ISO 14827-2:2022

Intelligent transport systems — Data interfaces between centres for transport information and control systems — Part 2: AP-DATEX

This document defines a platform-specific model (PSM) for data exchange, which specifically uses ASN.1 and TCP/UDP (transmission control protocol/user datagram protocol) datagrams which were defined as “DATEX-ASN” in the first edition of this document for AP-DATEX (application profile-data exchange) and other Internet protocol (IP) networks. A PSM is an actual implementation of a platform-independent model (PIM) for exchange. This document specifies the message rules and procedures for communication between different systems for ITS using TCP/UDP datagrams. This document deals mainly with the communication interfaces. It has been designed to meet the unique requirements of intelligent transport systems (ITS). However, it has also been designed in a generic fashion and thus can be used for other data exchanges as well.

Titre manque — Partie 2: Titre manque

General Information

• Status: Published
• Publication Date: 19-Dec-2022
• ICS: 03.220.01 - Transport in general
• ICS: 35.240.60 - IT applications in transport
• Technical Committee: ISO/TC 204 - Intelligent transport systems
• Drafting Committee: ISO/TC 204/WG 9 - Integrated transport information, management and control
• Current Stage: 6060 - International Standard published
• Start Date: 20-Dec-2022
• Due Date: 19-Oct-2022
• Completion Date: 20-Dec-2022

Relations

• Revises: ISO 14827-2:2005 - Transport information and control systems — Data interfaces between centres for transport information and control systems — Part 2: DATEX-ASN
• Effective Date: 26-Nov-2021

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 14827-2
Second edition
2022-12
Intelligent transport systems —
Data interfaces between centres for
transport information and control
systems —
Part 2:
AP-DATEX
Reference number
ISO 14827-2:2022(E)
© ISO 2022
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ISO 14827-2:2022(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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ISO 14827-2:2022(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction .............................................................................................................................................................................................................................. vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Symbols and abbreviated terms..........................................................................................................................................................2

5 Conformance ............................................................................................................................................................................................................ 3

6 Exchange framework.......................................................................................................................................................................................3

6.1 General ........................................................................................................................................................................................................... 3

6.2 Basic pull with TCP/UDP datagrams exchange PSM ............................................................................................ 5

6.2.1 Overview ................................................................................................................................................................................... 5

6.2.2 Exchange pattern messages definition .......................................................................................................... 6

6.2.3 State diagrams...................................................................................................................................................................... 7

6.2.4 Features implementation description ............................................................................................................. 7

6.3 Basic push TCP/UDP datagrams exchange PSM ....................................................................................................... 8

6.3.1 Overview ................................................................................................................................................................................... 8

6.3.2 Exchange pattern messages definition .......................................................................................................... 9

6.3.3 State diagrams...................................................................................................................................................................... 9

6.3.4 Features implementation description .......................................................................................................... 10

7 Data exchange procedures .....................................................................................................................................................................11

7.1 General ........................................................................................................................................................................................................ 11

7.2 General datagrams procedures ............................................................................................................................................ 11

7.2.1 General ..................................................................................................................................................................................... 11

7.2.2 Sessions ................................................................................................................................................................................... 11

7.2.3 Transport requirements ...........................................................................................................................................12

7.2.4 Response time-outs ......................................................................................................................................................12

7.2.5 Retransmission .................................................................................................................................................................12

7.2.6 Duplicate datagrams ....................................................................................................................................................12

7.3 General file procedures................................................................................................................................................................ 12

7.4 Sessions ......................................................................................................................................................................................................12

7.4.1 General .....................................................................................................................................................................................12

7.4.2 Establishing a session .................................................................................................................................................13

7.4.3 Maintaining a session ........................................................................................................................................... ....... 14

7.4.4 Terminating a session .................................................................................................................................................15

7.5 Requesting information .............................................................................................................................................................. 16

7.5.1 General ..................................................................................................................................................................................... 16

7.5.2 Offline subscriptions ................................................................................................................................................... 16

7.5.3 Online subscriptions .................................................................................................................................................... 16

7.6 Publication of information ........................................................................................................................................................ 17

7.6.1 General ..................................................................................................................................................................................... 17

7.6.2 General procedures ....................................................................................................................................................... 17

7.6.3 Single subscriptions ..................................................................................................................................................... 19

7.6.4 Registered subscriptions ......................................................................................................................................... 19

Annex A (normative) Message definition requirements .............................................................................................................21

Annex B (normative) Datagram structures ..............................................................................................................................................25

Annex C (normative) Data dictionary ..............................................................................................................................................................33

Annex D (normative) Value domains ................................................................................................................................................................64

Annex E (normative) TCP/UDP datagrams exchange implementation considerations .............................77

Annex F (normative) TCP/UDP datagrams exchange over internet protocols ....................................................78

iii
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ISO 14827-2:2022(E)

Annex G (normative) Protocol requirements list ...............................................................................................................................79

Bibliography .............................................................................................................................................................................................................................83

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ISO 14827-2:2022(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 204, Intelligent transport systems.

