delay (delay skew) .9
3.3.2 Attenuation .10
3.3.3 Unbalance attenuation .11
3.3.4 Near-end crosstalk.11
3.3.5 Far-end crosstalk (FEXT).12
3.3.6 Characteristic impedance.13
3.3.7 Return loss (RL) .14
3.3.8 Screening attenuation .14
3.3.9 Coupling attenuation .14
3.3.10 Crosstalk in bundled cable .15
3.3.11 Alien crosstalk .15

61156-5  IEC:2002(E) – 3 –
3.4 Mechanical and dimensional characteristics and requirements .15

3.4.1 Dimensional requirements.15

3.4.2 Elongation at break of the conductors .15

3.4.3 Elongation at break of the insulation.15

3.4.4 Elongation at break of the sheath.15

3.4.5 Tensile strength of the sheath .15

3.4.6 Crush test of the cable.16

3.4.7 Impact test of the cable.16

3.4.8 Bending under tension .16

3.4.9 Tensile performance of the cable .16

3.5 Environmental characteristics .16
3.5.1 Shrinkage of insulation.16
3.5.2 Wrapping test of insulation after thermal ageing .16
3.5.3 Bending test of insulation at low temperature .16
3.5.4 Elongation at break of the sheath after ageing.16
3.5.5 Tensile strength of the sheath after ageing.16
3.5.6 Sheath pressure test at high temperature.16
3.5.7 Cold bend test of the cable .16
3.5.8 Heat shock test.17
3.5.9 Flame propagation characteristics of a single cable.17
3.5.10 Flame propagation characteristics of bunched cables.17
3.5.11 Acid gas evolution.17
3.5.12 Smoke generation.17
3.5.13 Toxic gas emission .17
3.5.14 Combined flame and smoke test .17
4 Introduction to the blank detail specification .17
Annex A (informative) Cable performance at temperatures higher than 20 °C.18
Annex B (informative) Insertion loss deviation as a result of cascading components
with differing impedance.22

– 4 – 61156-5  IEC:2002(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
MULTICORE AND SYMMETRICAL PAIR/QUAD CABLES

FOR DIGITAL COMMUNICATIONS –
Part 5: Symmetrical pair/quad cables

with transmission characteristics up to 600 MHz –

Horizontal floor wiring – Sectional specification

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising all
national electrotechnical committees (IEC National Committees). The object of the IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in
addition to other activities, the IEC publishes International Standards. Their preparation is entrusted to technical
committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work.
International, governmental and non-governmental organizations liaising with the IEC also participate in this
preparation. The IEC collaborates closely with the International Organization for Standardization (ISO) in accordance
with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all interested
National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form of
standards, technical specifications, technical reports or guides and they are accepted by the National Committees
in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International Standards
transparently to the maximum extent possible in their national and regional standards. Any divergence between the
IEC Standard and the corresponding national or regional standard shall be clearly indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61156-5 has been prepared by subcommittee 46C: Wires and
symmetric cables, of IEC technical committee 46: Cables, wires, waveguides, RF connectors and
accessories for communication and signalling.
The text of this standard is based on the following documents:
FDIS Report on voting
46C/511/FDIS 46C/517/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 standard should be read in conjunction with IEC 61156-1.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until 2004.
At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
61156-5  IEC:2002(E) – 5 –
MULTICORE AND SYMMETRICAL PAIR/QUAD CABLES

