ISO 15784-3:2008

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 <NULL> 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.