ISO 15784-3:2008

Intelligent transport systems (ITS) - Data exchange involving roadside modules communication - Part 3: Application profile-data exchange (AP-DATEX)

ISO 15784-3:2008 defines an application profile referring ISO 14827 and other base standards. The application profile it specifies is used to exchange data and messages between a traffic management centre and roadside modules for traffic management, and between roadside modules used for traffic management. The scope of ISO 15784-3:2008 does not include the communication between roadside modules and in-vehicle units, in-vehicle communication, in-cabinet communication or motion video transmission from a camera or recorded media.

Systèmes intelligents de transport (SIT) — Échange de données impliquant la communication par modules en bordure de route — Partie 3: Profil d'application-échange de données (AP-DATEX)

General Information

• Status: Published
• Publication Date: 05-Oct-2008
• ICS: 03.220.20 - Road transport
• 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: 9093 - International Standard confirmed
• Start Date: 06-Nov-2024
• Completion Date: 13-Dec-2025

Overview

ISO 15784-3:2008 - Application profile‑data exchange (AP‑DATEX) - is part of the ISO 15784 series for Intelligent Transport Systems (ITS). It defines an application profile that specifies how to exchange structured traffic management data and messages between a traffic management centre and roadside modules, and between roadside modules themselves. AP‑DATEX references DATEX‑ASN (ISO 14827-2) and presentation encoding rules (ISO/IEC 8825‑1) to standardize message formats and encoding. The scope excludes in‑vehicle communication, in‑cabinet links, video streaming and roadside-to-in-vehicle exchanges.

Key topics and requirements

• Application profile definition: Specifies use of base standards to implement the application, presentation and session layers for roadside module data exchange (AP‑DATEX).
• Base standards referenced: ISO 14827‑2 (DATEX‑ASN) for application semantics and ISO/IEC 8825‑1 (Basic Encoding Rules) for presentation/encoding.
• OSI layer mapping: Focus on the top three OSI layers - application (DATEX‑ASN), presentation (ASN.1 encoding rules) and session (defined as because application handles session functionality).
• Functional constraints:
  • Designed for large, relatively fixed‑structure data exchanges.
  • Deterministic real‑time behaviour is not required; emphasis is on efficient, reliable data exchange rather than hard real‑time guarantees.
  • Suitable where roadside modules have advanced functions and may act as peers with the centre and each other.
• Transport independence: AP‑DATEX does not mandate lower‑layer transport - countries or projects define transport profiles (routing, segmentation, error handling) suited to local infrastructure.
• Conformance and compatibility: Annex A contains a DATEX‑ASN profile requirement list (normative) and Annex B provides guidance on compatibility with other profiles (informative).

Applications

• Standardizes messaging between traffic management centres and devices like signal controllers, dynamic message signs and vehicle detectors.
• Enables roadside module-to-roadside module coordination for distributed traffic control and status reporting.
• Useful for data exchange scenarios that require structured traffic data, such as congestion reports, signal plans, detector data and signage updates - where message structure and interoperability are primary concerns.

Who should use this standard

• Traffic authorities and transport agencies specifying ITS interfaces
• ITS system integrators and architects designing centre-to-roadside communications
• Roadside equipment manufacturers implementing DATEX‑ASN message support
• Standards bodies and consultants creating national transport profiles

Related standards

• ISO 14827‑2 (DATEX‑ASN) - application data definitions
• ISO/IEC 8825‑1 - ASN.1 Basic Encoding Rules
• ISO/IEC TR 10000 series - profile framework and taxonomy

Keywords: ISO 15784-3:2008, AP‑DATEX, DATEX‑ASN, intelligent transport systems, roadside modules, data exchange, traffic management centre, ASN.1, ITS application profile.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15784-3
First edition
2008-10-15
Intelligent transport systems (ITS) — Data
exchange involving roadside modules
communication —
Part 3:
Application profile-data exchange
(AP-DATEX)
Systèmes intelligents de transport (SIT) — Échange de données
impliquant la communication par modules en bordure de route —
Partie 3: Profil d'application-échange de données (AP-DATEX)

Reference number
©
ISO 2008
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ii © ISO 2008 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Abbreviated terms . 4
5 General. 5
5.1 Open systems interconnection (OSI) reference model. 5
5.2 Scenario. 5
6 Requirements . 7
6.1 General Requirements. 7
6.1.1 Stack definition . 7
6.1.2 Optional features . 7
6.1.3 Compatibility . 7
6.2 Application layer requirements . 7
6.3 Presentation layer requirements. 7
6.4 Session layer requirements. 7
6.5 Transport layer requirements. 7
Annex A (normative) Application profile for DATEX-ASN profile requirement list . 8
Annex B (informative) Compatibility with other application profiles. 14
Bibliography . 15

