Future Railway Mobile Communication System (FRMCS)
The Future Railway Mobile Communication System (FRMCS) is the planned digital communication standard for European railways. It is designed to replace the existing GSM-R (Global System for Mobile Communications – Railway) network and provide the backbone for future digital railway operations. FRMCS is based on 5G technology and will support both operational safety systems and new passenger services.
Background
Development of FRMCS began under the coordination of the European Union Agency for Railways (ERA) as part of the European Rail Traffic Management System (ERTMS) programme. GSM-R, introduced in the early 2000s, no longer meets the capacity requirements of modern digital railway applications. To ensure cross-border interoperability, FRMCS is being standardized at EU level.
The system will use spectrum at 1900 MHz allocated specifically for railways by the European Conference of Postal and Telecommunications Administrations (CEPT). This dedicated band is intended to avoid interference and guarantee secure and reliable communication along railway corridors.
Characteristics
FRMCS builds on 5G New Radio but with adaptations for mission-critical rail operations. It supports secure voice communication between drivers and traffic control, data exchange for automatic train protection, and real-time operational monitoring.
Key features include low latency for safety-critical functions, network slicing to prioritize operational traffic, and reliable handover at train speeds up to 500 km/h. The system is designed to coexist with GSM-R during the transition period, ensuring backward compatibility.
Unlike consumer mobile networks, FRMCS coverage must follow linear railway tracks rather than broad geographic areas, requiring specialized deployment strategies.
Implementation
Pilot projects and field tests are ongoing across several European countries. Initial deployments have demonstrated the system’s capacity to handle live railway operations, moving beyond laboratory testing. Tests also focus on cross-border interoperability, which is essential for international services on the Trans-European Transport Network (TEN-T).
Full replacement of GSM-R is foreseen between 2030 and 2035, depending on national timelines. The transition involves infrastructure managers, operators, and telecom providers working together to ensure continuity of service.
European integration
FRMCS is a central component of the EU’s railway digitalization strategy. It underpins initiatives such as Digital Automatic Coupling and advanced train control systems, which are expected to increase capacity and efficiency.
By providing a harmonized digital communication layer, FRMCS addresses the historic fragmentation of national systems and supports the EU’s Green Deal objectives by enabling a modal shift towards rail.
Deployment is coordinated through ERA to ensure technical compatibility across member states, with gradual rollout expected to continue through the 2030s.