ISO 21111-8:2022

INTERNATIONAL ISO
STANDARD 21111-8
First edition
2022-08
Road vehicles — In-vehicle Ethernet —
Part 8:
Electrical 100-Mbit/s Ethernet
transmission media, components and
tests
Véhicules routiers — Ethernet embarqué —
Partie 8: Tests, composants et supports de transmission ethernet
électriques à 100 Mbit/s
Reference number
ISO 21111-8:2022(E)
© ISO 2022

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ISO 21111-8:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
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ISO 21111-8:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 Communication channel/link .4
5.1 General . 4
5.1.1 Definition of communication channel . 4
5.1.2 Operating temperature . 5
5.1.3 RF parameters . 5
5.1.4 Definition of whole communication channel . 6
5.1.5 Definition of coupling zone . 6
5.2 Specification of single channel charactoristics for SCC, cable and connector . 8
5.2.1 Specification of SCC in WCC configuration including assembly . 8
5.2.2 Specification of the cable in SCC . 9
5.2.3 Specification of the connector in SCC . 9
5.3 Specification related to the electromagnetic interaction between SCC and ES . 9
5.3.1 Specification of the connector . 9
5.3.2 Specification of SCC in WCC including assembly . 10
6 Test methods .10
6.1 Apparatus . 10
6.1.1 Test equipment . 10
6.1.2 Precautions for VNA . 11
6.1.3 VNA setting parameter . 11
6.2 Procedure .12
6.2.1 Cable . 12
6.2.2 Connector . 12
6.2.3 WCC . 14
6.3 Test results . 17
Annex A (informative) Extended test setup definitions .18
Annex B (informative) Correction method for TDR measurements .19
Annex C (informative) Definitions for alien cross talk test setup four-around-one .21
Bibliography .23
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ISO 21111-8:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/
iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 32,
Electrical and electronic components and general system aspects.
A list of all parts in the ISO 21111 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 21111-8:2022(E)
Introduction
The ISO 21111 series includes in-vehicle Ethernet requirements and test plans that are disseminated in
other international standards and complements them with additional test methods and requirements.
The resulting requirement and test plans are structured in different documents following the Open
Systems Interconnection (OSI) reference model and grouping the documents that depend on the
physical media and bit rate used.
In general, the Ethernet requirements are specified in ISO/IEC/IEEE 8802-3. The ISO 21111 series
provides supplemental specifications (e.g. wake-up, I/O functionality), which are required for in-vehicle
Ethernet applications. In road vehicles, Ethernet networks are used for different purposes requiring
different bit-rates. Currently, the ISO 21111 series specifies the 1-Gbit/s optical and 100-Mbit/s
electrical physical layer.
The ISO 21111 series contains requirement specifications and test methods related to the in-vehicle
Ethernet. This includes requirement specifications for physical layer entity (e.g. connectors, physical
layer implementations) providers, device (e.g. electronic control units, gateway units) suppliers, and
system (e.g. network systems) designers. Additionally, there are test methods specified for conformance
testing and for interoperability testing.
Safety (electrical safety, protection, fire, etc.) and electromagnetic compatibility (EMC) requirements
are out of the scope of the ISO 21111 series.
The structure of the specifications given in the ISO 21111 series conforms with the Open Systems
[1] [2]
Interconnection (OSI) reference model specified in ISO/IEC 7498-1 and ISO/IEC 10731 .
ISO 21111-1 defines the terms which are used in this series of standards and provides an overview
of the standards for in-vehicle Ethernet including the complementary relations to ISO/IEC/IEEE 8802
and the amendments, the document structure, type of physical entities, in-vehicle Ethernet specific
functionalities, and so on.
[4]
ISO 21111-2 specifies the interface between reconciliation sublayer and physical entity including
reduced gigabit media independent interface (RGMII), and the common physical entity wake-up and
synchronized link sleep functionalities, independent from physical media and bit rate.
[5]
ISO 21111-3 specifies supplemental requirements to a physical layer capable of transmitting
1-Gbit/s over plastic optical fibre compliant with ISO/IEC/IEEE 8802-3, with specific application to
communications inside road vehicles, and a test plan for physical entity conformance testing.
