Major upgrade! UIC is delighted to announce that the third edition of the International Railway Solution IRS 90940 has been published under the title “SFERA Protocol: Train Operation Data Exchange with On-Board Devices”. As can be seen from the title change, the scope and functionalities have been extended to include more than just Driver Advisory System (DAS) functions.
So, what’s new? The third edition of IRS 90940 isn’t simply an update; it has a full set of new features. Here’s what makes this release a must-read for rail professionals, engineers, and enthusiasts alike:
1. SFERA goes multi-function: beyond DAS
No longer limited to DAS, SFERA is now a universal protocol for train operation data exchange. This evolution supports Digital Instructions (DI), and free text communication (FTC) on top of driver advisory messages. This is a gamechanger for operational flexibility and real-time decision-making.
2. Digital Instructions (DI): streamlining operational lifecycle management
The new DI function aligns with Operation and Traffic Management Technical Specification for interoperability (TSI OPE) requirements, enabling seamless digital exchanging, tracking, and management of operational instructions. This ensures consistency, reduces errors, and enhances compliance across the rail ecosystem.
3. Free Text Communication (FTC): structured, traceable, and multilingual
Not safety critical but efficiency critical! FTC introduces structured, traceable, multilingual text communication between ground systems and train drivers. Whether a last-minute route change or a maintenance alert, FTC ensures clarity and precision in every message.
4. Use cases added for DI and FTC, better coverage for existing ones
Appendix A now includes DI and FTC use cases, offering a comprehensive set of examples, as well as a roadmap for implementing these functions. From emergency protocols to routine operations, the use cases ensure clarity and practicality for real-world applications.
5. Function-based separation in a unified Message Queuing Telemetry Transport (MQTT) infrastructure
The topic tree in Appendix B now has a function-based separation, allowing DAS, DI, and FTC to coexist on the same MQTT infrastructure while remaining logically distinct. This ensures improved understanding, scalability, security, and an efficient data flow without compromising integrity.
6. New payload families: DI and FTC in XSD 4.00
With SFERA XSD version 4.00, the protocol now supports dedicated message payload structures for DI and FTC. Appendices D and E detail the board-to-ground (B2G)/ground-to-board (G2B) Event/Request/Reply families, enabling seamless integration of these functions into existing and future systems.
7. XSLT Processor for European Instructions: Appendix I brings it to life
Say hello to a sample XSLT-based processor in Appendix I! This tool transforms SFERA Digital Instruction XML into human-readable, multilingual formats on board. Customisable layouts and reusable data models make it a practical, implementable example for operators worldwide.
8. Centralised reference hub: Appendix J for transparency and evolution
IRS 90940:2026 has a centralised repository in Appendix J, housing reference documents, NSP lists, implementation parameters, and protocol mappings. This public repository ensures the transparency, maintainability, and futureproofing of SFERA, decoupling evolving standards from the normative text.
Summary
The third edition of IRS 90940 is about redefining interoperability, efficiency, and safety in rail operations. By embracing SFERA’s expanded capabilities, the rail industry can unlock new levels of efficiency in automation, collaboration, and innovation.
Follow SFERA’s development:
Whether you are a developer, operator, or policymaker, the new edition of IRS 90940 offers a visionary framework for the future of train-ground communication.
Explore the full document, and join the movement toward a connected, intelligent rail network by staying tuned for more updates and discussions by registering for the User Group here: https://uic.org/events/irs-90940-sfera-change-requests-and-sfera-user-group.
Documents and support
Check latest SFERA workshop’s output for more familiarity with the features:
https://uic.org/events/uic-sfera-protocol-train-operation-data-exchange-workshop.
For access to the full IRS 90940 document, please visit the UIC Railway Publication website: https://shop.uic.org/en/909-digitalisation-data-emerging-innovations/15061-digitalisation-data-emerging-innovations-exchange-of-data-data-exchange-with-driver-advisory-systems-das-following-the-sfera-protocol.html.
For additional support, you can also reach out to Sfera at uic.org.
