Overview - ISO 21219-3:2019 (TPEG2-UBCR)
ISO 21219-3:2019, titled Intelligent transport systems - Traffic and travel information (TTI) via transport protocol experts group, generation 2 (TPEG2) - Part 3: UML to binary conversion rules (TPEG2‑UBCR), defines how TPEG2 applications modelled in UML are converted into the TPEG binary format. The standard separates semantics (UML application models) from physical format representations, providing a repeatable, tool-friendly rule set to produce a binary representation for Traffic and Travel Information (TTI) applications.
Key topics and technical requirements
- UML to binary conversion rules: Normative rules for converting UML classes, attributes and relationships into the binary encoding required by TPEG2.
- Binary format description: Required structure for the binary-format annex in application specifications, including Introduction, Application framing and signalling, Application components, and Application datastructures.
- Abstract data types: Binary definitions for the abstract data types specified in ISO 21219‑2 are provided and must be followed when encoding.
- Compound data types: Specific rules for converting classes, data structures, selectors and attribute multiplicities (single, optional, repeating) into binary.
- Application framing & signalling: Rules for Application Identifier (AID), version number signalling (major/minor), and selection of the appropriate Service Component Frame type for transmission.
- Component IDs and TPEG tables: Guidance for assigning unique component IDs for UML classes (excluding those stereotyped as >) and representing TPEG tables in binary.
- Robustness features: Use of a binary component structure to detect and skip unknown content (see Annex A), aiding forward/backward compatibility.
- Normative references: Works in conjunction with ISO 21219‑2 (UML modelling rules), ISO 21219‑5 (service framework) and IEEE/ISO floating-point rules where applicable.
Practical applications and target users
ISO 21219-3 is intended for:
- ITS architects and system designers creating TPEG2 traffic and travel information services.
- Application developers and tool vendors implementing automated conversion tools (UML XMI → TPEG binary).
- Broadcasters, telematics and navigation vendors, automotive OEMs and mobile content providers who encode, transmit or decode TTI messages.
- Standards and compliance teams preparing application specification annexes for TPEG binary deployment.
Practical benefits include consistent binary encoding, multi-format interoperability (binary + XML), easier maintenance of application semantics, and improved compatibility across service versions and decoders.
Related standards
- ISO 21219‑2 - TPEG2 UML modelling rules (normative companion)
- ISO 21219‑5 - TPEG2 Service framework (framing and SC types)
- ISO/IEC/IEEE 60559 - Floating‑point arithmetic (used where numeric types apply)
Keywords: ISO 21219-3:2019, TPEG2, UML to binary conversion, TPEG binary format, traffic and travel information, ITS, UML modelling, application framing.