GSM-R

GSM-R is an international standard of mobile communication for the railroads.

Technology GSM-R

Definition

GSM-R ( Mobile Global System for communications - Railways ) is a standard of communication without wire based on GSM, and specifically developed for the railway applications and communications.

It allows the trains communicating with the stations of regulation of the rail traffic, the supervisors, of circulation and maintenance to communicate between them in mode conference (calls of group), and it authorizes the support of applications of the type given such as for example ETCS.

The standards EIRENE - MORANE specify a functional use and without cut of communication in GSM-R until a rate of travel of the train of 500 km/h.

History

Standard GSM-R was developed within the framework of the mission that was given the International union of the railroads (UIC). Its initial goal was the standardization and the improvement of the conditions of construction and operating of the Railroads, particularly as regards international traffic. In order to develop this standard the project EIRENE was set up in 1993 by UIC. It is within this project that the specifications to which network GSM-R must satisfy were developed.

The GSM-R, which is built starting from technology GSM, profits from the economies rising from this heritage. It authorizes a numerical change at a competitive cost, allowing the replacement of all the communication systems telegraphic (along the way) and of the radio operator networks railway analogical existing in each country which are incompatible between them: one enters indeed more than 35 different communication systems railway, only in Europe…

The GSM-R is a platform made safe for the communications of voice and data, between the various members of the railway teams: drivers, regulators, members of the team of operation, personnel on train, station masters. It brings devices such as the calls of groups (VGCS), the advertisements or calls diffused (VBS), the located calls, and the pre-emption of the calls in the event of urgency. It will be able to support applications such as the follow-up of the goods, the video surveillance in the trains and the Gare S, as well as the services of information of the users.

This standard which is the result of more than ten years of collaboration between the many railway companies Européennes, finalizes interworking by the use of a single platform of communication. The GSM-R allows in the cases of ETCS of level 2 and 3 (see ERTMS), to transport information of railway indication directly to the driver, thus facilitating a speed of higher circulation of the train as well as a denser traffic, while maintaining an high level of safety.

The specifications finalized in 2000, are based on European project MORANE (Mobile Radio for Railways Networks in Europe). The specifications are maintained by the project ERTMS of the International union of the railroads.

The GSM-R was chosen by 38 countries throughout the world, including all the Member States of the European Union, as well as countries of Asia, Eurasia and North Africa.

The GSM-R in general uses turns relay (Base Transceiver Station) dedicated, close to the railway. The distance between each BTS is of 3-4 km. This proximity creates an high degree of redundancy and a larger cover and reliability. The train maintenance permanently a numerical connection by Modem towards the center of regulation of the trains. This connection has a level of priority higher than the other users (eMLPP). If the connection of the modem is lost, the train stops automatically. In Germany, Italy and France, network GSM-R counts between 3000 and 4000 BTS.

Higher system

The GSM-R is a component of the ERTMS which includes/understands:

ETCS (European system of the control of the trains).
the GSM-R.

Waveband

In Europe, the GSM-R uses the following Waveband dedicated:

876 MHz - 880 MHz: for the emission of data (uplink)
921 MHz - 925 MHz: for the reception of data (downlink)

The frequency separation between each physical channel is of 200kHz.

The modulation is of type GMSK (Gaussian Minimum Keying Shift).

The GSM-R is also a system TDMA (" Time-division Multiple Access"), i.e. of temporal multiplexing where transmission of the data and organized for each Carrying (or physical channels) by periodic Screen TDMA (period of 4.615 ms).

Each Trame TDMA is cut out in 8 time intervals (" Time Slots") also called logical channels (one duration of 577 µs each one), composed of 148 Bit S of information.

The GSM-R uses a lower extension of the frequencies of the GSM 900 MHz (band 890 MHz - 915 MHz for the emission and bandages 935 MHz - 960 MHz for the reception). In China, the GSM-R uses a beach of 4 MHz of band E-GSM (GSM 900Mhz).

