Overview
ISO/TR 17384:2008 is a Technical Report from ISO/TC 204 covering the air interface message set, contents and format for Interactive Centrally Determined Route Guidance (CDRG) systems. It specifies the message-level information exchanged between road-side infrastructure and in-vehicle units (IVUs) so that recommended routes (route objects), travel-time predictions and related guidance can be delivered to vehicles. The report is informative (a Technical Report) and is media independent, addressing both beacon/DSRC (dedicated short‑range communications) and cellular phone based CDRG deployments. It applies to vehicles with onboard map databases as well as simpler units that only support text or basic graphic displays.
Key topics and technical requirements
- Air interface message set: Defines the types of messages, their purpose and the contents required for delivering recommended routes and related information over the downlink/uplink.
- Media independence: Message definitions account for both DSRC/beacon-based and cellular phone-based communications, noting practical differences (e.g., latency and connection time).
- Support for map/no‑map IVUs: Message contents accommodate vehicles with full onboard map databases and those without (using connecting‑network info, simplified graphics or text).
- Route object concept: Recommended routes are sent as route objects that IVUs use to display routes or generate turn-by-turn instructions - how they are rendered onboard is left to implementers.
- Message size and efficiency: Message sizes are defined with reference to existing in-vehicle communication requirements to optimize bandwidth and efficiency.
- Operational goals and functions: Describes interactive two‑way communication, OD (origin-destination) data collection, traffic assignment objectives, and multi‑mode guidance interactions with LDRG/SRG (locally/static determined route guidance).
- Implementation guidance: Informative annexes (e.g., case studies such as Japan) illustrate practical realization and deployment considerations.
Applications and who uses it
- Traffic management centers and service providers: For centrally calculating recommended routes and delivering them to vehicles.
- Automotive OEMs and IVU manufacturers: To implement interoperable message handling and route object processing in navigation systems.
- Telecom and roadside-equipment vendors: For DSRC/cellular interface design and message transport considerations.
- ITS integrators and system architects: When designing multi‑mode route guidance that combines CDRG with LDRG/SRG.
- Standards bodies and implementers: As a reference for harmonizing message sets across service areas and reducing fragmentation.
Related standards
- ISO/TC 204 Intelligent Transport Systems (general committee)
- Referenced guidance: “In‑vehicle Navigation Systems Communication Device Message Set Requirements” (used to dimension message sizes)
- Complementary ITS and DSRC/cellular specifications for physical and transport layers
Keywords: ISO/TR 17384:2008, CDRG, interactive centrally determined route guidance, air interface message set, intelligent transport systems, DSRC, cellular CDRG, in-vehicle unit, route object, ITS interoperability.