Skip to content
Independent reference on the Future Railway Mobile Communication System
FRMCS ATLAS

Knowledge · reviewed 02 Oct 2026

GSM-R to FRMCS migration

Contents
  1. Planning dimensions
  2. Interoperability
  3. What we do not state

Short answer

Migration from GSM-R to FRMCS is expected to include a period of coexistence in which both systems operate in parallel. Planning typically covers onboard fleet equipment, trackside infrastructure, spectrum, operational procedures and cross-border interoperability.

Planning dimensions

  1. Coexistence – how long both systems run in parallel and how services are handed over.
  2. Onboard – retrofit or new-build equipment across mixed fleets.
  3. Trackside – radio sites, core network and backhaul.
  4. Spectrum – frequency availability under national and European rules [3].
  5. Operations – procedures, training and incident handling.

Interoperability

For cross-border operation in Europe, the interoperability framework (TSI) defines mandatory requirements; check ERA for the version in force [3].

What we do not state

This page does not give country-specific timelines. Where such dates appear on the Standards page, they are labelled as planned or confirmed and linked to the original source.

Cite this page

GSM-R to FRMCS migration. FRMCS Atlas. /knowledge/gsm-r-to-frmcs-migration (last reviewed 2026-10-02). Markdown version

Related

Sources

  1. [1]FU-7100 – FRMCS User Requirements Specification — UIC, 5.0.0 (19 Feb 2020)
  2. [2]ETSI TS 103 764 — System Architecture — ETSI TC RT, v1.1.1
  3. [3]CCS TSI Appendix A – mandatory specifications (ETCS B4 R1, GSM-R B1 MR1, FRMCS B0) — ERA