GSM-R, Global System for Mobile Communications – Railway or GSM-Railway is an international Wireless communications standard for railway communication and applications.
A sub-system of European Rail Traffic Management System (ERTMS), it is used for communication between train and railway regulation control centers. The system is based on GSM and EIRENE – MORANE specifications which guarantee performance at speeds up to 500 km/h (310 mph), without any communication loss.
GSM-R could be supplanted by LTE-R, with the first production implementation being in South Korea. However, LTE is generally considered to be a 4G protocol, and the UIC's Future Railway Mobile Communication System (FRMCS) program is considering moving to a 5G-based standard (specifically 3GPP R15/16, i.e. 5G NR), thus skipping two technological generations.
History GSM-R is built on GSM technology, and benefits from the economies of scale of its GSM technology heritage, aiming at being a cost efficient digital replacement for existing incompatible in-track cable and analogue railway radio networks. Over 35 different such systems are reported to exist in Europe alone.
The standard is the result of over ten years of collaboration between the various European railway companies, with the goal of achieving interoperability using a single communication platform. GSM-R is part of the European Rail Traffic Management System (ERTMS) standard and carries the signaling information directly to the train driver, enabling higher train speeds and traffic density with a high level of safety.
The specifications were finalized in 2000, based on the European Union-funded MORANE (Mobile Radio for Railways Networks in Europe) project. The specification is being maintained by the International Union of Railways project ERTMS. GSM-R has been selected by 38 countries across the world, including all member states of the European Union and countries in Asia, Eurasia and northern Africa.
GSM-R is a secure platform for voice and data communication between railway operational staff, including drivers, dispatchers, shunting team members, train engineers, and station controllers. It delivers features such as group calls (VGCS), voice broadcast (VBS), location-based connections, and call pre-emption in case of an emergency. This supports applications such as cargo tracking, video surveillance in trains and at stations, and passenger information services.
GSM-R is typically implemented using dedicated base station masts close to the railway, with tunnel coverage effected using directional antennae or 'leaky' feeder transmission. The distance between the base stations is . This creates a high degree of redundancy and higher availability and reliability. In Germany, Italy and France the GSM-R network has between 3,000 and 4,000 base stations. In areas where the European Train Control System (ETCS) Level 2 or 3 is used, the train maintains a circuit switched digital modem connection to the train control center at all times. This modem operates with higher priority than normal users (eMLPP). If the modem connection is lost, the train will automatically stop.
Upper system GSM-R is one part of ERTMS (European Rail Traffic Management System) which is composed of: ETCS (European Train Control System) GSM-R ETML (European Traffic Management Layer) EOR (European Operating Rules)
Frequency band GSM-R is standardized to be implemented in either the E-GSM (900 MHz-GSM) or DCS 1800 (1,800 MHz-GSM) frequency band which are used worldwide.
Europe Europe includes the CEPT member states, which include all EU members as well as Albania, Andorra, Azerbaijan, Bosnia Herzegovina, Georgia, Iceland, Liechtenstein, North Macedonia, Moldova, Monaco, Montenegro, Norway, San Marino, Serbia, Switzerland, Turkey, Ukraine, the United Kingdom, and Vatican City.
Although previously members of the CEPT, in 2022, Russia and Belarus had their memberships indefinitely suspended in the wake of the Russian invasion of Ukraine.
GSM-R uses a specific frequency band, which can be referred to as the "standard" GSM-R band: Uplink: 876–880 MHz used for data transmission Downlink: 921–925 MHz used for data reception
In Germany, this band was extended with additional channels in the 873–876 MHz and 918–921 MHz range. Being used formerly for regional trunked radio systems, full use of the new frequencies was planned for 2015.Meldung DB darf zusätzliche GSM-R-Frequenzen für Bahnfunk nutzen. In: DB Welt, Heft 12/2009, S. 15
China GSM-R occupies a 4 MHz wide range of the E-GSM band (900 MHz-GSM). Uplink: 885–889 MHz Downlink: 930–934 MHz
India GSM-R occupies a 1.6 MHz wide range of the P-GSM band (900 MHz-GSM) held by Indian Railways: Uplink: 907.8–909.4 MHz Downlink: 952.8–954.4 MHz
Australia GSM-R is being implemented within DCS 1800 band Uplink: 1,770–1,785 MHz Downlink: 1,865–1,880 MHz
DCS 1800 band was initially divided and auctioned in paired parcels each of 2 × 2.5 MHz with duplex spacing of 95 MHz. State rail operators acquired six mostly non-grouped parcels which cover 2 × 15 MHz of spectrum to deploy GSM-R.
State rail operators re-licensed 2 x 10 MHz of 1800 MHz spectrum in Adelaide, Brisbane, Melbourne, Perth, and Sydney for Rail Safety and Control Communications. All except for South Australian Department of Planning Transport and Infrastructure (Adelaide) re-licensed 2 x 5 MHz of 1800 MHz spectrum at commercial rates set by Australian Government.
Technical frequency usage in GSM-R The used modulation is GMSK modulation (Gaussian Minimum-Shift Keying). GSM-R is a TDMA ("Time-Division Multiple Access") system. Data transmission is made of periodical TDMA frames (with a period of 4.615 ms), for each carrier frequency (physical channel). Each TDMA frame is divided in 8 time slots, named logical channels (577 μs long, each time-slot), carrying 148 bits of information.