FOR DIGITAL COMMUNICATIONS –
Part 5: Symmetrical pair/quad cables

with transmission characteristics up to 600 MHz –

Horizontal floor wiring – Sectional specification

1 General
1.1 Scope
This sectional specification relates to IEC 61156-1: Multicore and symmetrical pair/quad cables
for digital communications – Part 1: Generic specification. The cables described herein are
specifically intended for horizontal floor wiring in class D, E and F channels, as defined in ISO/IEC
11801:2000, Information technology – Generic cabling for customer premises (see Table 1).
It covers individually screened (STP), common screened (FTP) and unscreened (UTP) pairs or
quads having a pair count of four pairs or less. The transmission characteristics of the cables are
specified at 20 °C. See Annex A for a discussion of cable performance at temperatures higher than
20 °C.
The designation "Category 5e" is used herein to describe an enhanced Category 5 cable and is
used in the same context as "Category 5" in ISO/IEC 11801. This enhanced cable is designated
Category 5e to differentiate it from the Category 5 cables described in IEC 61156-2, 61156-3, and
61156-4. Although both Category 5 and 5e cables are characterized to 100 MHz and can be used
in Class D channels, Category 5e has additional requirements, as compared to Category 5, which
make it preferred for use in systems utilizing four pairs transmitting simultaneously in both
directions.
Table 1 – Cable categories
Maximum reference
Cable designation frequency Channel designation
MHz
a
Category 5e 100 D
Category 6 250 E
Category 7 600 F
a
Some characteristics are measured up to 125 MHz in order to comply with IEEE’s request
to specify the electrical performances up to a frequency 25 % higher than the referenced
frequency.
These cables can be used for various communication systems that are under development and
which use as many as four pairs simultaneously. In this sense, this sectional specification provides
the cable characteristics required by system developers to evaluate new systems.
The cables covered by this sectional specification are intended to operate with voltages and
currents normally encountered in communication systems. These cables are not intended to be
used in conjunction with low impedance sources, for example, the electric power supplies of public
utility mains.
Though the recommended temperature range during installation is 0 °C +50 °C, the actual
temperature range during installation should be indicated in the detail specification.

– 6 – 61156-5  IEC:2002(E)
1.2 Normative references
The following referenced documents are indispensable for the application 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 11801:2000, Information technology – Generic cabling for customer premises

Publications cited in IEC 61156-1 also apply.

1.3 Installation considerations

Installation considerations will be addressed in a future revision of 1.3 of IEC 61156-1.
1.4 Climatic conditions
Under static conditions, the cables shall operate in the temperature range from –40 °C to +60 °C.
The temperature dependence of the cables is specified for screened and unscreened cables, and
should be taken into account for the design of an actual cabling systems.
2 Definitions, materials and cable construction
2.1 Definitions
See 2.1 of IEC 61156-1.
2.2 Materials and cable construction
2.2.1 General remarks
The choice of materials and cable construction shall be suitable for the intended application and
installation of the cable. Particular care shall be taken to meet any special requirements for the
fire performance (such as burning properties, smoke generation, evolution of halogen gas, etc.).
2.2.2 Cable construction
The cable construction shall be in accordance with the details and dimensions given in the relevant
detail specification.
2.2.3 Conductor
The conductor shall be a solid annealed copper conductor, in accordance with 2.2.3 of IEC 61156-1

and shall have a nominal diameter between 0,5 mm and 0,65 mm. Conductor diameter up to
0,8 mm may be used if compatible with the connecting hardware.
2.2.4 Insulation
The conductor shall be insulated with a suitable thermoplastic material. Examples of suitable
materials are:
– polyolefin;
– fluoropolymer;
– low-smoke zero-halogen thermoplastic material.
The insulation may be solid or cellular with or without a solid dielectric skin. The insulation shall
be continuous and shall have a thickness such that the completed cable meets the specified
requirements. The nominal thickness of the insulation shall be compatible with the method of
conductor termination.
61156-5  IEC:2002(E) – 7 –
2.2.5 Colour code of insulation

The colour code is not specified but shall be indicated in the relevant detail specification. The

colours shall be readily identifiable and shall correspond reasonably with the standard colours

shown in IEC 60304.
NOTE It is acceptable to mark or stripe the "a" wire with the colour of the "b" wire to facilitate pair identification.

2.2.6 Cable element
The cable element shall be a pair or quad adequately twisted.

2.2.7 Screening of cable element
When required, the screen for the cable element shall be in accordance with 2.2.7 of IEC 61156-1.
2.2.8 Cable make-up
A cross web or any other spacer may be used to separate the cable elements. The cable elements,
including cross webs or spacers, shall be assembled to form the cable core.
The core of the cable may be wrapped with a protective layer of non-hygroscopic material.
2.2.9 Screening of cable core
When required by the relevant detail specification, a screen for the cable core shall be provided.
The screen shall be in accordance with 2.2.9 of IEC 61156-1.
2.2.10 Sheath
The sheath material shall consist of a suitable thermoplastic material.
Examples of suitable materials are
– polyolefin;
– PVC;
– fluoropolymer;
– low-smoke zero-halogen thermoplastic material.
The sheath shall be continuous, having a thickness as uniform as possible. A non-metallic ripcord

may be provided. When provided, the ripcord shall be non-hygroscopic.
2.2.11 Colour of sheath
The colour of the sheath is not specified, but it should be stated in the relevant detail specification.
2.2.12 Identification
Each length of cable shall be identified as to the manufacturer, and when required, the year of
manufacture, using one of the following methods:
a) appropriately coloured threads or tapes;
b) with a printed tape;
c) printing on the cable core wrapping;
d) marking on the sheath.
– 8 – 61156-5  IEC:2002(E)
Additional markings, such as length marking, etc., are permitted on the cable sheath. If used, such

markings should be indicated in the relevant detail specification.