This second edition cancels and replaces the first edition (ISO 14827-2:2005), which has been technically

revised.
The main changes are as follows:
— the title has been modified;

— the concept of a platform-independent model (PIM) as defined in ISO/TS 19468 has been integrated;

— the message format previously defined in ISO 14827-1:2005 (to be withdrawn) has been included.

A list of all parts in the ISO 14827 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 14827-2:2022(E)
Introduction

Data exchange among centres is a baseline service for implementing intelligent transport system

(ITS) services. For interoperability purposes, data delivery and collaborative ITS services need to be

implemented according to certain specifications based on fully-described interfaces.

This document has been revised based on the concept of a platform-independent model (PIM) as

defined in ISO/TS 19468, maintaining backward compatibility with ISO 14827-2:2005 and taking into

consideration the future withdrawal of ISO 14827-1:2005.

The development of the first editions of ISO 14827-1 and ISO 14827-2 began in the 1990s. These

documents were published in 2005 based on European DATEX. Since then, the exchange environment

of traffic information and traffic data has made a great deal of progress and DATEX II has been

developed, enabling the distribution of traffic information and traffic management information

in a way that is not dependent on language and presentation format. DATEX II is closely related to

ISO/TS 19468. ISO/TS 19468 aims to describe the general exchange specification technology and to

describe interaction through a high-level model which is not dependent on a specific technology in a

model-driven approach; it defines functional exchange profiles by several possible exchange patterns.

According to this concept, ISO 14827-2 (this document) was revised as a platform-specific model for AP-

DATEX (application profile-data exchange) and other Internet protocol (IP) networks. The relationship

between ISO/TS 19468 and the ISO 14827 series (including this document) is shown in Figure 1. This

document aims to define and describe the data exchange requirements using TCP/UDP (transmission

control protocol/user datagram protocol) datagrams (defined as “DATEX-ASN”) and the basics of ASN.1

messages, as defined in ISO 14827-1.

This document is not intended to conflict with existing International Standards on interfaces of data

exchange among ITS centres.
Key
PIM platform-independent model
EP exchange pattern
FEP functional exchange profile
PSM platform-specific model
Figure 1 — Relationship between exchange-related documents
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INTERNATIONAL STANDARD ISO 14827-2:2022(E)
Intelligent transport systems — Data interfaces between
centres for transport information and control systems —
Part 2:
AP-DATEX
1 Scope

This document defines a platform-specific model (PSM) for data exchange, which specifically uses

ASN.1 and TCP/UDP (transmission control protocol/user datagram protocol) datagrams which were

defined as “DATEX-ASN” in the first edition of this document for AP-DATEX (application profile-data

exchange) and other Internet protocol (IP) networks. A PSM is an actual implementation of a platform-

independent model (PIM) for exchange. This document specifies the message rules and procedures for

communication between different systems for ITS using TCP/UDP datagrams.

This document deals mainly with the communication interfaces. It has been designed to meet the

unique requirements of intelligent transport systems (ITS). However, it has also been designed in a

generic fashion and thus can be used for other data exchanges as well.
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/TS 19468, Intelligent transport systems — Data interfaces between centres for transport information

and control systems — Platform-independent model specifications for data exchange protocols for

transport information and control systems

ISO/IEC 8824-1, Information technology — Abstract Syntax Notation One (ASN.1) — Part 1: Specification

of basic notation
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/TS 19468 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
DATEX-ASN

data exchange protocol in abstract syntax notation as TCP/UDP (transmission control protocol/user

datagram protocol) datagrams exchange

Note 1 to entry: This was initially defined in ISO 14827-2:2005 (first edition of this document).