[6]
ISO 21111-4 specifies the optical components requirements and test methods for 1-Gbit/s optical in-
vehicle Ethernet.
[7]
ISO 21111-5 specifies, for 1-Gbit/s optical in-vehicle Ethernet, requirements on the physical layer at
system level, requirements on the interoperability test set-ups, the interoperability test plan that checks
the requirements for the physical layer at system level, requirements on the device-level physical layer
conformance test set-ups, and device-level physical layer conformance test plan that checks a set of
requirements for the OSI physical layer that are relevant for device vendors.
[8]
ISO 21111-6 specifies advanced features of an ISO/IEC/IEEE 8802-3 in-vehicle Ethernet physical
layer (often also called transceiver), e.g. for diagnostic purposes for in-vehicle Ethernet physical
layers. It specifies advanced physical layer features, wake-up and sleep features, physical layer test
suite, physical layer control requirements and conformance test plan, physical sublayers test suite and
physical sublayer requirements and conformance test plan.
[9]
ISO 21111-7 specifies the implementation for ISO/IEC/IEEE 8802-3, which defines the interface
implementation for automotive applications together with requirements on components used to realize
this Bus Interface Network (BIN). ISO 21111-7 also defines further testing and system requirements
for systems implemented according to the system specification. In addition, ISO 21111-7 defines
the channels for tests of transceivers with a test wiring harness that simulates various electrical
communication channels.
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ISO 21111-8:2022(E)
This document specifies the transmission media, the channel performance and the tests for an
ISO/IEC/IEEE 8802-3 in-vehicle Ethernet.
ISO 21111-9 specifies the data link layer requirements and conformance test plan. It specifies the
requirements and test plan for devices and systems with bridge functionality.
[10]
ISO 21111-10 specifies the application to network layer requirements and test plan. It specifies the
requirements and test plan for devices and systems that include functionality related with OSI layers
from 3 to 7.
Figure 1 shows the parts of the ISO 21111 series and the document structure.
Figure 1 — In-vehicle Ethernet document reference according to the OSI model
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INTERNATIONAL STANDARD ISO 21111-8:2022(E)
Road vehicles — In-vehicle Ethernet —
Part 8:
Electrical 100-Mbit/s Ethernet transmission media,
components and tests
1 Scope
This document defines various parameters to be tested for the communication channel between two
Ethernet devices (e.g. ECUs for automotive application) and also for the transmission media including
cables and connectors as a single component of which the communication channel consists. This
document also specifies the general RF requirements for a physical layer communication channel for
ISO/IEC/IEEE 8802-3. These requirements are related to signal integrity of the communication channel.
Test methods for electrical performances of the communication channel/link and cables and connectors
are also specified in this document.
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/IEEE 8802-3, Telecommunications and exchange between information technology systems —
Requirements for local and metropolitan area networks — Part 3: Standard for Ethernet
ISO 19642-2, Road vehicles — Automotive cables— Part 2: Test methods
ISO 21111-1, Road vehicles – In-vehicle Ethernet – Part 1: General information and definitionsIEC 60512-25(all
parts), Connectors for electronic equipment – Tests and measurements
IEC 60603-7-7:2010, Connectors for electronic equipment - Part 7-7: Detail specification for 8-way, shielded,
free and fixed connectors for data transmission with frequencies up to 600 MHz
IEC 60512-25 (all parts), Connectors for electronic equipment - Tests and measurements
IEC 61935-1 (all parts), 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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 21111-1 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
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ISO 21111-8:2022(E)
3.1
Ethernet data cable
single twisted pair cable that can transmit 100BASE-T1 Ethernet signals
Note 1 to entry: This is specified in Reference [11].
3.2
power sum alien near end crosstalk loss
PSANEXT
−ANEXTf()
N
j
m
10
PSANEXTf =−10log 10
()
10
∑
N
j=1
where
PSANEXT is the PSANEXT;
f is the frequency;
j is the disturbing signals;
N is the disturbed signal;
m is the number of disturbing pairs.
α is the ANEXT.
ANEXT
Note 1 to entry: Power sum alien near end crosstalk loss is expressed in dB.
