Equipping rail operators for a confident transition from GSM‑R to FRMCS 

The upcoming Future Railway Mobile Communications System (FRMCS) will fundamentally reshape rail communications by replacing the ageing, voice-centric GSM-R with a modern, 5G-based digital platform.  

Approximately 80% of railways have already begun their transition to FRMCS, either through pilot schemes, planning or identifying suitable timelines. Once the industry has fully transitioned, operators expect to see more efficient operations, higher capacity utilisation, enhanced safety features, and a clear growth of revenue. In order to transition effectively and seamlessly, however, they will need support from experienced solutions providers like HUBER+SUHNER.

Operators are already preparing for FRMCS by upgrading their fiber backbones, deploying multi-band antennas, and trialling 5G-based mission-critical services, all while modernising passive infrastructure to handle higher data volumes and lower latency requirements. 

However, 91% of railways are still reliant on GSM-R today, and the technology remains deployed on over 140,000 km of track across Europe, meaning nearly the entire sector will have to transition before support ends for the technology in 2035. Compounding this issue is the fact that several countries are still rolling out GSM-R.  

If these nations are to keep up with the demands of modern rail, then they will have to rely on transitional solutions that enable the coexistence of both GSM-R and FRMCS operations until full migration to the latter becomes feasible.

HUBER+SUHNER believes the building of FRMCS-ready infrastructure starts with strengthening the foundational elements of rail networks, such as fiber, RF components, and connectivity systems that will have to carry far higher data volumes than GSM-R is currently capable of.  

Because FRMCS is a 5G based system, operators will require cutting-edge, fiber-dense backbones and cabling, alongside ruggedised components that enable higher frequencies and mission-critical reliability. This includes modular, future-proof architectures that allow rail operators to scale capacity, integrate new applications, and maintain reliable performance even as demands grow.  

However, one element that can accommodate the technology both during and after the full transition will be especially crucial to the enablement of FRMCS – antennas.

The expertise in rail solutions from HUBER+SUHNER has led to the introduction of a portfolio of SENCITY® SC Panel trackside antennas in 2025, designed to bridge the long coexistence period between GSM‑R and FRMCS. The range includes both GSM‑R‑only antennas (900 MHz) for countries still rolling out legacy systems and dual‑band GSM‑R/FRMCS antennas (900 MHz and 1900 MHz) that allow operators to deploy GSM‑R today while remaining fully prepared for FRMCS without having to replace any hardware.  

Crucially, these dual‑band models maintain the same physical geometry and wind‑load characteristics as the GSM‑R‑only versions, enabling operators to upgrade sites even where mast loading constraints prevent additional antennas.  

In March, we also launched an FRMCS-only SENCITY® SC Panel antenna to support customers once the full rollout begins in 2028. While FRMCS remains in the testing phase, we have launched a 2-port and 4-port version of this antenna, which should meet the growing expectations from the market regarding next-generation private networks. 

This antenna features an integrated RET with a frequency range of 1710-2170 MHz, and offers dual polarisation and a half-power beam width of 33°. Through this solution, operators will gain 20 dBi for their rail networks.

The transition to FRMCS is one of the most significant technological shifts the railway industry has faced in decades. As operators prepare for the migration from GSM-R to next-generation rail communications, they need a trusted partner capable of delivering a complete, future-ready connectivity solution, rather than just individual components. 

Building on decades of expertise in railway communications, HUBER+SUHNER provides a comprehensive portfolio for FRMCS deployments, covering antennas, RF distribution, fibre-optic connectivity, power cabling, protection solutions, mast-mounted units and mechanical infrastructure. Together, these technologies form an integrated ecosystem that supports reliable, high-performance trackside communications while enabling a smooth transition during the GSM-R and FRMCS coexistence period. 

This end-to-end approach is already being demonstrated in the ongoing MORANE 2 project, where we are working alongside Kontron Transportation and ADIF to support one of Europe's most important FRMCS initiatives. For the project, HUBER+SUHNER supplied the complete trackside connectivity backbone that connects trackside radios to the network and provides the power, fiber and RF infrastructure required for next-generation railway communications. 

By combining proven products with system-level expertise, HUBER+SUHNER helps railway operators simplify deployment, increase network reliability and create a practical path towards full FRMCS implementation.