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ISO 14827-2:2022(E)
3.2
DatexDatapacket

TCP/UDP (transmission control protocol/user datagram protocol) datagrams which are defined

in ASN.1 as application layer data packets and can be exchanged using any compatible lower-layer

combination
Note 1 to entry: See Annex B.
3.3
guaranteed delivery

TCP/UDP (transmission control protocol/user datagram protocol) datagrams exchange mechanism in

which the client acknowledges the receipt of a publication (reply)
3.4
heartbeat

data packet sent to indicate that the sending system is still alive and communicating

3.5
publication
information (usually contained in payload) exchange from a supplier
Note 1 to entry: “Payload publication” is defined in ISO/TS 19468.
3.6
subscription
request to a supplier from a client for information exchange
3.7
transport profile

set of services which are responsible for providing a virtually error-free, point-to-point connection so

that host A can send data packets to host B and they will arrive uncorrupted
4 Symbols and abbreviated terms
AP-DATEX application profile-data
BER basic encoding rule
CORBA common object request broker architecture
DATEX-ASN data exchange in abstract syntax notation
DTLS datagram transport layer security
EDIFACT electronic data interchange for administration, commerce and transport
EP exchange pattern
FDDI fibre distributed data interface
FEP functional exchange profile
FrED friendly exchange of data
FTP file transfer protocol
IP Internet protocol
ISDN integrated services digital network
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ISO 14827-2:2022(E)

NTCIP National Transportation Communications for ITS (intelligent transport systems)

OID object identifier
PIM platform-independent model
PN port number
PPP point-to-point protocol
PRL protocol requirements list
PSM platform-specific model
SNMP simple network management protocol
TCP transmission control protocol
TCIP transit communications interface profiles
TFTP trivial file transfer protocol
TICS transport information and control systems
TLS transport layer security
UDP user datagram protocol
VMS variable message sign
5 Conformance

There is no explicit conformance test in this document. Conformance is achieved if the exchange data

conform to the messaging rules of this document.
6 Exchange framework
6.1 General

TCP/UDP datagrams exchange allows different systems to exchange relevant data. The data are

contained in end-application messages. Each end-application message shall be defined according

to message definition requirements laid out in Annex A. TCP/UDP datagrams exchange defines how

these end-application messages are packaged to form complete datagrams and also defines the rules

and procedures for exchanging these datagrams. Systems using TCP/UDP datagrams exchange may

implement additional end-application functionalities according to the user requirements.

A TCP/UDP datagrams exchange network comprises a certain number of systems, an example of which

is provided in Figure 2. It is typically exchanged using well-known IPs, such as UDP/IP or TCP/IP, then

may use IPsec, DTLS, TLS, etc. for security.
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ISO 14827-2:2022(E)
Key
1 weather system 4 emergency management system
2 traffic management system 5 information service provider
3 transit management system
Figure 2 — An example of TCP/UDP datagrams exchange network
Each system can be viewed as consisting of the interfaces, as shown in Figure 3.
Key
1 application interface 5 communications cloud
2 operator interface 6 client system
3 communication interface 7 supplier system
4 database interface
Figure 3 — System interfaces
The data exchange environment and actors can be viewed as shown in Figure 4.
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ISO 14827-2:2022(E)
Figure 4 — Communication interfaces

Systems implementing this document sometimes operate simultaneously as a client and supplier, using

multiple sessions. The communications cloud between the two systems can be complex or simple.

When implementing a specific PSM, a functional exchange profile (FEP), which is a selection of data

exchange features, is identified.
The model driven approach defined in ISO/TS 19468 is summarized in Figure 5.
Figure 5 — Business scenario and functional exchange profile (FEP)

This document describes the mapping rules in order to implement specific platform push and pull and

FEP+EP based PIM in TCP/UDP datagrams exchange which is based on ASN.1 message PSM. A PIM-level

description of FEP+EP is detailed in ISO/TS 19468 and is referenced in this document.

6.2 Basic pull with TCP/UDP datagrams exchange PSM
6.2.1 Overview

The basic pull EP+FEP is based on an information request by a client from a supplier which delivers

requested information to the client. It can be implemented in IPs. A selection of features for basic pull is

shown in Table 1.
Table 1 — Selection of features for basic pull
Features area Feature Basic pull implemented
Subscription contract Contract Log in/Log out
See 7.4.2, 7.4.4
Catalogue N
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ISO 14827-2:2022(E)
TTabablele 1 1 ((ccoonnttiinnueuedd))
Features area Feature Basic pull implemented
Session Session life cycle Log in/Log out/Maintain
See 7.4.2, 7.4.4, 7.4.3
Link monitoring N
Information management Operating modes Periodic or on occurrence
(i.e. triggered by client conditions)
Update methods N
Life cycle management N
Data delivery Data delivery Y
Data request Y
Large datasets handling Y
Synchronization Y
(periodic mode)
Self-description Handshake N
Communication Security N
Compression N
Communication N
6.2.2 Exchange pattern messages definition
6.2.2.1 Overall presentation

Exchange systems are used which provide tools enabling message generation and their transfer

between supplier and client. A data flow between the supplier system and client system is shown in

Figure 6.
Figure 6 — Basic pull exchange actors
6.2.2.2 Exchange pattern definition

The basic pull client and supplier shall establish, maintain, or terminate a session according to the

procedure described in 7.4 of this document.

