ISO 17438-5:2025

Overview

ISO 17438-5:2025 - "Intelligent transport systems - Indoor navigation for personal and vehicle ITS stations - Part 5" specifies requirements and message structures to support central ITS station (C-ITS-S) based (server‑based) indoor positioning. It focuses on the core flow between a personal/vehicle ITS station (P/V‑ITS‑S) and a C‑ITS‑S for delivering indoor navigation functionality. The document defines use cases, message flows (notably get-positions and candidate-positions), ASN.1 data types and an ASN.1 module (Annex A and Annex B), and conformance rules for mandatory/optional/conditional fields.

Key topics and requirements

• Purpose: Enable server-based indoor positioning where the C‑ITS‑S computes a device’s position on request - useful because GNSS signals are generally unavailable indoors.
• Use case: UC - Server based positioning (ISO 17438-1 reference); pre‑conditions include bi‑directional communication and appropriate access permission for the P/V‑ITS‑S.
• Message flow:
  • get-positions: P/V‑ITS‑S sends scanned resources (e.g., Wi‑Fi, BLE, cellular measurements) to the C‑ITS‑S.
  • candidate-positions: C‑ITS‑S returns calculated possible positions; the P/V‑ITS‑S selects the most likely position for navigation.
• Message and data model:
  • Definitions use ASN.1 conventions; normative data types and code lists are in Annex A and ASN.1 schema in Annex B.
  • Fields are categorized as mandatory, optional or conditional; implementations must respect multiplicity and conformance rules.
• Scope limits: The standard intentionally excludes authorization/security, payment, indoor map/data preparation, and low‑level transport protocols - it addresses only the core application‑level flow for C‑ITS‑S based positioning.

Applications and who uses it

• Primary users:
  • ITS architects and system integrators designing server-based indoor positioning services.
  • Developers of C‑ITS‑S platforms and P/V‑ITS‑S client applications (mobile apps, vehicle systems, robots).
  • Location service providers, airports, malls, public transport hubs and facility managers integrating indoor navigation into ITS ecosystems.
• Practical applications:
  • Vehicle and pedestrian indoor navigation inside terminals, parking garages, and large venues.
  • Fleet management and indoor routing for service robots or logistics vehicles.
  • Interoperable positioning services where centralized computations simplify client devices and protect indoor reference datasets.

Related standards

• ISO 17438-1: General information and use case definition for indoor navigation.
• ISO 17438-4 (references): Definitions for server-based/indoor positioning concepts.
• ISO 13184-2: Related ITS guidance protocol references.

Keywords: ISO 17438-5:2025, indoor navigation, central ITS station, C-ITS-S, server-based positioning, get-positions, candidate-positions, ASN.1, P/V‑ITS‑S, ITS station.