ISO 15628:2013

Overview - ISO 15628:2013 (DSRC application layer)

ISO 15628:2013 defines the application layer core for Dedicated Short Range Communication (DSRC) within Intelligent Transport Systems (ITS). It specifies a lightweight, real‑time oriented “application layer” that provides reusable communication tools (kernels) to support DSRC applications running on on‑board units (OBUs) and road‑side units (RSUs). The standard focuses on application-layer services and intermediate OSI functionality required for reliable short‑range ITS messaging - it does not define application data content or an overall security policy.

Key topics and technical requirements

ISO 15628 structures the DSRC application layer into modular kernels and prescribes their behavior and service primitives:

• Application layer structure and framework

  • Core components: Transfer kernel (T‑Kernel) plus Initialisation kernel (I‑Kernel) and/or Broadcast kernel (B‑Kernel).
  • Relationship to DSRC data link and physical layers; supports extensibility for different lower‑layer services and application interfaces.

• Transfer services and primitives

  • Standardized services: GET, SET, ACTION, EVENT‑REPORT, enabling read/write, remote operations and event notifications between peers.
  • Use of T‑APDUs and ASN.1/PER encoding to move application objects.

• Multiplexing, fragmentation and concatenation

  • Procedures for application multiplexing (serving multiple apps in one OBU), fragmentation to map large ASDUs over multiple link SDUs, and concatenation/chaining for efficient delivery.

• Encoding rules and data structures

  • Specifies use of ASN.1 abstract syntax with Packed Encoding Rules (PER) (see ISO/IEC 8824‑1 and ISO/IEC 8825‑2).
  • Normative annexes define data structures, naming/registration and feature declarations.

• Initialization, broadcast and management

  • Communication initialization/release procedures, broadcast service support, and DSRC management including communication profile handling.
  • Note: ISO 15628 provides transport mechanisms for security‑related data but does not define a security policy; also, the “broadcast pool” is noted as untested.

Practical applications and typical users

ISO 15628 is intended for practitioners who implement or integrate DSRC communications in ITS environments:

• OBU and RSU manufacturers implementing the application layer kernels and T‑APDU handling.
• ITS software developers and system integrators building V2I and short‑range V2X services that require standardized transfer, fragmentation and multiplexing.
• Test labs and certification bodies verifying conformance to DSRC application‑layer behavior.
• Traffic authorities and ITS architects specifying interoperable roadside and in‑vehicle communication profiles.

Keywords: ISO 15628, DSRC application layer, ITS, transfer kernel, ASN.1 PER, fragmentation, concatenation, multiplexing, OBU, RSU, V2I.

Related standards

• ISO/IEC 8824‑1 (ASN.1 abstract syntax)
• ISO/IEC 8825‑2 (PER encoding rules)
• ISO/IEC 7498‑1 (OSI Basic Reference Model)
• ISO 14906 (example ActionType reference) These references provide the encoding, OSI context and protocol examples used by ISO 15628.