ISO/IEC 21823-1:2019

Internet of things (IoT) — Interoperability for IoT systems — Part 1: Framework

ISO/IEC 21823-1:2019(E) provides an overview of interoperability as it applies to IoT systems and a framework for interoperability for IoT systems. This document enables IoT systems to be built in such a way that the entities of the IoT system are able to exchange information and mutually use the information in an efficient way. This document enables peer-to-peer interoperability between separate IoT systems. This document provides a common understanding of interoperability as it applies to IoT systems and the various entities within them.

Internet des objets (IoT) — Interopérabilité des systèmes IoT — Partie 1: Cadre méthodologique

General Information

• Status: Published
• Publication Date: 18-Feb-2019
• 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
• Due Date: 04-Jul-2019
• Completion Date: 19-Feb-2019

Standards Content (Sample)

ISO/IEC 21823-1
Edition 1.0 2019-02
INTERNATIONAL
STANDARD

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Internet of things (IoT) – Interoperability for iot systems –
Part 1: Framework

ISO/IEC 21823-1:2019-02(en)

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ISO/IEC 21823-1


Edition 1.0 2019-02




INTERNATIONAL



STANDARD








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inside










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

Part 1: Framework



























INTERNATIONAL

ELECTROTECHNICAL

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ICS 33.020 ISBN 978-2-8322-6567-3



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CONTENTS
FOREWORD . 4
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Abbreviated terms . 8
5 Overview of Internet of Things interoperability . 8
5.1 Descriptions . 8
5.2 Considerations for Internet of Things interoperability . 8
5.3 Internet of Things interoperability facet model . 9
5.3.1 General . 9
5.3.2 Transport interoperability . 10
5.3.3 Syntactic interoperability . 10
5.3.4 Semantic interoperability . 11
5.3.5 Behavioural interoperability . 11
5.3.6 Policy interoperability . 11
5.3.7 Summary of Internet of Things interoperability facet model . 11
5.4 Issues affecting Internet of Things interoperability . 12
6 Consideration of the interoperability requirement for IoT characteristics . 13
6.1 General descriptions . 13
6.2 IoT system characteristics. 13
6.2.1 Network communication . 13
6.2.2 Self-description . 13
6.2.3 Other IoT system characteristics not considered in interoperability . 13
6.3 IoT component characteristics . 14
6.3.1 Discoverability . 14
6.3.2 Network connectivity . 14
6.3.3 Unique identification . 14
6.3.4 Other IoT component characteristics not considered in interoperability . 14
6.4 Legacy support . 14
6.5 Security . 14
6.5.1 Confidentiality . 14
6.5.2 Integrity . 14
6.5.3 Protection of personally identifiable information . 14
6.6 Heterogeneity . 14
6.7 Compliance . 14
6.8 Other IoT characteristics not considered in interoperability . 15
7 Framework for interoperable IoT systems based on IoT reference architecture . 15
7.1 Context for interoperability within and between IoT systems . 15
7.2 General description . 16
7.3 Interoperability of IoT entities . 17
Annex A (informative) Overall IoT infrastructure at high-level . 18
Bibliography . 20

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ISO/IEC 21823-1:2019 © ISO/IEC 2019 – 3 –
Figure 1 – Facets of IoT interoperability . 10
Figure 2 – Entities and interactions in IoT systems . 15
Figure 3 – Concepts for interoperability of IoT entities . 16
Figure A.1 – Integration of an IoT system with others . 18
Figure A.2 – An overall IoT infrastructure . 19

Table 1 – Summary of different facets of IoT interoperability [1] . 12

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INTERNET OF THINGS (IoT) –
INTEROPERABILITY FOR IoT SYSTEMS –

Part 1: Framework

FOREWORD
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International Standard ISO/IEC 21823-1 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
Information technology – Internet of Things (IoT) – Interoperability for IoT systems, can be
found on the IEC and ISO websites.
The text of this standard is based on the following documents:
FDIS Report on voting
JTC1-SC41/75/FDIS JTC1-SC41/87/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 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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ISO/IEC 21823-1:2019 © ISO/IEC 2019 – 5 –
INTRODUCTION
Internet of Things (IoT) systems involve communications between 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. ISO/IEC 21823-1 describes a general
framework for interoperability of IoT systems. This includes a facet model for interoperability
which includes five facets of interoperability (i.e. transport, syntactic, semantic, behavioural
and policy). This document addresses the framework to achieve interoperability for IoT; the
specific facets are addressed in other parts of ISO/IEC 21823.

