GSM-R
GSM-R is the 2G-based railway radio standard that provides the telecom bearer used for operational voice and, where deployed, ETCS data in ERTMS.
GSM-R is used on many European main lines as the dedicated train radio for drivers, dispatchers and shunting staff. It supports operational voice (including priority and group calls) and can also carry signalling-related data where used, with priority and availability managed by the railway network.
Technical description
GSM-R is based on GSM, with railway-specific functions such as functional addressing, group calls, broadcast calls and priority handling for operational and emergency communications. In Europe it typically uses the paired “R-GSM” spectrum around 900 MHz (uplink 876–880 MHz / downlink 921–925 MHz), separate from public mobile networks.
Role in ERTMS and ETCS
In ERTMS architecture, GSM-R is the radio bearer between onboard ETCS and trackside systems, notably the Radio Block Centre in ETCS Level 2 and Level 3.
On ETCS lines using radio, GSM-R becomes safety-relevant. If the data link is lost, trains revert to defined degraded modes under ETCS and national rules.
Coverage and radio planning
GSM-R coverage is engineered as a corridor network along the railway, including tunnels and cuttings. Base-station spacing is driven by geography, speed, required continuity and handover performance, with dedicated solutions in tunnels and complex terrain.
Because GSM-R sits adjacent to public mobile bands, coexistence and interference management can matter in dense mobile environments.
Deployment and use cases
Beyond ETCS data, GSM-R supports driver–dispatcher voice, shunting communications, station and yard operations, and emergency procedures. In many networks it replaced a patchwork of analogue and national radio systems to support interoperable operational communication, including cross-border services.
End-of-life and migration to FRMCS
GSM-R is nearing end-of-life because it relies on 2G and the supplier ecosystem is shrinking. The planned successor is FRMCS (Future Railway Mobile Communication System), designed to carry higher data volumes and support new digital railway applications.
Migration is not just a radio swap. It affects onboard equipment, trackside radio access, coverage assurance, operating rules and the transition strategy on ETCS lines that depend on GSM-R as a data bearer.
History
EIRENE/MORANE work converged in the late 1990s; GSM-R specs stabilised around 2000, after which deployment scaled with ERTMS rollouts. Current programmes focus on managing end-of-life risk while preparing parallel introduction and migration to FRMCS.