There are worries that LTE mobile communication will disturb GSM-R, since it has been given a frequency band rather close to GSM-R. This could cause ETCS disturbances, random emergency braking because of lost communications etc.
As a result, there is an increasing trend towards monitoring and managing GSM-R interference using active and automated testing on board trains and trackside.
Current GSM-R version The GSM-R standard specification is divided in two EIRENE specifications: Functional Requirement Specification (FRS): the definition of higher lever functional requirements System Requirement Specification (SRS): the definition of the technical solutions supporting the functional requirements
EIRENE defines the "Technical Specification for Interoperability" (TSI) as the set of mandatory specifications to be fulfilled to keep compatibility with other European networks; current TSI are FRS 7 and SRS 15. EIRENE also defines non-mandatory specifications, that are called "Interim version", which defines extra features that are likely to become mandatory in the next TSIs. The current versions are 21 December 2015 versions FRS 8.0.0 and SRS 16.0.0 The GSM-R specifications are fairly stable; the latest mandatory upgrade was in 2006. The complete timeline of GSM-R versions is: December 2000: FRS 5/SRS 13, first version to be widely installed October 2003: FRS 6/SRS 14 May 2006: FRS 7/SRS 15, current TSI June 2010: FRS7.1/SRS 15.1, current Interim version; the main added features over TSI are shunting radio and ETCS data only radio
The current version of GSM-R can run on both R99 and R4 3GPP networks.
GSM-R uses GSM-R permits new services and applications for mobile communications in several domains: Transmission of Long Line Public Address (LLPA) announcements to remote stations down the line Control and protection (Automatic Train Control/ETCS) and ERTMS Communication between train driver and regulation center Communication of on-board working people Information sending for ETCS Communication between train stations, classification yard and rail tracks
It is used to transmit data between trains and railway regulation centers with level 2 and 3 of ETCS. When the train passes over a Eurobalise, it transmits its new position and its speed, then it receives back agreement (or disagreement) to enter the next track and its new maximum speed.
Like other GSM devices, GSM-R equipment can transmit data and voice. New GSM-R features for mobile communication are based on GSM, and are specified by EIRENE project. Call features are: PtP Call: Point-to-Point Call, the same type of call as a normal GSM call VGCS: Voice Group Call System, quite similar to walkie-talkie communication but with a single uplink handled by the network (only one person can speak at a time) VBS: Voice Broadcast System, like a VGCS but only the call initiator can speak (the other are only listeners) REC: Railways Emergency Call, is a special VGCS defined as 299 with the highest priority possible (0) SEC: Shunting Emergency Call, is a special VGCS defined as 599 with the highest priority possible (0) Priority control of all the different calls (PtP, VGCS, VBSm, REC and SEC calls) There are other additional features: Functional Addressing, alias system to call someone registered on the GSM-R network, only by knowing the temporary function user (engine driver of train such-and-such, ...) Location Dependent Addressing, routing system to call the most appropriate train controller regarding the current train position by dialling a pre-defined short code Shunting mode, when users work on the tracks.
GSM-R features
ASCI (Advanced Speech Call Items) features The following definitions are a part of the System Requirements Specification (SRS) as defined by the EIRENE standard.
VGCS (Voice Group Call Service) VGCS allows a great number of users to participate in the same call. This feature imitates the analogue PMR (Private Mobile Radio) group call with the PTT key (Push-to-Talk).
Three kinds of users are defined: the Talker, the Listener and the Dispatcher. The talker can become a listener by releasing the PTT key and a listener becomes a talker by pressing the PTT key.
One advantage of VGCS compared to multi-party calls (the GSM conference call feature) is the spectrum efficiency. Indeed, when many users are in the same cell they will use only one frequency for all listeners and two frequencies for the talker (as in point-to-point call). In a multi-party call, one timeslot is dedicated to each user. The second advantage compared to multi-party calls is that it is not necessary to know which mobiles are to take part in the call. A VGCS call is established on a purely geographic basis, subject to a mobile having previously enabled reception of the group concerned.
VBS (Voice Broadcast Service) VBS is a broadcast group call: this means that compared to VGCS, only the initiator of the call can speak. The others who join the call can only be listeners. This kind of call is mainly used to broadcast recorded messages or to make announcements.
REC (Railway Emergency Call) REC is a group call, or VGCS, dedicated to urgency. It is a higher priority call (REC priority is level 0 – see below : eMLPP).
SEC (Shunting Emergency Call) The Shunting Emergency Call is a dedicated group call with the number 599. The call is established with an emergency level priority whose level is the highest possible priority 0. The SEC is enabled and used by devices registered for shunting operations. The establishment of such a call leads to automatic acceptance of the call on all enabled devices within the current area or cell-group configured.
Multi-Level Precedence and Pre-emption Service (eMLPP) This defines the user's priority. The different priority levels are:
A and B: Highest priority levels (not used by GSM-R networks) 0: Highest priority levels for ASCI and normal calls (mainly used for REC calls) 1: Lower priority than level 0 2: Lower priority than level 1