3.3
power sum attenuation to alien crosstalk ratio far end
PSAACRF
−AACRF()f
N
j
m
10
PSAACRFf() =−10log 10
10
N ∑
j=1
AACRFf() =AFEXTf() −IL()f
Nj Nj N
where
PSAACRF is the PSAACRF;
f is the frequency;
j is the disturbing signals;
N is the disturbed signal;
m is the number of disturbing pairs;
AACRF is the AACRF;
AFEXT is the AFEXT
IL is the IL
Note 1 to entry: power sum attenuation to alien crosstalk ratio far end is expressed in dB.
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ISO 21111-8:2022(E)
4 Abbreviated terms
AACRF alien attenuation to crosstalk ratio far-end
AFEXT alien far end crosstalk loss
AFEXTDC alien far end cross conversion loss common to differential
AFEXTDS alien far end cross conversion loss single ended to differential
ANEXT alien near end crosstalk loss
ANEXTDC alien near end cross conversion loss common to differential
ANEXTDS alien near end cross conversion loss single ended to differential
CC communication channel
CIDM characteristic impedance differential mode
CUT cable under test
DUT device under test
ECU electronic control unit
ES environment system
GND ground
IL insertion loss
LCL longitudinal conversion loss
LCTL longitudinal conversion transmission loss
MDI media dependent interface
PCB printed circuit board
PSANEXT power sum alien far end crosstalk loss
PSAACRF power sum power-sum alien attenuation to crosstalk ratio far-end
RL return loss
RT room temperature
SMA sub miniature type A
SCC standalone communication channel
S-Parameter scattering parameter
TDR time domain reflectometry
VNA vector network analyser
WCC whole communication channel
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ISO 21111-8:2022(E)
5 Communication channel/link
5.1 General
5.1.1 Definition of communication channel
This clause specifies the general RF requirements for a physical layer communication channel according
to Figure 2, which shall conform with ISO/IEC/IEEE 8802-3 (100BASE-T1) for in-vehicle Ethernet
applications.
The maximum length of WCC is not defined. It depends on the characteristics of each single component.
These components should be chosen to achieve a typical length of 15 m and in maximum 4 inline
connectors for car applications.
The combination of channel length and maximum inline connections shall be decided in accordance
with the compliance with the channel RF performance specification specified in this document.
Connectors and cables which are applied to the communication channel shall fulfil at least electrical
[11]
requirements (e.g. Open Alliance TC2 100 baseT1 specification ).
Key
1 device 1
2 device 2
3 physical entity
4 device connector
5 inline connector
6 cable
7 communication channel
Figure 2 — Definition of communication channel
NOTE The number of inline connections in Figure 2 is an example.
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ISO 21111-8:2022(E)
5.1.2 Operating temperature
The communication channel requirements are valid within the temperature range of the intended
application. In general, the communication channel is used in between -40 °C and 105 °C. In some
applications, an operating temperature of 85 °C, 100 °C, or 125 °C is required.
5.1.3 RF parameters
For all parts of the communication channel, the RF requirements are defined in terms of the following
RF and S-parameter (see Table 1).
Table 1 — Definitions for RF and S - parameter
Item Parameter
Impedance
CIDM Z
RF
Single channel characteristics (port 1, 2)
RL S , S
dd11 dd22
IL S
dd21
LCL S , S
dc11 dc22
LCTL S , S
dc12 dc21
Cross talk single channel and other signals (channels/port 3 to port x)
ANEXT S , S
dd31 ddx1
AFEXT S , S
dd32 ddx2
a
PSANEXT N/A
b
PSAACRF N/A
ANEXTDC S , S
dc31 dcx1
ANEXTDS S , S
ds31 dsx1
AFEXTDC S , S
dc32 dcx2
AFEXTDS S , S
ds32 dsx2
Note In principle, the limits for S-parameter are valid in the frequency range 1 MHz
≤ f ≤ 66 MHz. For LCL, LCTL, AFEXTDC, AFEXTDS, ANEXTDC, and ANEXTDS limits are
valid up to f = 200 MHz.
a
See 3.2.
b
See 3.3.
