'GSM-R' (GSM-Railway) is an international communication standard for
railway communication and applications.
GSM-R technology
Definition
'GSM-R' (''Global System for Mobile communications - Railway'') is a sub-system of
ERTMS (European Rail Traffic Management System).
'GSM-R' is a
wireless communications platform developed specifically for
railway communication and applications.
It is mainly used to permit communication between train and railway regulation control centers. It is based on
GSM.
''EIRENE - MORANE'' specifications guarantee performance at speeds up to 500 km/h (310 mph), without any communication loss.
History
GSM-R transmitter mast at the Nuremberg–Ingolstadt high-speed railway line
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 new
European Rail Traffic Management System (ERTMS) standard and carries the signalling 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
EU-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 will support 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 towers close to the railway. The distance between the base stations is 3-4 km. This creates a high degree of redundancy and higher availability and reliability. The train maintains a
circuit switched digital
modem connection to the train control centre at all times. This modem operates with higher priority than normal users (eMLPP). If the modem connection is lost, the train will automatically stop. In
Germany,
Italy and
France the GSM-R network has between 3000 and 4000
base stations.
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.
Frequency band
In Europe, GSM-R uses a specific
frequency band[1]:
★ 876,2 MHz — 915 MHz: used for data transmission (uplink)
★ 921,2 MHz — 960 MHz: used for data reception (downlink)
Channel spacing is 200 kHz.
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.
GSM-R occupied a lower extension of GSM 900 MHz frequencies (890 MHz — 915 MHz range for transmission and 935 MHz — 960 MHz range for reception), as per 3GPP TS 05.05 V8.20.0 (2005-11). In
China GSM-R occupied a 4 MHz wide range of the E-GSM band (900 MHz-GSM).
GSM-R features
ASCI (Advanced Speech Call Items) features
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.
:The main 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 there are two frequencies by each user.
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 advertisements.
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)
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 (reserved to Network messages)
:
★ 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
:
★ 3: Lower priority than level 2
:
★ 4: Lowest priority level (default priority, assigned to Point-to-Point calls)
:An ''Auto-Answering'' feature with a timer is also available for calls with priority 0, 1 and 2.
Eirene features
Functional number management
:
★ Functional numbering
:
★
★ Allows to call an MS by its function: driver of the train xxx , …
:
★
★ It uses:
:
★
★
★ USSD and Follow Me
:
★
★
★ UUS1 (for number display)
:
★ Location dependent addressing
:
★
★ Improves the functional numbering
:
★
★ Allows to call the nearer MS linked to a function: nearer driver, nearer controller, …
End Call Confirmation
:End Call Confirmation feature is only available for highest priority (Priority level 0) group calls (VGCS) and broadcast calls (VBS) (see eMLPP).
:It consists of a end call report which is send by all MS (mobile station) which have joined the high priority call (Initiator include). This report inform about:
:
★ Call type
:
★ Call duration
:
★ MS Identity
:
★ End call cause Normal, ended by user, MS power off by user, power off due to low battery, …)
:
★ …
:If the report can't be sent (MS power off by user or power off due to low battery), the MS will try again (several times if needed) to send the report at the next power on.
Shunting mode
:Shunting mode is the term used to describe the application that will regulate and control user access to shunting communications.
:A Link Assurance Signal (LAS) is provided in order to give reassurance to the driver that the radio link is working.
Direct mode
:Direct mode is the walkie-talkie mode (mobiles station talking to each other without the network) and has been proposed in Eirene, however it has never been in application since being based on analogue radio.
:Sagem claims to have developed a GSM direct mode, not currently recognised in the GSM-R specification, and has no frequency allocation.
GSM-R market
GSM-R market groups
Different groups make up the GSM-R market:
;The network operators and the railway operators:
:
:
:
:
Source : UIC (23th of may 2006)[2]
;The network operators : The companies
Huawei,
Nortel and
Nokia Siemens Networks are the main suppliers of the GSM-R infrastructure.
;Dispatch and Control Centre Solutions:
Siemens Transportation Systems and
Frequentis
;The terminal manufacturers
:; Handset manufacturer
::
Sagem (
SAFRAN group) is the main GSM-R handset supplier, followed by
Selex,
Triorail and
Huawei.
:; Cab radio manufacturer
::
Alstom,
Siemens,
Nortel and
Hoermann are the main suppliers.
Funkwerk (formerly
Kapsch) and Sagem mainly provide the GSM-R core of these cab radios.
Railways using GSM-R
In Britain, in 2007 GSM-R is being trialled in the Strathclyde, Scotland while on the
West Coast Main Line (WCML) GSM-R is being used between Rugby and Wembley. At the moment though they are only using GSM-R enabled handsets to communicate. Britain’s GSM-R network should be fully operational by 2013 at a cost of £1.2 Billion. This cost though does not include the WCML.
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 the 10th of June 2007.
★ On Sunday,
June 10,
2007 at 0643, the first high speed train run on it was the
ICE, the
high speed train from the German passenger operator :
DB. It linked the ''
Gare de l'Est'' in
Paris to
Saarbrücken (
Germany).
★ On the same day, 0715, it was the opportunity of the
TGV POS, the last generation high speed train from the French operator,
SNCF. It linked
Strasbourg to Paris (Gare de l'Est).
''(Réf. SNCF - Paris AFP, 10th of june 2007)''
[3]
In Norway, the GSM-R network was opened on all lines on January 1st, 2007.
>
References
1. http://www.willtek.com/english/technologies/gsmr Willtek, radio measure devices provider
2. http://gsm-r.uic.asso.fr/implement_map.html UIC, GSM-R Implementation planning and progress map
3. Réf. SNCF - Paris Agence France Presse (AFP), Sunday the 10th of June 2007, 07h13 (am).
External links
★
UIC ERTMS/GSM-R Project
★
Siemens GSM-R
★
Nortel GSM-R
★
Frequentis Public Site
★
Sagem GSM-R
★
Triorail GSM-R
★
ERA ERTMS
★
Comtest Wireless
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