Overview
ISO/TR 24935:2025 - Road vehicles - Software update over the air using mobile cellular network - is a technical report that documents use cases, reference models and operational activities for performing vehicle software updates over the air (OTA) via mobile cellular networks. It provides a practical case study showing how international standards can be applied to prepare software update packages (SUPs), manage update infrastructure, and operate update procedures inside vehicles. The report also describes metadata models, a cybersecurity model, and verification/validation activities for OTA update processes.
Key Topics
- Reference model and metadata for organizing software update operations and SUP content.
- SUP format and contents, including:
- Target vehicle and ECU resolution
- Vehicle state requirements for successful installation
- Compatibility and dependency information between ECUs
- User interaction and installation/activation prerequisites
- Cybersecurity model with cryptography use and cryptographic key management considerations.
- Infrastructure functions: update server architecture, cybersecurity checks, target resolution, failure handling and use of mobile cellular networks for delivery.
- Operational flows: uploading/storing SUPs, resolving recipients, verifying vehicle communication interfaces (VCIs), transferring packages and collecting results, and managing update campaigns.
- In-vehicle procedures: EE (electrical/electronic) architecture overview, installation and activation flows, redundant flash bootloader behavior, and fail-recovery.
- Vehicle communications: generic Ethernet protocols and specific mechanisms such as UDSonIP over AVTP for in-vehicle update transport.
- Evaluation metrics: transmission speed, successful transfer rates and overall evaluation of software update operation.
- Informative annex material (e.g., KMIP request/response example).
Applications
ISO/TR 24935:2025 is aimed at practitioners implementing OTA vehicle software update systems and those integrating standards into operational processes:
- OEMs and Tier‑1 suppliers designing OTA update infrastructure and SUPs
- Telematics and connectivity providers delivering updates over mobile cellular networks
- Cybersecurity teams specifying cryptographic measures and key management for OTA
- Fleet operators and service organizations managing large-scale update campaigns
- Test labs and validation engineers evaluating update performance and resilience
Related standards
- ISO 24089 - Road vehicles - Software update engineering (normative reference)
- ISO/IEC 8802-3 - Ethernet (referenced for in-vehicle communications)
- Relevant ISO/IEC terminology sources (ISO Online Browsing Platform, IEC Electropedia)
Keywords: ISO/TR 24935:2025, OTA, software update over the air, mobile cellular network, vehicle software update, SUP, ECU, cybersecurity, key management, UDSonIP, AVTP.