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ISO 21111-8:2022(E)
5.1.4 Definition of whole communication channel
Key
1 device 1
2 device 2
3 power, signals, and other system
4 device connector
5 SCC
6 ethernet data cable
7 inline connector
8 cable other system
9 ES
10 WCC
Figure 3 — Definition of whole communication channel
In a practical system, the communication channel which transmits Ethernet signals is not discrete, but
coexists with power lines and control signal lines other than Ethernet signals in the wiring harness
bundle. Considering this condition, the whole communication channel (WCC) is defined in Figure 3.
Therefore, the communication channel is always subjected to electromagnetic interaction. Hereafter,
the communication channel, which is dedicated to transmit Ethernet signals, is defined as standalone
communication channel (SCC) and a cabling system which is not for Ethernet signals is defined as an
environmental system (ES).
5.1.5 Definition of coupling zone
Electromagnetic interaction between ES and SCC are separated into four different zones (Figure 4).
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ISO 21111-8:2022(E)
Key
1 zone 1
2 zone 2
3 zone 3
4 zone 4
5 port 1
6 port 3A
7 port 3B
8 port 4B (line without noise)
9 port 2 (100BASE-T1 channel)
10 port 4A (line with noise)
1 connector
12. wiring harness/cable bundle
Figure 4 — Zone concept for electromagnetic interaction between ES and SCC
Table 2 defines four coupling zones. Examples of the dominant disturbing source and related
S-parameter at each zone are shown in Table 2.
For evaluation the WCC, it should be tested as a complete system including all zones. For analysis and
optimization or evaluation of single components of WCC, the zone should be tested separately
Table 2 — Coupling zone definitions
Zone Interaction / cross talk Dominant disturbing source (if Related S-parameter (exemplary)
to differential mode present)
port 1 / port 2 (SCC)
1 Multi-pin connector Line(s) with high common mode Port 3A: S (S )
dc13A ds13A
noise
2 Connecting area connector – cable Line(s) with high common mode Port 3A: S (S )
dc13A ds13A
- untwist region outside connector noise
(valid for ECU connector and inline
connector)
Depending on the application configuration, the WCC will contain of a combination or a subset of the defined zones.
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ISO 21111-8:2022(E)
Table 2 (continued)
Zone Interaction / cross talk Dominant disturbing source (if Related S-parameter (exemplary)
to differential mode present)
port 1 / port 2 (SCC)
3 Connecting area connector – cable Line(s) with high common mode Port 3A: S (S )
dc13A ds13A
- twist region outside connector noise
4 Cable bundle wiring harness Line(s) without common mode Port 3A: S (S )
dc13A ds13A
noise and other communication
Port 3B: S
dd13B
lines
Port 4B: S
dd14B
Depending on the application configuration, the WCC will contain of a combination or a subset of the defined zones.
5.2 Specification of single channel charactoristics for SCC, cable and connector
5.2.1 Specification of SCC in WCC configuration including assembly
For the evaluation of the complete channel implementation, the requirements for WCC shall be applied.
To be able to setup a compliant 100BASE-T1 channel implementation, the cables and connectors that
fulfil the respective requirements should be used. Please refer to ISO/IEC/IEEE 8802-3:2021,96.7 for a
detailed specification.
The SCC for testing the complete WCC shall comply with the specification in Table 3.
Table 3 — Specification of SCC for WCC
Parameters Specification Test reference
c d
CIDM Z 100 Ω ± 10 % IEC 62153-1-1
RF
e a
IL S 1 MHz:  ≤ 1,0 dB IEC 61935-1
dd21
10 MHz:  ≤ 2,6 dB
33 MHz:  ≤ 4,9 dB
66 MHz:  ≤ 7,2 dB
b
RL S , S 1 MHz:  ≥ 18,0 dB
dd11 dd22
20 MHz:  ≥ 18,0 dB
66 MHz:  ≥ 12,8 dB
b
LCL S , S 1 MHz:  ≥ 43,0 dB
dc11 dc22
b
LCTL S , S 33 MHz  ≥ 43,0 dB
dc21 dc12
50 MHz:  ≥ 39,4 dB
200 MHz:  ≥ 27,3 dB
a
Logarithmic scale for loss value (dB) axis and linear interpolation for limit value at logarithmic scale of frequency
(MHz) axis are applied.
b
Linear scale for loss value (dB) axis and linear interpolation for limit value at logarithmic scale of frequency (MHz) axis
are applied.
c
Measurement is done at systems rise time of 700 ps.
d
Actual measurements are corrected with use of a proper correction method. Annex B shows the information of the
correction method. The specification is valid for the corrected value CIDM (t). Both actual measurements CIDM
corrected
(t) and corrected values CIDM (t) shall be plotted in the same graph.
measured corrected
e
Because of the deviation between IL at room temperature and temperature dependent IL of the used cable, the limit is
valid for the corrected IL according to 6.3.3.5.