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 15784-3 was prepared by Technical Committee ISO/TC 204, Intelligent transport systems.
ISO 15784 consists of the following parts, under the general title Intelligent transport systems (ITS) — Data
exchange involving roadside modules communication:
⎯ Part 1: General principles and documentation framework of application profiles
⎯ Part 3: Application profile-data exchange (AP-DATEX)

iv © ISO 2008 – All rights reserved

Introduction
The functional requirements for communication between a traffic management centre and roadside modules
used for traffic management are varied because internationally there are many kinds of roadside modules for
traffic management, such as signal controllers, dynamic message signs and vehicle detectors. In the
development of standards for data exchanges between a traffic management centre and roadside modules
used for traffic management, ISO/TC 204/WG9 agreed that the concept of a single standard for all countries
and devices might not be appropriate, but a set of standards for different types of roadside module might be
more appropriate.
As a result, ISO/TC 204/WG9 adopted the philosophy of producing profile documents to specify how data
should be exchanged.
In the development of this part of ISO 15784, reference was made to the existing standards about profiles,
specifically NTCIP 8003 which is the US standard for a profile framework, and ISO/IEC TR 10000, which is a
series of Technical Reports under the general title Information technology — Framework and taxonomy of
International Standardized Profiles.
The purpose of a profile is to specify the use of one or more base standards to provide a requested function.
Because there are multiple functional requirements to data exchange between a centre and the roadside
modules, ISO 15784 defines multi-part profiles.
This part of ISO 15784 defines only the application profile. End application data is defined in the data-registry.
Each country should define lower layer profiles based on the internationally standardized protocols because
each country has its own circumstance on communication infrastructure.

INTERNATIONAL STANDARD ISO 15784-3:2008(E)

Intelligent transport systems (ITS) — Data exchange involving
roadside modules communication —
Part 3:
Application profile-data exchange (AP-DATEX)
1 Scope
The purpose of this part of ISO 15784 is to define an application profile referring ISO 14827 and other base
standards.
The application profile specified in this part of ISO 15784 is used to exchange data and messages in the
following cases.
a) Between a traffic management centre and roadside modules for traffic management.
b) Between roadside modules used for traffic management.
The scope of this part of ISO 15784 does not include the communication between roadside modules and in-
vehicle units, in-vehicle communication, in-cabinet communication or motion video transmission from a
camera or recorded media.
2 Normative references
The following referenced documents are indispensable for the application 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 8825-1:2002, Information technology — ASN.1 encoding rules: Specification of Basic Encoding
Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER) — Part 1
ISO/IEC TR 10000-2:1998, Information technology — Framework and taxonomy of International Standardized
Profiles — Part 2: Principles and Taxonomy for OSI profiles
ISO 14827-2:2005, Transport information and control systems — Data interfaces between centres for
transport information and control systems — Part 2: DATEX-ASN
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
application layer
layer containing all functions needed for the distributed applications and not already provided by the
presentation service
NOTE The application layer constitutes layer 7 of the OSI model.
3.2
base standard
approved international standard or a related authoritative standard
3.3
Basic Encoding Rules
BER
standardized determination of data encoding to conform to the requirements of ISO 8824, ASN.1
NOTE The Basic Encoding Rules are given in ISO 8825.
3.4
centre
computer or network that is required to meet a standardized communications interface over a fixed-point
communications network, regardless of whether it is the only system within the building or just one of many, or
even if it is located in the field
3.5
client
computer or application which requests and accepts data from a server computer or application using some
kind of protocol
3.6
compatibility
capability of two or more items or components of equipment or material to exist and/or function in the same
system or environment without modification, adaptation or mutual interference
3.7
data
information before it is interpreted
3.8
datagram
a self-contained unit of data transmitted independently of other datagram
3.9
data link layer
layer that manages frames and performs error detection and correction
NOTE The data link layer constitutes layer 2 of the OSI model. It can also be used to co-ordinate distribution of
physical connections.
3.10
data packet
entity of data that can be sent between end-application systems in order to exchange information
NOTE A data packet relates to the application layer of the OSI stack and may be broken into several pieces by lower
layer protocols.
3.11
encoding rules
rules which specify the representation during transfer of the values of ASN.1 types
NOTE Encoding rules also enable the values to be recovered from the representation, given knowledge of the type.
3.12
end-application
process or program using the communications stack
2 © ISO 2008 – All rights reserved

