ISO/TR 21735:2019

Overview

ISO/TR 21735:2019 - "Intelligent transport systems - Framework architecture for plug and play (PnP) functionality in vehicles utilizing nomadic devices" - defines a framework architecture and information-exchange model for vehicles that support plug-and-play (PnP) devices. The technical report addresses bidirectional communication between a PnP vehicle and occupants’ nomadic devices (e.g., smartphones, wearables), with the primary goal of improving occupant convenience and the vehicle/occupant safety state by sharing device, sensor and occupant status.

Key topics and technical requirements

• Framework architecture for in‑vehicle PnP
  • A PnP layer/gateway abstracts hardware (sensors, actuators, communication modules) from applications to allow attaching, switching and updating devices before and after market.
• Information representation
  • Defines representation of vehicle safety/availability states and occupant status (driver info, health, authentication).
• Information transmission logic
  • Bidirectional flows: vehicle → nomadic device (device status, sensor data, communication capability) and occupant → vehicle (identification, input, health/status).
  • Periodic monitoring and event-driven updates via the PnP gateway.
• Device classes covered
  • Sensors (radar, lidar, camera), mechanical systems (steering, braking, ECUs), and communication devices (WLAN, Bluetooth, V2X).
• Safety-state effects
  • How changes in device availability or occupant condition affect vehicle safety state and automated responses.
• Use cases (illustrative)
  • Acceptance/denial of service usage, ownership exchange, suggesting an optimum functional package, and mandatory operation of functional packages.

Practical applications and users

Who benefits:

• Automotive OEMs and tier‑1 suppliers - designing modular vehicle platforms that support after‑market upgrades and flexible feature sets.
• Software and app developers - building nomadic-device applications that report occupant state and present vehicle capabilities to users.
• System integrators and cybersecurity teams - implementing secure PnP gateways and safe message flows between devices and occupants.
• Regulators and safety engineers - assessing how device changes impact vehicle safety state and human‑vehicle interaction.

Practical uses:

• Rapid prototyping of new sensor-based functions without deep rework of vehicle software.
• Personalization: nomadic device transmits driver preferences and health status to adapt vehicle behavior.
• After-market upgrades: swapping sensors or communication modules while preserving interoperability and safety signaling.

Related standards

• ISO 17419 - Globally unique identification (referenced)
• ISO 17423 - Cooperative systems application requirements (referenced)
• ISO 21217 - CALM communications architecture (referenced)

Keywords: ISO/TR 21735:2019, plug and play, PnP vehicle, nomadic devices, intelligent transport systems, vehicle architecture, in-vehicle PnP, vehicle-occupant communication, safety state, vehicle sensors.