ISO/IEC 21823-2:2020

Internet of things (IoT) — Interoperability for IoT systems — Part 2: Transport interoperability

ISO/IEC 21823-2:2020(E) specifies a framework and requirements for transport interoperability, in order to enable the construction of IoT systems with information exchange, peer-to-peer connectivity and seamless communication both between different IoT systems and also among entities within an IoT system. This document specifies: • transport interoperability interfaces and requirements between IoT systems; • transport interoperability interfaces and requirements within an IoT system

Internet des objets (IoT) — Interopérabilité des systèmes IoT — Partie 2: Interopérabilité de transport

General Information

• Status: Published
• Publication Date: 23-Apr-2020
• ICS: 35.020 - Information technology (IT) in general
• Technical Committee: ISO/IEC JTC 1/SC 41 - Internet of things and digital twin
• Drafting Committee: ISO/IEC JTC 1/SC 41 - Internet of things and digital twin
• Current Stage: 6060 - International Standard published
• Start Date: 24-Apr-2020
• Due Date: 15-Apr-2022
• Completion Date: 24-Apr-2020

Standards Content (Sample)

ISO/IEC 21823-2
Edition 1.0 2020-04
INTERNATIONAL
STANDARD

colour
inside
Internet of things (IoT) – Interoperability for IoT systems –
Part 2: Transport interoperability


ISO/IEC 21823-2:2020-04(en)

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ISO/IEC 21823-2


Edition 1.0 2020-04




INTERNATIONAL



STANDARD








colour

inside










Internet of things (IoT) – Interoperability for IoT systems –

Part 2: Transport interoperability



























INTERNATIONAL

ELECTROTECHNICAL

COMMISSION






ICS 35.020; 35.110 ISBN 978-2-8322-8142-0




  Warning! Make sure that you obtained this publication from an authorized distributor.

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– 2 – ISO/IEC 21823-2:2020 © ISO/IEC 2020
CONTENTS
FOREWORD . 3
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Network connectivity for transport interoperability . 6
5 Overview . 7
5.1 Network connectivity model and interfaces between IoT systems . 7
5.2 Network connectivity model and interfaces within an IoT system . 8
5.3 Network connectivity stack model . 10
6 Requirements for network connectivity between IoT systems . 12
6.1 Overview. 12
6.2 Network interfaces between different IoT systems . 13
6.2.1 Network service interface . 13
6.2.2 Network protocol translation interface . 13
6.2.3 Network resource interface . 13
6.3 Requirements of network connectivity . 13
6.3.1 General . 13
6.3.2 Service-related requirement . 13
6.3.3 Communication-related requirement . 14
6.3.4 Network resource-related requirement . 14
6.3.5 QoS requirement . 14
6.3.6 Bandwidth requirement . 15
6.3.7 Signalling requirement . 15
6.3.8 Status monitor requirement . 15
6.3.9 Security requirement . 15
6.3.10 Time-dependent requirement . 15
7 Requirements for network connectivity within an IoT system . 15
7.1 Overview. 15
7.2 Network elements for supporting network connectivity . 16
7.2.1 Network service interface . 16
7.2.2 Network protocol translation interface . 17
7.2.3 Network resource interface . 17
7.3 Gateways for supporting network connectivity . 17
Bibliography . 18

Figure 1 – Facets of IoT interoperability . 6
Figure 2 – Network connectivity model between two IoT systems . 7
Figure 3 – Network connectivity model within an IoT system . 9
Figure 4 – Network connectivity stack model between IoT systems . 10
Figure 5 – Network connectivity stack model within an IoT system . 11
Figure 6 – The connectivity between different IoT systems . 12
Figure 7 – The connectivity within an IoT system . 16

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ISO/IEC 21823-2:2020 © ISO/IEC 2020 – 3 –
INTERNET OF THINGS (IoT) –
INTEROPERABILITY FOR IoT SYSTEMS –

Part 2: Transport interoperability

FOREWORD
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International Standard ISO/IEC 21823-2 was prepared by subcommittee 41: Internet of Things
and related technologies, of ISO/IEC joint technical committee 1: Information technology.
The list of all currently available parts of the ISO/IEC 21823 series, under the general title
Internet of Things (IoT) – Interoperability for IoT systems, can be found on the IEC and ISO
websites.
The text of this International Standard is based on the following documents:
FDIS Report on voting
JTC1-SC41/138/FDIS JTC1-SC41/153/RVD

Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
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of its contents. Users should therefore print this document using a colour printer.

