Interoperability of railways rolling stock and infrastructure is essential for the further improvement of European rail transport operation. Harmonization of telecommunications in railway operation, with the goal of full interoperability, is a key element and a harmonized interoperable system in Europe is expected to open the way to global harmonization.

The European authorities have selected GSM-R as the radio transmission technology. This is defined in the technical specification for interoperability (TSI) relating to the control-command and signalling subsystems of the trans-European rail system, with standardization being a key to achieving a harmonized solution.

GSM-R is part of the ETSI/3GPP GSM specifications and applications have specific Quality of Service requirements for a harmonized railway operation. In addition, it operates in the ER-GSM band.

European railways

Within Europe, GSM-R is combined with the General Packet Radio Service (GPRS) to form the basis for an Intelligent Transport System that gives railways the means to improve the efficiency of rail operations and offer new services to users.

ERTMS, the European Rail Traffic Management System, is the rail management system which combines the European Train Control System (ETCS) with GSM-R. As a unique European train control system, ERTMS is designed to gradually replace the existing incompatible systems throughout Europe. This should bring considerable benefits to the railway sector as it allows seamless international freight and passenger transport. Moreover, ERTMS as train control system brings significant advantages in terms of maintenance costs savings, safety, reliability, punctuality and traffic capacity.

Beyond Europe

The GSM-R system continued to spread to even wider geographical areas. Beyond all European countries, it was adopted, among other places, in Saudi Arabia and Israel in the Middle East. In the Far East it has extended into India, China and Australia, where networks are implemented. This is also the case for South Africa as well as all North Africa countries. By the end of 2016, 56 countries in 5 continents selected GSM-R for their Rail operation.

Beyond GSM-R: the Future Rail Mobile Communication System (FRMCS)

UNITEL, the Rail Industry Group has indicated that support of GSM-R products and services are guaranteed at least until 2030. Based upon this information, the railway sector had to mitigate the risk of non-availability of GSM-R as radio system for train operation after this date.

Replacement of GSM-R equipment (on-board and trackside) by new equipment offering new services (which cannot be provided by GPRS) while maintaining interoperability has to be considered in a global timeline. For this reason, the evolution of the GSM-R is currently under discussion and the UIC (International Union of Railways), in cooperation with the European Union Agency for Railways, commenced discussions on the Future Rail Mobile Communication System (FRMCS) already in 2013.

In 2015, ETSI’s Technical Committee for Rail Telecommunications (TC RT), home of the GSM-R standard, started to work on the Next Generation Radio for Rail while 3GPP which develops the standards for mobile communications systems, has created a study item on Future Railway Mobile Communication System. Beyond the technology (or technologies) of choice, one of the main challenges in the future radio communication system for railway was the spectrum and a great achievement was reached with the adoption in EU of the COMMISSION IMPLEMENTING DECISION (EU) 2021/1730 of 28 September 2021 on the harmonised use of the paired frequency bands 874,4 to 880,0 MHz and 919,4 to 925,0 MHz and of the unpaired frequency band 1 900 to 1 910 MHz for Railway Mobile Radio.

Apart from the spectrum availability at European level which was achieved, the challenge is related to the required additional investment in 5G based FRMCS of potentially new radio sites rollout with respect to the installed base of GSM-R radio sites whose rollout in Europe is still ongoing.

Our Role & Activities

The standardization work is carried out by a dedicated ETSI Technical Committee (TC), Rail Telecommunications (RT).


ETSI's standardization activities for GSM-R within TC RT focuses on the application of GSMTM for railway telecommunications. This includes its improvement with additional features and services sought by the railways including the usage of GPRS/EGPRS for ETCS operation and IP-based protocols such as SIP. TC RT is the basis for proposal of revision needed to operate the rail system while ensuring complete interoperability.

Future Rail Mobile Communication System (FRMCS)

An essential step is now allocated to TC RT in studying the next generation end-to-end system architecture for rail transportation supporting multiple access technologies. TC RT continues to work closely with the International Union of Railways (UIC) proposed use cases and user requirements for FRMCS and is heavily involved in the standardization process for Mission Critical Communications within 3GPP for the normative specifications development related to FRMCS encompassing the user requirements. Ongoing challenges in this work include positioning aspects, train speed up to 500km/h and the integration of rail frequency spectra for the use of 3GPP radio technologies with a focus on 5G New Radio (NR). TC RT is also deeply involved in spectrum issues related to FRMCS and radio performance simulations in 900 MHz FDD and 1 900 MHz TDD spectrum for both LTE and 5G New Radio (NR) technology. FRMCS normative work in response to includes, among other things, the FRMCS System Architecture (TS 103 764) as well as FRMCS building blocks and functions (TS 103 765). A first set of FRMCS Technical Specifications is expected to be finalized by the end of 2022.

TC RT also works in cooperation with TC ITS for the investigation of the shared usage of 5GHz frequency band (5 875 to 5 925 MHz) for Urban Rail and ITS. This work takes place in a dedicated task force between TC RT and TC ITS (JTFIR).

ETSI TC RT is represented in JPC-Rail (Sector Forum Rail), RASCOP (Standardization Coordination Platform for Europe) as well as EUAR TWG STA (European Union Agency for Rail Topical Working Group on Standardisation) coordination groups.


A full list of related standards in the public domain is accessible via the RT committee page.