The basic pull client shall request information according to the procedure described in 7.5 of this

document.

The basic pull supplier shall provide information according to the procedure described in 7.6 of this

document.
6.2.2.3 Relevant exchange information in exchange data model

No exchange information is needed in this pattern to implement data delivery features.

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ISO 14827-2:2022(E)
6.2.2.4 Exchange messages
Exchange messages are included in the payload and defined in Annex B.
6.2.3 State diagrams

State diagrams are not needed, and relevant procedures are described in Clause 7.

6.2.4 Features implementation description
6.2.4.1 Overview

This subclause provides a description and the corresponding specification for each feature identified

in the context diagram according to the basic pull exchange architecture. The following features are

specified:
— subscription contract;
— subscription (also known as session);
— information management;
— data delivery;
— communication/protocol.
6.2.4.2 Subscription contract
6.2.4.2.1 Contract

The session is established or terminated according to the procedure described in 7.4.

6.2.4.2.2 Catalogue
Catalogue is not managed.
6.2.4.3 Session
6.2.4.3.1 Session life cycle
The session is managed according to the procedure described in 7.4.
6.2.4.3.2 Link monitoring
Link monitoring is not provided.
6.2.4.4 Information management
6.2.4.4.1 Operating modes

The available operating mode for client pull is periodic, or on occurrence as described in 7.6.

6.2.4.4.2 Update methods
The update method is not provided.
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ISO 14827-2:2022(E)
6.2.4.4.3 Life cycle management
The life cycle is not managed.
6.2.4.5 Data delivery
6.2.4.5.1 Data delivery scheme
The data delivery scheme is described in 7.6.
6.2.4.5.2 Data request scheme
The data request scheme is described in 7.5.
6.2.4.5.3 Large datasets handling

The large datasets are handled as a data file. The data file scheme is described in 7.6.

6.2.4.5.4 Synchronization

Under periodic mode, publication cycle synchronization is available, and its scheme is described in 7.6.4.

6.2.4.6 Self-description
Handshake is not available.
6.2.4.7 Communication
Communication feature may be implemented at IP level.
6.2.4.8 General optimization issues

Implementation considerations and IP usages for TCP/UDP datagrams exchange shall be as shown in

Annex E and Annex F. Requirements of protocol shall be as shown in Annex D.
6.3 Basic push TCP/UDP datagrams exchange PSM
6.3.1 Overview

The basic push EP+FEP is performed from a supplier which delivers information to a client without

request by the client. It can be implemented in internet protocols. A selection of features for basic push

is shown in Table 2.
Table 2 — Selection of features for basic push
Features area Feature Basic push implemented
Subscription contract Contract Log in/Log out
See 7.4.2, 7.4.4
Catalogue N
Session Session life cycle Log in /Log out/Maintain
See 7.4.2, 7.4.4, 7.4.3
Link monitoring N
Information management Operating modes Periodic or on occurrence
(i.e. triggered by supplier conditions)
Update methods N
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ISO 14827-2:2022(E)
TTabablele 2 2 ((ccoonnttiinnueuedd))
Features area Feature Basic push implemented
Life cycle management N
Data delivery Data delivery Y
Data request N
Large datasets handling Y
Synchronization Y
(periodic mode)
Self-description Handshake N
Communication Security N
Compression N
Communication N
6.3.2 Exchange pattern messages definition
6.3.2.1 Overall presentation

Exchange systems are used which provide tools enabling message generation and their transfer

between supplier and client. A data flow between supplier and client is shown in Figure 7.

Figure 7 — Basic push exchange actors
6.3.2.2 Exchange pattern definition

The basic push client and supplier shall establish, maintain, or terminate a session according to the

procedure described in 7.4 of this document.

The basic push supplier may request receiving information to client and shall provide information

according to the procedure described in 7.6 of this document.
6.3.2.3 Relevant exchange information in exchange data model

No exchange information is needed in this pattern to implement data delivery features.

6.3.2.4 Exchange messages
Exchange messages are included in payload and defined in Annex B.
6.3.3 State diagrams
State diagrams are not needed, and procedures are described in Clause 7.
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ISO 14827-2:2022(E)
6.3.4 Features implementation description
6.3.4.1 Overview

This subclause provides a description and the corresponding specification for each feature identified

in the context diagram, according to the basic pull exchange architecture. The following features are

specified:
— subscription contract;
— subscription (also known as session);
— information management;
— data delivery;
— communication/protocol.
6.3.4.2 Subscription contract
6.3.4.2.1 Contract

The session is established or terminated according to the procedure described in 7.4.

6.3.4.2.2 Catalogue
Catalogue is not managed.
...