SIST EN IEC 61375-1:2026

Overview

SIST EN IEC 61375-1:2026 specifies the general architecture of Train Communication Networks (TCN) for electronic railway equipment, focusing on open trains but also applicable to closed and multiple unit trains by agreement. The standard outlines fundamental aspects regarding the data communication systems connecting railway vehicles, within vehicles, and between trains and ground infrastructure. This fourth edition introduces several technical updates, enhancing interoperability, cybersecurity, and the adoption of modern communication technologies like wireless and virtual networks.

The standard is developed by the Slovenski inštitut za standardizacijo (SIST) and aligns with International Electrotechnical Commission (IEC) guidelines, ensuring global relevance. By defining the TCN architecture, the standard enables seamless communication and system integration across international and mixed vehicle fleets, contributing to safe, reliable, and efficient railway operations.

Key Topics

Main Elements Covered:

• TCN Hierarchical Structure: Defines two core levels - the train backbone (interconnecting vehicles) and consist networks (within individual consists).
• Network Topologies: Extension to include aggregated and segregated backbone topologies, supporting greater flexibility in train compositions.
• Wireless Technologies: Introduction of wireless train backbone and wireless consist networks, reflecting technological advancements.
• Virtual Networks: Guidelines for the implementation and operation of virtual networking solutions within train communication systems.
• Interoperability: Framework for compatibility and proof between train backbones and consist networks, critical for international and multi-vendor interoperability.
• Data Classes & Protocols: Definitions tailored for onboard multimedia and telematics services (OMTS) as well as operational data handling.
• Cybersecurity: A dedicated new clause addressing threat prevention, detection, system integrity, network segmentation, authentication, authorization, and protection of data in transit.

Technical Changes from Previous Edition:

• Aggregated and segregated train backbone topologies
• Independent consist orientation check for segregated backbone
• Wireless communication support for backbone and consist networks
• Introduction of virtual networks
• Data class and protocol requirements for OMTS
• Comprehensive guidelines for cybersecurity in TCNs

Applications

Practical Uses of SIST EN IEC 61375-1:2026:

• Railway Fleet Modernization: Supports the integration of new vehicles into existing fleets, regardless of manufacturer, by guaranteeing interoperable network communication.
• International Operations: Facilitates seamless operation of railway vehicles across country borders and between various operators by adhering to a common communication architecture.
• System Upgrades: Lays out the requirements and recommendations for upgrading legacy networks and deploying new wired or wireless communication solutions in trains.
• Cybersecurity Management: Assists operators and suppliers in implementing robust cybersecurity measures to safeguard critical train communication networks from cyber threats.
• Operational Efficiency: Enables implementation of reliable, scalable, and adaptive communication systems, improving maintenance, diagnostic, and operational workflows.

Related Standards

• IEC 61375 Series: Comprehensive set of standards detailing specific technologies and protocols for train communication networks.
• EN TS 50701: Technical specification focusing on cybersecurity applicable to railway applications.
• IEC 62443-4-2: Addresses security for industrial automation and control systems, referenced for essential function and cybersecurity definitions.
• IEEE 802.1Q: Specifies standards for local and metropolitan area networks, including VLANs relevant to the networking part of TCNs.

Railway operators, system integrators, and suppliers are encouraged to reference these and related documents when designing, implementing, or assessing train communication networks in accordance with SIST EN IEC 61375-1:2026.