Dear reader,

For more than two decades, GSM-R has been the invisible backbone of European railway operations. Embedded in signalling, voice dispatch, and train control, the 2G-based standard enabled the interoperable rail network that underpins ERTMS. Yet its technological foundations are now ageing faster than many stakeholders anticipated. Several manufacturers have indicated they plan to discontinue GSM-R equipment maintenance from around 2030, compressing the effective transition window to less than a decade — and in some corridors, considerably less.

The Future Railway Mobile Communication System (FRMCS) is not simply an upgrade. Built on 5G standards developed by 3GPP, it is designed to become the communications layer for a fundamentally different kind of railway: one where automated train operation (ATO), advanced traffic management, real-time telemetry, and high-definition video surveillance all share the same network. Where GSM-R provided a dedicated channel for voice and limited data, FRMCS is engineered to carry mission-critical applications with the bandwidth, latency, and reliability that the next generation of rail operations demands.

This ambition comes with substantial coordination challenges. FRMCS must be interoperable across borders, backward-compatible during the migration phase, and resilient enough to serve as safety-critical infrastructure. The specification work — led by the UIC in close coordination with ERA and ETSI — is still ongoing, with a second version of the Technical Specifications for Interoperability (TSI) expected in 2027. The research projects currently active across Europe are therefore not peripheral to the deployment timeline: they are the mechanism by which specifications are stress-tested, gaps are identified, and market-ready solutions are prepared.

Two projects in particular illustrate the breadth of what is still to be resolved. FP2-MORANE-2, launched in December 2024 under Europe's Rail and the SNS Joint Undertaking, will conduct end-to-end testing of FRMCS systems across multiple European rail networks through September 2027. 5G-RACOM, a Franco-German bilateral initiative that concluded in late 2025, addressed the migration layer directly — demonstrating how hybrid networks can allow FRMCS and GSM-R to coexist in the same frequency band during the transition, without requiring immediate infrastructure replacement.

Together, these initiatives reflect a pragmatic recognition: the railway sector cannot wait for perfect specifications before beginning deployment. It must learn by testing, adapt by demonstrating, and coordinate across national boundaries that have historically produced divergent procurement cycles. The window between now and 2030 is short, the investment requirements are substantial, and the consequences of an incomplete migration — stranded assets, fragmented interoperability, safety risks — are significant.

For railway operators, infrastructure managers, and suppliers, FRMCS is already a strategic planning imperative. What follows in this issue is a closer look at two of the most relevant ongoing research initiatives shaping how that transition will unfold.

The FRMCS transition is not a distant future scenario — it is a planning reality for procurement, network investment, and operational strategy across the European rail sector today. The projects featured in this edition represent the leading edge of that transition, from high-level specification validation to concrete field demonstration of hybrid migration architectures.

Best regards,

Your RMR-Team