GSM-R
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 something "5G"-based (specifically 3GPP R15/16), 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: 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 both being used around the world. Europe. Europe includes the CEPT member states, which include all EU members and Albania, Andorra, Azerbaijan, Belarus, Bosnia Herzegovina, Georgia, Iceland, Liechtenstein, North Macedonia, Moldavia, Monaco, Montenegro, Norway, Russia, San Marino, Serbia, Switzerland, Turkey, Ukraine, the United Kingdom, and Vatican City. GSM-R uses a specific frequency band, which can be referred to as the "standard" GSM-R band: 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 the full usage of the new frequencies is aimed for 2015. China. GSM-R occupies a 4 MHz wide range of the E-GSM band (900 MHz-GSM). India. GSM-R occupies a 1.6 MHz wide range of the P-GSM band (900 MHz-GSM) held by Indian Railways: Australia. GSM-R is being implemented within DCS 1800 band 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: 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. Current Interim versions are FRS 7.1 and SRS 15.1. The GSM-R specifications are fairly stable; the latest mandatory upgrade was in 2006 . The complete timeline of GSM-R versions is: 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 : Main use. 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. In addition, trackside signals become redundant. Other uses . 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: There are other additional features: 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. 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. GSM-R Numbering Plan. The EIRENE SRS document defines a fixed numbering plan for GSM-R. It is defined by number prefixes. Those numbers are used for functional registration and fixed entries for MSISDN or short dialcodes as defined within the HLR. 807660 for example defines a MSISDN of a mobile subscriber. The number 23030301 would be a functional number associated with the train number  30303 and the role of the user 01. GSM-R market. GSM-R market groups. Different groups make up the GSM-R market: Railways using GSM-R. Australia. Transport NSW is installing a Digital Train Radio System (DTRS) throughout the electrified rail network, including 66 tunnels covering , bounded by Kiama, Macarthur, Lithgow, Bondi Junction and Newcastle with GSM-R to replace the existing analogue MetroNet train radio. The replacement will fulfil recommendations from the Special Commission of Inquiry into the Waterfall rail accident to provide a common platform of communication for staff working on the railway. The equipment will be  installed at about 250 locations and more than 60 sites in tunnels. The old analogue network was dismantled in 2020. Public Transport Victoria has installed a Digital Train Radio System (DTRS) on the Melbourne train network with GSM-R to replace the old system called Urban Train Radio System (UTRS). The equipment was installed at about 100 locations. It cost $152 million. France. In France, the first commercial railway route opened with full GSM-R coverage is the LGV Est européenne linking Paris Gare de l'Est to Strasbourg. It was opened on 10 June 2007. Italy. As of 2008 , in Italy more than of railway lines are served by the GSM-R infrastructure: this number includes both ordinary and high speed lines, as well as more than of tunnels. Roaming agreements with other Italian mobile operators allow coverage of lines not directly served by GSM-R. Roaming agreements have also been set up with French and Swiss railway companies and it is planned to extend them to other countries. Netherlands. In the Netherlands, there is coverage on all the lines and the old system called Telerail was abandoned in favour of GSM-R in 2006. Norway. In Norway, the  GSM-R network was opened on all lines on 1 January 2007, replacing the older Scanet network. UK Mainland. The implementation of over of GSM-R enabled railway, intended to replace both its legacy VHF 205 MHz National Radio Network (NRN) and UHF 450 MHz suburban Cab Secure Radio (CSR) systems is now complete as of January 2016. , the only areas of UK Network Rail still currently employing VHF train radio communications are on sections of the Highland and Far North lines in Scotland, where the Radio Electronic Token Block system is utilised, using modified Ofcom frequencies around 180 MHz , having been de-scoped from the National GSM-R plan, due to practical difficulties involved in deploying the GSM-R system in this region.