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INTERNET OF THINGS (IoT) –
INTEROPERABILITY FOR IoT SYSTEMS –

Part 1: Framework


1 Scope
This document provides an overview of interoperability as it applies to IoT systems and a
framework for interoperability for IoT systems. This document enables IoT systems to be built
in such a way that the entities of the IoT system are able to exchange information and
mutually use the information in an efficient way. This document enables peer-to-peer
interoperability between separate IoT systems.
This document ensures that all parties involved in building and using IoT systems have a
common understanding of interoperability as it applies to IoT systems and the various entities
within them.
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 30141, Internet of Things (IoT) – Reference architecture
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 http://www.iso.org/obp
• IEC Electropedia: available at http://www.electropedia.org/
3.1
interface
named set of operations that characterize the behaviour of an entity
[SOURCE: ISO 19142:2010, 4.10]
3.2
operation
specification of a transformation or query that an object may be called to execute
[SOURCE: ISO 19142:2010, 4.17]
3.3
framework
structure of processes and specifications designed to support the accomplishment of a
specific task
[SOURCE: ISO/IEEE 11073-10201:2004, 3.22]

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ISO/IEC 21823-1:2019 © ISO/IEC 2019 – 7 –
3.4
interoperability
ability for two or more systems or applications to exchange information and to mutually use
the information that has been exchanged
[SOURCE: ISO/IEC 17788:2014, 3.1.5]
3.5
transport interoperability
interoperability (3.4) 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]
3.6
syntactic interoperability
interoperability (3.4) such that the formats of the exchanged information can be understood by
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, 3.1.4
3.7
behavioural interoperability
interoperability (3.4) so that the actual result achieves the expected outcome
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, 3.1.6, modified – In the definition, "result of the exchange"
has been replaced with "result".]
3.8
policy interoperability
interoperability (3.4) while complying with the legal, organizational, and policy frameworks
applicable to 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, 3.1.7]
3.9
semantic interoperability
interoperability (3.4) so that the meaning of the data model within the context of a subject
area is understood by 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, 3.1.5, modified – The term "semantic data interoperability"
has been replaced with "semantic interoperability".]

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4 Abbreviated terms
AMQP Advanced Message Queuing Protocol
API Application Programming Interface
ASD Application & Service Domain
IoT Internet of Things
JSON JavaScript Object Notation
MQTT Message Queuing Telemetry Transport
OMD Operation & Management Domain
PII Personally Identifiable Information
RAID Resource Access & Interchange Domain
SCD Sensing & Controlling Domain
UD User Domain
PED Physical Entity Domain
5 Overview of Internet of Things interoperability
5.1 Descriptions
Clause 5 provides an overview and facet models for Internet of Things interoperability. The
goal is to ensure that parties involved in the IoT, particularly as specified in ISO/IEC 30141,
have a common understanding of IoT interoperability for their specific needs. This common
understanding helps to achieve interoperability in IoT by establishing common terminology
and concepts used to describe it, particularly as they relate to IoT entities.
5.2 Considerations for Internet of Things interoperability
Interoperability can be defined as a measure of the degree to which various kinds of systems
or components interact successfully. For the purposes of this document, interoperability is
defined in 3.4. In the context of IoT, interoperability is further described as the successful
interaction among the IoT entities specified in ISO/IEC 30141.
Interoperability, in the context of IoT, involves a number of different types of interacting
entities and their associated interfaces. While interoperability matters in sectors throughout
the economy, this document specifically focuses on the context of IoT and especially relating
to the framework for interoperability based on the IoT reference architecture defined in
ISO/IEC 30141.
There are many considerations when addressing IoT interoperability. These include:
• ability for communication between entities in different domains or between different IoT
systems;
• ability for the exchange of data between entities in different domains or between different
IoT systems;
• ability of an understanding of the meaning of exchanged data between entities in different
domains or different IoT systems;
• ability for an IoT service to work with other IoT services;
• roles and activities of functional components as defined in ISO/IEC 30141 for
interoperability.
By taking these considerations into account, this document provides a context of framework
for a better understanding of existing and future interoperability standards.

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5.3 Internet of Things interoperability facet model
5.3.1 General
Interoperability involves a number of elements, starting at the simple exchange of data bytes,
facilitating an understanding of the semantics of the exchanged information, and also an
alignment of the business processes, behaviour and policies on either side of the exchange.
Semantic, behavioural and policy interoperability can result in a significantly bigger challenge
1
than the bits and bytes. [1]
In dealing with the various interactions to which interoperability applies in IoT, it is necessary
to explore technological, information and human aspects. Moving forward, interoperability
related challenges are likely to intensify and get more difficult to manage as IoT systems grow
more complex and interconnected. In IoT systems where anything can be connected, the
complexities are further extended from technological aspects to global policies, regulation and
international law.
To discuss interoperability within the context of IoT, it is necessary to deal with different
perspectives of conceptual interoperability and identify with whom, with what, and
circumstances in which interoperability plays a vital role. This document describes these
various aspects of interoperability in terms of facets. Interoperability of two entities may be
described in terms of different facets, where each facet focuses on one aspect of
interoperability. To achieve interoperability, it is important that all facets are understood and
mutually agreed upon by interacting entities.
The interoperability facet model described in this document defines five facets within the
context of IoT interoperability. These five facets, shown in Figure 1, are transport, syntactic,
semantic, behavioural and policy. This model is derived by combining and abstracting the
European Interoperability Framework [2] and the Levels of Conceptual Interoperability Model
(LCIM) [3].
___________
1
 Numbers in square brackets refer to the Bibliography.