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ISO 21111-8:2022(E)
5.2.2 Specification of the cable in SCC
The cables used in SCC shall fulfil the cable electrical requirements (e.g. Open Alliance TC2 100baseT1
[11]
specification ).
5.2.3 Specification of the connector in SCC
Table 4 specifies the connectors used in SCC.
Table 4 — Connector specification in SCC
Parameters Specification Test reference
c
Intra pair skew T None IEC 60512-25-4
intra_pair_x
d
CIDM Z 100 Ω ± 10 % IEC 60512-25-7
RF
b
IL S 1 MHz:  ≤ 0,025 dB IEC 60512-25-2
dd21
10 MHz:  ≤ 0,038 dB
33 MHz:  ≤ 0,05 dB
66 MHz:  ≤ 0,075 dB
a
RL S , S 1 MHz:  ≥ 38,0 dB IEC 60512-25-5
dd11 dd22
33 MHz:  ≥ 38,0 dB
66 MHz:  ≥ 30,5 dB
a
LCL S , S 1 MHz:  ≥ 46,0 dB IEC 60603-7-7
dc11 dc22
a
LCTL S , S 50 MHz:  ≥ 46,0 dB
dc21 dc12
200 MHz:  ≥ 34,0 dB
a
 Linear scale for loss value (dB) axis and linear interpolation for limit value at logarithmic scale of frequency (MHz) axis
are applied.
b
Logarithmic scale for loss value (dB) axis and linear interpolation for limit value at logarithmic scale of frequency
(MHz) axis are applied.
c
No limit, the measurement result may be used for compensation of connector propagation delay skew at the layout of
ECU.
d
Measurement is done at systems rise time of 700 ps.
5.3 Specification related to the electromagnetic interaction between SCC and ES
5.3.1 Specification of the connector
The connectors used in WCC shall comply with the specification in Table 5.
Table 5 — Specification of alien cross talk for the connector
Parameters Specification Test reference
a
ANEXT/AFEXT S , S S , S 1 MHz:  ≥ 70,4 dB IEC 60512-25-1
dd31 ddx1, dd32 ddx2
16 MHz:  ≥ 46,3 dB
33 MHz:  ≥ 40,0 dB
66 MHz:  ≥ 34,0 dB
a
 Linear scale for cross talk value (dB) axis and linear interpolation for limit value at logarithmic scale of frequency
(MHz) axis are applied.
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ISO 21111-8:2022(E)
Table 5 (continued)
Parameters Specification Test reference
a
Cross talk mode conver- S , S S , S 1 MHz:  ≥ 46,0 dB IEC 60603-7-7
dc31 dcx1, ds31 dsx1
a
sion
a
S , S S , S 50 MHz:  ≥ 46,0 dB
dC32 dcx2, ds32 dsx2
ANEXTDC/ANEXTDS
100 MHz:  ≥ 40,0 dB
AFEXTDC/ANFEXTDS
200 MHz:  ≥ 34,0 dB
a
 Linear scale for cross talk value (dB) axis and linear interpolation for limit value at logarithmic scale of frequency
(MHz) axis are applied.
5.3.2 Specification of SCC in WCC including assembly
The SCC for testing the complete WCC shall comply with the specification in Table 6.
Table 6 — Specification of SCC in WCC
Parameters Specification Test reference
b, c
PSANEXT 1 MHz:  ≥ 51,5 dB IEC 61935-1
100 MHz:   ≥ 31,5 dB
b, c
PSAACR-F 1 MHz:  ≥ 56,5 dB
100 MHz:  ≥ 16,5 dB
a
C
...