3.13
intelligent transport systems
major national initiative to improve information, communication and control technologies in order to improve
the efficiency of surface transport
3.14
internet protocol
network protocol offering a connectionless mode network service in the internet suite of protocols
3.15
message
set of data grouped together for transmission
3.16
network layer
layer that provides functional and procedural means of transferring variable length data sequences from a
source to a destination
NOTE The network layer constitutes layer 3 of the OSI model.
3.17
open systems interconnection
OSI
reference model developed by ISO to enable different or similar systems to dialogue with one another
NOTE 1 This model constitutes a reference framework for describing data exchanges. Each layer performs a service at
the request of the adjacent higher layer, and in turn, requests more basic services from the lower layers. It is described in
7 layers.
NOTE 2 Open systems interconnection (OSI) is an international effort to facilitate communications among computers of
different manufacture and technology.
3.18
physical layer
layer that defines the physical data transmission medium
NOTE The physical layer constitutes layer 1 of the OSI model.
3.19
port
logical channel in a communications system
NOTE UDP and TCP use port numbers to multiplex data packets from a variety of applications onto a single
communications system.
3.20
port number
identifier of an application-entity to a transport service in the internet suite of protocols
NOTE The concept of port numbers is often present in OSI literature; however, port numbers are not inter-network
standardized, but exist as local network conventions only.
3.21
presentation layer
layer that converts data using different syntax
NOTE The presentation layer constitutes layer 6 of the OSI model.
3.22
profile
standard that defines rules by only combining requirements of other standards
NOTE An application profile is a profile that specifies the application, presentation, and session layers by referencing
a group of other standards.
3.23
roadside modules
terminal units controlled or monitored by a traffic management centre
NOTE Roadside modules are usually installed at the roadside arena.
3.24
server
computer or application which receives and responds to requests for data from client computers or
applications using some kind of protocol
3.25
session layer
layer that manages the dialogue between end-user application processes including restart, termination, and
checkpointing
NOTE The session layer constitutes layer 5 of the OSI model.
3.26
transport layer
layer that provides transparent transfer of data between end users
NOTE The transport layer constitutes layer 4 of the OSI model.
3.27
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
NOTE Connection-oriented transport profiles can also ensure that the data packets arrive in the correct order.
4 Abbreviated terms
AP Application Profile
ASN.1 Abstract Syntax Notation One
ATM Asynchronous Transfer Mode
DATEX-ASN Data Exchange in ASN.1
FHWA Federal Highway Administration
FDDI Fiber Distributed Data Interface
FSK Frequency Shift Keying
FTP File Transfer Protocol
IEC International Electro-technical Commission
4 © ISO 2008 – All rights reserved

ISO International Organization for Standardization
OSI Open Systems Interconnection
PICS Profile Implementation Conformance Statement
PMPP Point to Multi Point Protocol
PPP Point-to-Point Protocol (RFC 1661)
SFMP Simple Fixed Message Protocol
SLIP Serial Line Internet Protocol
SNMP Simple Network Management Protocol (RFC 1157)
SONET Synchronous Optical Network
STMF Simple Transportation Management Framework
STMP Simple Transportation Management Protocol
TCP Transmission Control Protocol (RFC 793)
TFTP Trivial File Transfer Protocol
TMP Transportation Management Protocols
TR Technical Report
UDP User Datagram Protocol (RFC 768)
5 General
5.1 Open systems interconnection (OSI) reference model
The OSI reference model defines seven layers, each performing a particular role in the transmission of data
over a medium. Application profiles define the upper three layers.
The top layer of the OSI seven layer model, the application layer, handles issues like network transparency,
resource allocation and problem partitioning. The application layer is concerned with the user's view of the
network.
The second highest layer in the OSI seven layer model, also known as layer 6 or the presentation layer,
performs functions such as text compression, code conversion, or format conversion to try to smooth out
differences between hosts.
Layer 5, the session layer, handles security and creation of the session.
5.2 Scenario
AP-DATEX should be used when there are connections between a traffic management centre and roadside
modules used for traffic management.
This part of ISO 15784 deals with the interface described in Figure 1.
Figure 1 — Example of the ISO 15784-3 AP-scerario
The definition of application profiles and their functions and responsibilities are defined in
ISO/IEC TR 10000-2:1998, 5.5.3. This profile references ISO standards for the application and presentation
layers of the OSI reference model. The session layer is defined as being 〈NULL〉 because the selected
...