Standards Development

Scope

This International Standard shall provide the definition of a safe data transmission protocol in accordance with IEC 62280.

This International Standard shall be applicable for safety-related electrical, electronic and programmable electronic systems (E/E/PES including sub-systems and components) for railway signal applications. This document does not apply to safety protocols inside on-board train communication networks.

This International Standard is not in contradiction to the horizontal standards on OT-Security / Cybersecurity.

This International Standard provides definitions and recommendations for Rail Safe Transport Application (RaSTA), a safe data transmission protocol for railway communication given by the German national standard VDE V 0831-200. The layered protocol architecture is defined together with the protocol data units for every layer. The dynamic behavior is defined using state transitions and sequences. Additionally, functional descriptions are used to define the main procedures for handling telegrams at reception and sending. To enhance availability, RaSTA is defined for use of several transport channels and retransmission of telegrams.

This International Standard does not support a specific implementation but provides enough details to ensure compatible interfaces between different implementations of RaSTA.

The detailed specification of interfaces related to the application and to the underlying transport layer are not in the scope of this International Standard. Transport layers are not specified by this International Standard, but well-defined transport layers may be used.

The attached documents show the current outline of the proposal after discussion and alignment in IEC TC9 AHG28.

Purpose

Due to ongoing modernization in rail infrastructure, the efficient coupling of systems from different suppliers is required. For this purpose, communication interfaces based on standard network communication are needed. From the operators’ point of view, it is essential to have a commonly accepted set of definitions and recommendations for safe data transmission protocols to define such interfaces within railway signaling systems over several protocol layers. This international standard shall supply and ease interface specifications in safety relevant railway signaling applications between different suppliers by giving a set of possible safety protocols. This proposal supports the safety target for electronic signaling systems and is not in contradiction to IEC 62278.

The need to establish an International Standard for safe transmission protocols according to IEC 62280 is also identified by EULYNX, the consortium of 17 European Railway Infrastructure Managers defining interface requirements from operators’ perspective. EULYNX member companies are part of the NCs.

Therefore, this NP is written and addressed to IEC TC9. The technical requirements are not limited to European applications and European Legal Framework. Thus, according to the Frankfurt Agreement, the proposer sees no justification to address this proposal to CENELEC only. A safe transmission protocol is applicable world-wide, the requirements can be adopted for specific application conditions. The relationship to IEC 62280 is not in contradiction to activities on IEC TC9 or on CENELEC TC9X level.

After establishment of IEC TC9 AHG28 the involved experts of 12 countries identified the need to structure the documents in four parts for better understanding. Therefore, the NPs are based on the following structure:

Part 1: Generic aspects of safety related transmission protocols

Part 2: RBC-RBC Safe Communication Interface

Part 3: PVS: Safety related transmission protocol for application between ground systems

Part 4: Rail Safe Transport Application Protocol

IEC TC 9 AHG28 recommends publishing these documents with the same IEC number (e.g., 6xxxx-1/-2/-3/-4)

The proposer and convenor of IEC TC 9 AHG28 gave a presentation on this NP at the 65th plenary IEC TC9 meeting within the report IEC TC9 AHG28. The NPs were distributed as document 9(NDelhi/Secretariat)06.