2.2.13 Finished cable
The finished cable shall be adequately protected for storage and shipment.

3 Characteristics and requirements

3.1 General remarks
This clause lists the characteristics and minimum requirements of a cable complying with this
sectional specification. Test methods shall be in accordance with clause 3 of IEC 61156-1. A detail
specification may be prepared to identify a specific product and its performance capabilities (see
clause 4).
3.2 Electrical characteristics
The tests shall be carried out on a cable length of not less than 100 m, unless otherwise specified.
3.2.1 Conductor resistance
When measured in accordance with 5.1 of IEC 60189-1, the maximum loop resistance shall not
exceed 19,0 Ω/100 m of cable.
3.2.2 Resistance unbalance
The conductor resistance unbalance shall not exceed 2 %.
3.2.3 Dielectric strength
The test shall be performed on conductor/conductor and, where screen(s) are present,
conductor/screen with 1,0 kV d.c. for 1 min or, alternately, with 2,5 kV d.c. for 2 s. An a.c. voltage
may be used. The a.c. voltage levels in these cases shall be 0,7kV a.c. for 1 min or, alternately,
1,7 kV a.c. for 2 s.
3.2.4 Insulation resistance
The test shall be performed both on
– conductor/conductor;
– conductor/screen (when present).
The minimum insulation resistance at 20 °C shall not be less than 5 000 MΩ/km.
3.2.5 Mutual capacitance
The mutual capacitance is not specified but may be indicated in the relevant detail specification.
3.2.6 Capacitance unbalance pair to ground
The maximum capacitance unbalance pair to ground shall not exceed 1 600 pF/km at a frequency
of 1 kHz.
3.2.7 Transfer impedance
For cables containing a screen or screens, two grades of performance are recognized for
transfer impedance. The transfer impedance shall not exceed the values shown in Table 2 at the
discrete frequencies indicated for each grade.

61156-5  IEC:2002(E) – 9 –
Table 2 – Transfer impedance
Maximum surface transfer impedance

Frequency
mΩ/m
MHz
Grade 1 Grade 2
110 50
10 10 100
30 30 200
100 60 1 000
3.2.8 Resistance of the screen
The d.c. resistance of the individual screens or an overall screen is not specified but may be
indicated in the relevant detail specification.
3.3 Transmission characteristics
All the tests shall be carried out on a cable length of 100 m, unless otherwise specified.
3.3.1 Velocity of propagation, delay and differential delay (delay skew)
3.3.1.1 Velocity of propagation
The minimum velocity of propagation for any pair within the cable is equal to or greater than 0,6 × c
for all frequencies between 4 MHz and the maximum referenced frequency. Value below 4 MHz
are given only for information purposes (see 3.3.2).
NOTE The velocity of propagation, group velocity and phase velocity are approximately equal for frequencies greater
than 4 MHz when measured on symmetric cables, i.e. when the cables are operated in a balanced mode.
3.3.1.2 Delay and differential delay (delay skew)
The delay for a specified length of cable is understood as the inverse of the velocity of
propagation. The delay shall be less than or equal to:
delay = 534 + (ns / 100 m) (1)
f
where f is the frequency in MHz.

Differential delay (delay skew) is the difference in delay between any two pairs.
3.3.1.3 Differential delay (delay skew)
When the delay is measured at 10 ± 2 °C and 40 ± 1 °C, the maximum delay skew between any
two pairs at a given temperature shall not be greater than 45 ns/100 m for cat5e and cat6 cables
and 25 ns/100 m for cat7 cables in the frequency range from 4,0 MHz to the maximum referenced
frequency.
3.3.1.4 Environmental effects
The differential delay (delay skew) between any two pairs due to temperature shall not vary by
more than ±10 ns/100 m over the temperature range from –40 °C to +60 °C within the differential
delay (delay skew) of 3.3.1.3.