Applications

The GSM-R allows new services and applications; it offers in particular possibilities of mobile communication in the fields of:

the control and of protection (automatic Monitoring of the trains (Automatic Train Control ETCS) and ERTMS)
the communication enters the '' mechanic '' and the leader of service,
the communication for the personal of train, as well as the teams working on train
the sending of message of the train for the monitoring service of the train
the communication for the personnel on the Gare S, the sites of goods and on the ways
of the applications specific to each country, like the communication in the tunnels, it transfer and data analysis of service, the control datas…

First application

It is used to transmit the data between the trains and the stations as regulation of the rail traffic with levels 2 and 3 of the system ETCS. Thus when the train arrives on one of the Eurobalise S, it communicates its new position and its speed and receives in return the authorization to enter or not on the following canton and new maximum speed. There does not need thus more side indication.

Other applications

Just like the equipment of telephony GSM, equipment GSM-R makes it possible to transmit data and also of the voice. The new functionalities brought by the GSM-R in terms of mobile communication, are based on standards GSM, and are described by the standards of the Projet EIRENE. One finds in particular for the calls:

the call point-with-point ( PtP Cal : Point-to-Point Cal ), call identical to those of a normal GSM
the call of group ( VGCS : Voice Group Cal System ), kind of communication similar to the rotation in Radiotelefony
the call of diffusion ( VBS : Voice Broadcast System ), where there is only one person who can speak (the others listen only)
the emergency call ( REC : Railways Emergency Cal ), which is a kind of call of group dedicated to an urgency
a management of the various types calls (PtP, VGCS, VBS and REC) by priority

One also finds the functionalities following:

functional addressing ( Fonctional Adressing ), system of alias which makes it possible to record near network GSM-R the number of a telephone as a temporary function occupied by its user (conducting, controller of a particular train…)
an operating process specific to the operations ( Shunting ), i.e. work on the ways with the development where the storage of a railway convoy.

Functionalities GSM-R

Devices ASCI ( Advanced Speech Cal Items )

VGCS (Voice Group Cal Service)

the VGCS makes it possible a great number of users to take part in the same call. This device imitates the call of group PMR (Private Mobile Radio) analogical with button postal and telecommunications authorities ( Push-to-Talk ).

Three kind of users are defined: Talker ( That which speaks ), Listener ( That which listens to ) and the Dispatcher ( the Regulator ). The talker can become a listener by slackening button postal and telecommunications authorities and the listener becomes a talker' while pressing on button postal and telecommunications authorities.

the main advantage of the VGCS compared with a call multi-party (the device of call of conference of GSM) is the optimization of the occupation of the waveband. Thus, when many user are in same cell (GSM) they will use a frequency for all the listeners and two frequencies for the talker (as for a call point-with-point). At the time of a call multi-party there are two frequencies used for each user.

VBS (Voice Broadcast Service)

the VBS is a call of diffusion: with the difference of a VGCS, only the person having initiated this call can speak, the other participants in the call can only listen. This type of call is used mainly to diffuse messages preregistered or to make advertisements.

REC (Railway Emergency Cal: Emergency call train)

REC is call of group, or VGCS, dedicated to an urgency. It has a priority superior with that of other calls (a REC has a priority of level 0 - to see below: eMLPP)

Service eMLPP (Multi-Level Precedence and Pre-emption Service)

This service definite of the priorities for the calls of the users. One finds the level of priority according to:

*A and b: Level of priority most important (Reserved for the message of the network)

*0: The priority level among service ASCI (Mainly used for the emergency call train - REC)

*1: Level priority than the level 0

*2: Level priority than level 1

*3: Level priority than level 2

*4: The priority level (Priority by defect, it is allotted to the point-to-point calls)

a system of automatic answer ( Car-Answering ) time-lag is also available for the calls of priority 0,1 and 2.

