ISO/TR 21186-2:2021

TECHNICAL ISO/TR
REPORT 21186-2
First edition
2021-02
Cooperative intelligent transport
systems (C-ITS) — Guidelines on the
usage of standards —
Part 2:
Hybrid communications
Systèmes de transport intelligents coopératifs (C-ITS) - Lignes
directrices sur l'utilisation des normes —
Partie 2: Communications hybrides
Reference number
©
ISO 2021
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 5
5 Motivations for hybrid communications support . 5
5.1 Connected and cooperative mobility . 5
5.2 Examples of use cases requiring a diversity of access technologies . 7
5.2.1 Road hazard notification (use case 1) . 7
5.2.2 Emergency call (use case 2) . 8
5.2.3 Public transport (use case 3) . 8
5.3 Hybrid communication technologies. 9
5.4 Unified communication and data management architecture . 9
5.4.1 Requirements for the unified communication and data management
architecture . 9
5.4.2 Supporting a diversity of applications with diverging communication needs .10
5.4.3 Supporting a diversity of communication paths .10
5.4.4 Supporting a diversity of access technologies and protocols.11
6 The ITS station architecture and functionalities in support of hybrid communications .12
6.1 Origins of the ITS station architecture .12
6.2 Detailed ITS station architecture .14
6.3 Design principles of the ITS station architecture .16
6.4 ITS station functionalities in support for hybrid communications .17
6.5 ITS station management entity .18
6.6 ITS station capabilities .19
6.7 ITS station service managed entity (ITS-S MSE) .20
6.8 Management of data flow types (ITS-S flow type) .22
6.9 Management of communication paths (ITS-S path) .22
6.10 Management of communication profiles (ITS-SCP) .22
6.11 Management of communication handovers .24
6.12 Management of globally unique identifiers .24
6.13 Standards necessary in support of hybrid communications .24
7 How to develop ITS application standards .25
7.1 Generic development principle .25
7.2 Specifying ITS-S application process .25
7.3 Defining data flow communication requirements .25
7.4 Registering communication requirements .26
7.5 Transmitting data .26
Bibliography .27
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 204, Intelligent transport systems, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC
278, Intelligent transport systems, in accordance with the Agreement on technical cooperation between
ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 21186 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.
iv © ISO 2021 – All rights reserved

Introduction
This document is part of a family of deliverables from Standard Development Organizations (SDOs)
for Cooperative Intelligent Transport Systems (C-ITS), which is a subset of standards for Intelligent
Transport Systems (ITS).
ITS aims to improve surface transportation in terms of:
— safety
e.g. crash avoidance, obstacle detection, emergency calls, dangerous goods;
— efficiency
e.g. navigation, green wave, priority, lane access control, contextual speed limits, car sharing;
— comfort
e.g. telematics, parking, electric vehicle charging, infotainment;
— sustainability
by applying information and communication technologies (ICT).
In the European Union, the legal framework is given by the European Commissions Mandate M/453
[53] [52]
on C-ITS , the European Commission Directive 2010/40 , and the European Commission Mandate
[54]
M/546 .
The whole set of standards for deployment of C-ITS is difficult to understand by developers of equipment
and software, especially ITS application software, and thus guidelines explaining a beneficial choice
of standards (C-ITS Release), the purpose and interaction of standardized features, beneficial
implementation approaches and guidance in developing ITS applications are a prerequisite for a fair
and open market allowing early deployment of interoperable and future-proof solutions.
The ISO 21186 series provides necessary guidelines in multiple parts, each dedicated to a specific
purpose:
[14]
— Part 1: Standardization landscape and releases ;
— Part 2: Hybrid communications (this document);
15]
— Part 3: Security .
This document can be complemented by further parts as required, for example:
— Usage of the service announcement protocol specified, for example, in ISO 22418;
— Dynamically extendable data and protocol parameters ("Information Object Classes" and
"Information Object Sets"; based on ASN.1 type CLASS);
1)
— Usage of the GTDM framework specified in ISO/TS 21184 .
The purpose of this document is thus to inform about relevant standards and to describe the
functionalities of the ITS station architecture defined in support for hybrid communication
technologies. It is intended to serve as a guideline to structure the development of new C-ITS standards
and to harmonize the deployment of C-ITS services relying on the use of hybrid communication
technologies. It also intends to give support to the developers of standards defining C-ITS services and
to the developers of C-ITS solutions and ITS applications complying with the ITS station architecture
and its set of functionalities supporting hybrid communications.
1) Under preparation. Stage at the time of publication: ISO/PRF TS 21184:2021.
At time of writing this document, no applicable Intellectual Property Rights (IPR) issues were known
related to this document. However, this document references standards, for which IPRs are known.
Information on such IPRs is expected to be provided in those respective standards, which might be
from any one of the Standards Development Organisations working on ITS or C-ITS.
Referencing other SDOs and their respective deliverables in no way is to be understood as an
endorsement, but rather as an informative piece of information.
More details on the C-ITS domain can be found in the Brochure cited in Reference [58].
vi © ISO 2021 – All rights reserved

TECHNICAL REPORT ISO/TR 21186-2:2021(E)
Cooperative intelligent transport systems (C-ITS) —
Guidelines on the usage of standards —
Part 2:
Hybrid communications
1 Scope
This document serves as a guideline explaining the concept of hybrid communications and support
functionalities for Cooperative ITS services deployed in conformance with the ITS station architecture
and related Cooperative ITS standards.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
access technology
technology employed in a communication interface to acces
...