– 10 – 61156-5  IEC:2002(E)
3.3.2 Attenuation
3.3.2.1 General figures
The maximum attenuation α of any pair in the frequency range indicated in Table 3 shall be less

than or equal to the value obtained from equation (2) using the corresponding values of the
constants given in Table 3.
c
α = a × f + b × f +  (dB/100 m) (2)

f
Table 3 – Attenuation, constant values
Constants
Frequency range
Cable designation
MHz
ab c
Category 5e 4 – 125 1,967 0,023 0,100
Category 6 4 – 250 1,820 0,0169 0,250
Category 7 4 – 600 1,800 0,010 0,200
For Category 5e cables, the frequency range has been extended by 25 % to 125 MHz. In this
case values above 100 MHz are for information only.
NOTE See Annex B for information about ILD.
The values in Table 4 are for information only. Because the measurement of attenuation at 1 MHz
on a length of 100 m is prone to error, these values are given in brackets for reference purposes
only.
Table 4 – Attenuation at 20 °C
Attenuation at 20 °C
dB/100 m
Cable designation
Frequency
MHz
Category 5e Category 6 Category 7
1 [2,1] [2,1] [2,0]
4 4,1 3,8 3,7
10 6,5 6,0 5,9
16 8,3 7,6 7,4
20 9,3 8,5 8,3
31,25 11,7 10,8 10,4
62,5 17,0 15,5 14,9
100 22,0 19,9 19,0
125 [24,9] 22,5 21,4
200 29,2 27,5
250 33,0 31,0
300 34,2
600 50,1
3.3.2.2 Cat5e special consideration
The constants for Category 5e in Table 3 are based on the use of patch cables having a 20 %
higher attenuation than the horizontal cable. When patch cables having an attenuation up to 50 %
higher than the horizontal cable are used, the constants should be 1,910 8; 0,022 2, and 0,200 for
a, b, and c respectively.
61156-5  IEC:2002(E) – 11 –
3.3.2.3 Environmental effects
The increase in attenuation due to elevated temperature shall not be greater than 0,4 %/°C, in the

frequency range from 1 MHz to 250 MHz and 0,6 %/°C for frequencies above 250 MHz for

unscreened cables and 0,2 %/°C for screened cables.

The method for determining compliance with this requirement is under consideration.

3.3.3 Unbalance attenuation
The minimum unbalance attenuation near-end (transverse conversion loss or TCL) shall be equal
to or greater than the value obtained from equation (3) for the frequency ranges given in Table 5.
The formula for the TCL is
TCL = 40,0 − 10 × log (f ) (dB) (3)
Table 5 – Unbalance attenuation near-end
Frequency range for TCL
Cable category
MHz
Category 5e 1 – 100
Category 6 1 – 200
Category 7 1 – 200
NOTE Unbalance attenuation near-end (TCL) for Category 7 at frequencies greater than 200 MHz is for further study.
The minimum equal level unbalance attenuation far end (equal level transverse conversion transfer
loss or EL TCTL) for all categories shall be equal to or greater than the value obtained from equation
(4) for all frequencies in the range from 1 MHz to 30 MHz.
The formula for the EL TCTL is
EL TCTL = 35,0 − 20 × log (f ) (dB) (4)
3.3.4 Near-end crosstalk (NEXT)
When measured in accordance with IEC 61156-1, the worst pair power sum near-end crosstalk,
PS NEXT, of any pair in the frequency range indicated in Table 6 shall be equal to or greater than
the value obtained from equation (5) using the corresponding value of PS NEXT(1) given in

Table 6.
PS NEXT(f ) = PS NEXT(1) − 15 × log (f ) (dB) (5)
Table 6 – Worst pair PS NEXT values
Frequency range PS NEXT(1)
Cable designation
MHz dB
Category 5e 4 – 125 62,3
Category 6 4 – 250 72,3
Category 7 4 – 600 99,4
For Category 5e cables, the frequency range has been extended by 25 % to 125 MHz. Values
above 100 MHz are for information only and are given in brackets.

– 12 – 61156-5  IEC:2002(E)
The values given in Table 7 are for information only. For those frequencies where the calculated

value of PS NEXT is greater than 75dB, the requirement shall be 75 dB.

Table 7 – PS NEXT
PS NEXT
dB
Cable designation
Frequency
MHz
Category 5e Category 6 Category 7

162 72 75
453 63 75
10 47 57 75
16 44 54 75
20 43 53 75
31,25 40 50 75
62,5 35 45 72
100 32 42 69
125 [31] 41 68
200 38 65
250 36 63
300 62
600 58
The minimum pair-to-pair NEXT for any pair combination shall be at least 3 dB better than the PS
NEXT for any pair.
3.3.5 Far-end crosstalk (FEXT)
When measured in accordance with IEC 61156-1, the worst pair power su
...