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Figure 1 – Facets of IoT interoperability
In Figure 1, the big circle indicates that interoperability has five facets and that they have
some effect on each other. This model was originally produced in ISO/IEC 19941 [1] and is
adapted to "Internet of Things" to achieve synergy with the system integration viewpoint in
ICT.
5.3.2 Transport interoperability
The transport interoperability is the commonality of the communication infrastructure
established to exchange data between entities. It includes the physical medium used (e.g.
wired, wireless) and the transport mechanism between various entities of an IoT system or
between different IoT systems defined as entity-based reference model in ISO/IEC 30141.
2
Examples include IEEE 802.3 (Ethernet), IEEE 802.11 (Wi-Fi® ) for the physical layer and
protocols such as TCP/IP, HTTP/S, AMQP (as specified in ISO/IEC 19464 [4]) and MQTT (as
specified in ISO/IEC 20922 [5]).
5.3.3 Syntactic interoperability
The syntactic interoperability is the ability of two or more systems or devices to exchange
information based on their syntaxes such as formats, rules, etc. Example syntaxes for
information include OWL (Web Ontology Language), RDFS (Resource Description Framework
Schema), UML (Unified Modelling Language), XML (eXtensible Markup Language), JSON (as
specified in ISO/IEC 21778 [6]), ASN.1 (as specified in the ISO/IEC 8824 series [7]), etc.
___________
2
 Wi-Fi is a registered trademark of Wi-Fi Alliance. This information is given for the convenience of users of this
document and does not constitute an endorsement by ISO or IEC.

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5.3.4 Semantic interoperability
The semantic interoperability is the ability of the entities exchanging information to
understand the meaning of the data model within the context of a subject area. Domain
concepts in an IoT system are varied and dependent on the nature of the entities concerned.
Semantic interoperability is based on the data models of the information being exchanged at
the time of that exchange. The data models depend on the nature of the entities involved and
the functional capabilities of the interfaces between them.
5.3.5 Behavioural interoperability
The behavioural interoperability is where the results of the use of the exchanged information
match the expected outcome. IoT entities are designed for a particular purpose or intention.
However, the actual use of the entity by another entity may have a different intention without
violating the other facets of interoperability.
The behavioural interoperability of an IoT entity is defined in the interface description. The
interface description includes a declaration of the interface provided by the service, often
referred to as an API. The interface declaration describes the interface in terms of a set of
operations provided by the interface and the inputs and outputs for each operation. In terms
of the interface description, behavioural interoperability requires additional information to be
supplied in terms of the expected results of each operation, including elements such as pre-
conditions, post-conditions and any sequences of operations that are necessary for
successful use of the interface. The behavioural interoperability facet abstracts from
implementation details and describes the behaviour of IoT entities in a representation-
independent way.
The behavioural interoperability can be particularly important where a particular entity (say an
actuator) is replaced with a new version offering the same interface – while the semantic and
syntactic elements of the interface can match, the behaviour might be different, producing
unexpected results.
5.3.6 Policy interoperability
The policy interoperability is defined as the ability of two or more systems to interoperate
within the legal, organizational, and policy frameworks applicable to the participating systems.
This facet concerns governmental laws and regulations, policy terms and conditions applying
to the IoT user or IoT system provider, and organizational policies covering the interactions.
5.3.7 Summary of Internet of Things interoperability facet model
See Table 1.

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Table 1 – Summary of different facets of IoT interoperability [1]
Facets Aim Objects Requirements Examples
Transport Data transfer between Physical Protocols of data HTTP/S, MQTT
systems connections transfer
Signals
Syntactic Receive data in an Data Standardized data JSON, XML,
understood format exchange formats ASN.1
Semantic Receive data using an Programmatic Common interpretation Directories, data
understood data interface of data information keys, ontologies
information model model
Behavioural Obtain expected Information Behavioural model(s) of UML models, pre-
outcomes to interface the invoked IoT entity and post-
operations conditions,
constraint
specifications
Policy Assurance that Regulatory and Conditions and control Security policies
interoperating organizational for use and access of IoT system
systems follow polices and stakeholders,
applicable regulatory interoperation restriction on
and organizational context cross-border data
policies transfer,
regulations
controlling PII

5.4 Issues affecting Internet of Things interoperability
One of the important aspects of IoT interoperability is the mutual understanding of the
semantic and behavioural facets which express concepts from a domain of interest.
Challenges related to the semantics of data, the intended use and the organizational realities
of people and processes, and the constraints of legal or regulatory frameworks tend to be far
more difficult to address. For example, transport interoperability can make it possible to
deliver data from one system to another, but political or regulatory restrictions may make the
data practically unavailable. A lack of agreement on governance structures may impose legal
risks that prevent the sharing of that data [1].
Full interoperability between two interacting systems requires that interoperability exists for all
interoperability facets. However, practically speaking, two systems can still interact
successfully even if interoperability is not achievable for all facets. For example, for the
transport interoperability facet, one system might communicate using a REST HTTP protocol
while another s
...