ISO/FDIS 21111-8

ISO/DISFDIS 21111-8
ISO/TC 22/SC 32
Secretariat: JISC
Date: 2026-06-0108-18
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
DISFDIS stage
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ii
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Abbreviated terms . 3
5 Communication channel/link . 4
5.1 General. 4
5.2 Specification of single channel characteristics for SCC, cable and connector . 10
5.3 Specification related to the electromagnetic interaction between SCC and ES . 11
6 Test methods . 12
6.1 Apparatus . 12
6.2 Procedure . 14
6.3 Test results . 21
Annex A (informative) Extended test setup definitions . 23
Annex B (informative) Correction method for TDR measurements . 25
Annex C (informative) Definitions for alien cross talk test setup four-around-one . 28
Bibliography . 31

iii
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 document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directiveswww.iso.org/directives).).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
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Any trade name used in this document is information given for the convenience of users and does not
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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.htmlwww.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.
This second edition cancels and replaces the first edition (ISO 21111-8:2022), which has been technically
revised.
The main changes are as follows:
— revising and addition of reference documents;
— correction of typos
— improvement of description.
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.htmlwww.iso.org/members.html.
iv
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.
[13]
In general, the Ethernet requirements are specified in ISO/IEC/IEEE 8802-3 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
[2] [3]
Interconnection (OSI) reference model specified in ISO/IEC 7498-1 and ISO/IEC 10731 .
[12]
ISO 21111-1 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 series and the amendments, the document structure, type of physical entities, in-vehicle Ethernet
specific functionalities, and so on.
[5]
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.
[6]
ISO 21111-3 specifies supplemental requirements to a physical layer capable of transmitting 1-Gbit/s over
[13]
plastic optical fibre compliantconformant with ISO/IEC/IEEE 8802-3 ISO/IEC/IEEE 8802-3,, with specific
application to communications inside road vehicles, and a test plan for physical entity conformance testing.
[8]
ISO 21111-4 specifies the optical components requirements and test methods for 1-Gbit/s optical in-vehicle
Ethernet.
[9]
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.
[10] [13]
ISO 21111-6 specifies advanced features of an ISO/IEC/IEEE 8802-3 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.
[11] [13]
ISO 21111-7 specifies the implementation for ISO/IEC/IEEE 8802-3 ISO/IEC/IEEE 8802-3,, which
defines the interface implementation for automotive applications together with requirements on components
v
[11]
used to realize this Bus Interface Network (BIN). ISO 21111-7 also defines further testing and system
[11]
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.
This document specifies the transmission media, the channel performance and the tests for an ISO/IEC/IEEE
[13]
8802-3 ISO/IEC/IEEE 8802-3 in-vehicle Ethernet.
[12]
ISO 21111-10 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.
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.
vi
vii
Figure 1 — In-vehicle Ethernet document reference according to the OSI model
viii
Road vehicles — In-vehicle Ethernet —
Part 8:
Electrical 100-Mbit/s Ethernet transmission media, components and
tests
1 Scope
This document specifies 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-
[13]
ISO/IEC/IEEE 8802-3:2021, clause96., Clause 96. These requirements are related to signal integrity
3:2021
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 8092-2, Road vehicles — Connections for on-board electrical wiring harnesses — Part 2: Terminology, test
methods and general performance requirements
ISO/DIS 8092-6, Road vehicles — Connections for on-board electrical wiring harnesses — Part 6: In-vehicle
Ethernet, general performance requirements and interface definitions
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/IEC/IEEE 8802-3:2021, 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 19642-12, Road vehicles — Automotive cables — Part 12: Dimensions and requirements for unscreened
twisted pair RF cables with a specified analogue bandwidth up to 1 GHz
ISO 21111-1, Road vehicles — In-vehicle Ethernet — Part 1: General information and definitions
IEC 60512-25-2, Connectors for electronic equipment - Tests and measurements - Part 25-2: Test 25b -
Attenuation (insertion loss)
IEC 60512-25-4, Connectors for electronic equipment - Tests and measurements - Part 25-4: Test 25d -
Propagation delay
IEC 60512-25-5, Connectors for electronic equipment - Tests and measurements - Part 25-5: Test 25e - Return
loss
IEC 60512-25-7, Connectors for electronic equipment - Tests and measurements - Part 25-7: Test 25g -
Impedance, reflection coefficient, and voltage standing wave ratio (VSWR)
IEC 60603-7-7, 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 61935-1, 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
IEC 61935-1-1, Specification for the testing of balanced and coaxial information technology cabling - Part 1-1:
Additional requirements for the measurement of transverse conversion loss and equal level transverse conversion
transfer loss
IEC 62153-1-1, Metallic communication cables test methods - Part 1-1: Electrical - Measurement of the
pulse/step return loss in the frequency domain using the Inverse Discrete Fourier Transformation (IDFT)
ISO 21111-1, Road vehicles – In-vehicle Ethernet – Part 1: General information and definitions
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/
3.1
Ethernet data cable
single twisted pair cable that can transmit 100BASE-T1 Ethernet signals
[14]
Note 1 to entry: This is specified in Reference .
3.2
PSANEXT
power sum alien near end crosstalk loss
PSANEXT
−𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴(𝑓𝑓)
𝐴𝐴
𝑗𝑗
𝑚𝑚
𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃(𝑓𝑓) =−10log ∑ 10 (1)
𝑁𝑁
𝑗𝑗=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;
ANEXT is the ANEXT
Note 1 to entry: Power sum alien near end crosstalk loss is expressed in dB.
3.23.3
PSAACRF
power sum attenuation to alien crosstalk ratio far end
PSAACRF
−𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴𝐴(𝑓𝑓)
𝐴𝐴
𝑗𝑗
𝑚𝑚
∑
𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃(𝑓𝑓) =−10log 10 (2)
𝑁𝑁
𝑗𝑗=1
𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃(𝑓𝑓) =𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃(𝑓𝑓) −𝐼𝐼𝐼𝐼(𝑓𝑓) (3)
𝑁𝑁𝑗𝑗 𝑁𝑁𝑗𝑗 𝑁𝑁
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.
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 near end crosstalk loss
PSAACRF 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
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 8802-3:2021, clause96Clause 96 (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 a maximum of 4 inline connectors for
car applications.
The combination of channel length and maximum inline connections shall be decided in accordance with the
conformance 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
[14] [15]
and ISO 19642-12 OPEN Alliance 100BASE-T1 specification and ISO
requirements (e.g. Reference
19642-12).).
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.
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 ZRF
Single channel characteristics (port 1, 2)
RL S , S
dd11 dd22
IL Sdd21
LCL S , S
dc11 dc22
LCTL Sdc12 , Sdc21
Cross talk single channel and other signals (channels/ port 1, 2 to port 3, x)
ANEXT S , S
dd31 ddx1
AFEXT Sdd32, Sddx2
a
PSANEXT N/A
b
PSAACRF N/A
ANEXTDC Sdc31, Sdcx1
ANEXTDS S , S
ds31 dsx1
AFEXTDC Sdc32, Sdcx2
AFEXTDS S , S
ds32 dsx2
a
See 3.2.
b
See 3.3.
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.
5.1.4 Definition of whole communication channel

Key
1 device 1
2 device 2
3 ES; power, signals, and other systems
4 device connector
5 SCC
6 Ethernet data cable
7 inline connector
8 cable of 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).
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)
11 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
Interaction/cross talk Dominant disturbing
Related S-parameter
Zone to differential mode source
(exemplary)
port 1 / port 2 (SCC) (if present)
1 Multi-pin connector Line(s) with high common mode Port 3A: S (S )
dc13A ds13A
noise
...