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INTRODUCTION
Internet of Things (IoT) systems involve communications among different entities. This applies
to connections between different IoT systems. It also applies to the many connections that exist
within IoT systems. The various entities and their connections are described in ISO/IEC 30141.
The ISO/IEC 21823 series addresses issues that relate to interoperability of the
communications between IoT systems entities, both between different IoT systems and within
a single IoT system. ISO/IEC 21823-1 describes a general framework for interoperability for IoT
systems. This includes a facet model for interoperability which includes five facets of
interoperability: transport; syntactic; semantic; behavioural; policy. This document
(ISO/IEC 21823-2) addresses the transport interoperability for IoT systems. The semantic facet
of interoperability will be addressed in a future International Standard (ISO/IEC 21823-3). The
potential other parts address the syntactic facet, the behavioural facet and the policy facet of
interoperability.
As described in ISO/IEC 30141, IoT systems have multiple different types of networks
connecting the various system entities – network connectivity, addressing the transport facet of
the interoperability model, is thus of great importance in the description of interoperability for
IoT systems. The different networks need to be combined to provide the necessary network
connectivity between entities which are attached to each of the networks – in short, to enable
those entities to be interoperable. An example are the centralized applications and services
which need to receive data from remote sensors, or issue commands to remote actuators.
Network connectivity is the name given to the methods by which the various networks in an IoT
system are connected to one another. This document specifies a framework and requirements
for transport interoperability, in order to enable the construction of IoT systems with information
exchange, peer-to-peer connectivity and seamless communication both between different IoT
systems and also among entities within an IoT system.
To provide seamless communication and interaction between and within networks, it is
important to solve network level interoperability issues in IoT systems. There are four types of
networks in IoT systems, including user networks, service network, access network and
proximity network, which are defined in ISO/IEC 30141 and used in ISO/IEC 21823-1. The
relationship and interface among these networks for supporting networks interoperability need
to be specified.
For this purpose, this document focuses on network connectivity, which is the precondition of
interoperability in IoT systems.

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ISO/IEC 21823-2:2020 © ISO/IEC 2020 – 5 –
INTERNET OF THINGS (IoT) –
INTEROPERABILITY FOR IoT SYSTEMS –

Part 2: Transport interoperability



1 Scope
This part of IEC 21823 specifies a framework and requirements for transport interoperability, in
order to enable the construction of IoT systems with information exchange, peer-to-peer
connectivity and seamless communication both between different IoT systems and also among
entities within an IoT system. This document specifies:
• transport interoperability interfaces and requirements between IoT systems;
• transport interoperability interfaces and requirements within an IoT system.
2 Normative references
ISO/IEC 20924, Internet of Things (IoT) – Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 20924 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• ISO Online browsing platform: available at http://www.iso.org/obp
• IEC Electropedia: available at http://www.electropedia.org/
3.1
network connectivity
ability to exchange information as bits and bytes, assuming that the information exchange
infrastructure is established and the underlying networks and protocols are unambiguously
defined
[SOURCE: IIC:PUB:G5:V1.01:PB:20180228. The Industrial Internet of Things Volume G5:
Connectivity Framework]
3.2
transport interoperability
interoperability where information exchange uses an established communication infrastructure
between the participating systems
Note 1 to entry: System means IoT system
Note 2 to entry: IoT device, IoT gateway, sensor and actuator are considered as a system.
[SOURCE: ISO/IEC 19941:2017, 3.1.3]

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4 Network connectivity for transport interoperability
1
ISO/IEC 21823-1 [1] describes the overview and a facet model for IoT interoperability.
Interoperability can be defined as a measure of the degree to which various kinds of systems
or components interact successfully. ISO/IEC 21823-1 [1] defines interoperability as the "ability
for two or more systems or applications to exchange information and to mutually use the
information that has been exchanged".
There is both interoperability between two or more IoT systems, and also interoperability
between entities which exist in one IoT system. Only with effective interoperability between
entities can IoT systems be reliably constructed and used, in support of the many IoT
applications which are being built.
A five-facet model of IoT interoperability is introduced in ISO/IEC 21823-1 [1] as shown in
Figure 1.

Figure 1 – Facets of IoT interoperability
This document covers network connectivity which deals with the transport facet of this model.
Network connectivity describes how the many different IoT networks connect to one another to
enable seamless communication, and how different entities, which may be connected to
different networks, are able to interoperate. Network connectivity provides common guidelines
for the interconnection and interoperation of different networks and pushes IoT large scale
application. Network connectivity is a fundamental and key aspect of transport interoperability.
Discussion of the other facets of IoT interoperability is handled by other parts of ISO/IEC 21823.
As described in ISO/IEC 30141 [2], there are four types of networks in IoT systems: user
network, service network, access network and proximity network. The relationships and
interfaces between these networks for supporting interoperability are described in
ISO/IEC 30141 [2].
This document defines a framework of transport interoperability in terms of network connection
models, interfaces and stack model.
___________
1
 Numbers in square brackets refer to the Bibliography.

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ISO/IEC 21823-2:2020 © ISO/IEC 2020 – 7 –
5 Overview
5.1 Network connectivity model and interfaces between IoT systems
Clause 5 focuses on the network interfaces between IoT systems. As shown in
ISO/IEC 30141 [2], IoT systems interact with one another through the Resources access and
interchange domain functional component, which presents one or more interfaces to support
this interaction. This is shown schematically in Figure 2. The related elements are described in
ISO/IEC 30141 [2].

Figure 2 – Network connectivity model between two IoT systems
The connectivity labelled m-1 in Figure 2 represents one or more interfaces for whichever
capabilities are offered by each of the IoT systems to the other. Communication takes place via
the use network which uses any means or protocol that is feasible for this interaction, and in
that way both user devices and digital users can communicate with the rest of the IoT system,
as defined in ISO/IEC 30141 [2]. User network only exists between Resources access and
interchange domain. When the entities in an IoT system need to collaborate with some entities
in another IoT system, the entities communicate with the Resources access and interchange
domain, which handles connections to other IoT systems.
For the two IoT systems to interoperate, each of the interfaces in m-1 that are used shall
interoperate for transport interoperability. There are many applications that have interoperability
requirements. For example, in some industrial applications, two different IoT systems share
sensor data. The entities in one IoT system use these data to make decisions. And then they
operate on the entities (such as actuators) in another IoT system through the Resources access
and interchange domain to achieve interoperation and collaboration between the two IoT
systems.

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