Devices EIRENE ( European Integrated Railway Radio operator Enhanced Network )

Management of functional number ( Functional Number )

* Adressage by functional number

Makes it possible to call a mobile terminal ( ms or Mobile Station ) starting from its function: Driver of train xxx…

This function uses

the functions US and Follow Me

the function UUS1 (for the posting of the functional number)

* Adressage depend on the localization

Amélioration of the principle of addressing per functional number

Permet to call nearest ms attached to a function: nearer conducting, nearer controller,…

Confirmation of call

the system of confirmation of call is valid only for the calls of group (VGCS) and the calls of diffusion (VBS) of priority 0 (see eMLPP).

the principle consists for each mobile terminal having taken part in the call (initiating included/understood), to send a report/ratio when the call is left or finished. This report/ratio must contain like information:

* the type of call

* duration of the call

* identification of the mobile transmitting the

report/ratio * the cause of the end of the call (Normal, fine volunteer by the user, extinction of the voluntary mobile, extinction due to run down battery,…)

*…

If the report/ratio could not be sent (extinction of the voluntary mobile terminal or due to run down battery), the mobile terminal again tries to return it during its restarting.

Mode operates ( Shunting mode)

the " mode; Shunting" is the term used to describe the application which controls and controls the users who reach the communications shunting .

an aural signal, the " LAS" ( Link Insurance Signal ) is emitted with an aim of confirming to the mechanic (conducting train) that the radio operator bond is operational and functions.

Direct mode ( Direct mode)

the direct mode is the means of communication by rotation (walkie-talkie) where the mobile terminals communicate together without using the mobile network. He was proposed by the project Eirene, even if he forever applied since then.

SAGEM known as to have developed a direct mode GSM, currently not recognized in the specifications GSM-R, and for which no frequency is still allocated.

The market of the GSM-R

Constituent groups market GSM-R

The various groups which constitute the market of the GSM-R are: ; Managers of the infrastructure and operators railway

Source : UIC (5/23/2006)

; The suppliers of equipment of telecommunications

the companies Huawei, Nortel and Siemens are the leading vendors of the infrastructure of network GSM-R.

; Solutions for control center and of regulation:

Siemens Transportation Systems and Frequentis.

; The manufacturer of mobile terminals:

Manufacturer of telephones:

Sagem (SAFRAN group) is the leading vendor of telephone GSM-R, followed by, Triorail and Huawei.

Manufacturer of Cab-radio (Radio of Cabin Train):

Alstom, Siemens, Nortel and Hörmann is the leading vendors. and Sagem provides mainly heart GSM-R of these Cab-radios.

Actual position of deployment

In Germany, network GSM-R is in service since.

With the Netherlands, the GSM-R is the only means of communication: the use of the analogical radio ceased since the 1 {{er}} January 2007.

At the end of 2007 in France, the GSM-R is exploited commercially on the following lines:

Paris-Is with Châlons-in-Champagne (line Paris - Strasbourg) since January 28th, 2007.
Paris-Is with Gretz-Armainvilliers (line Paris - Mulhouse) since January 28th, 2007.
Esbly - Crécy since January 28th, 2007.
TTAB (Tram Train Aulnay Bondy) since November 18th, 2006.
EOLE (the RER E) of Magenta (Station of North) to Chelles-Gournay (line Paris - Strasbourg) and of Magenta with Gretz-Armainvilliers (Paris line - Mulhouse) while passing by Noisy-The-Dryness since January 28th, 2007.
LGVEE of Pomponne (junction of the line Paris - Strasbourg) to Herny since June 10th, 2007.

In 2007 in Great Britain the GSM-R is always with the test on the following lines:

in the county of the Strathclyde in Scotland,
on the West Coast Hand Line (WCML) between Rugby and Wembley.

For the moment, only mobile phones GSM-R are used to communicate. Network GSM-R Britannique should be fully operational only from here 2013, at a cost of £ 1,2 billion (This cost does not include/understand WCML).

Glossary GSM-R

ASCI : “ Advanced Speech Cal Items ”

Device of advanced calls voice, gathering the VGCS (normal and REC), VBS, and service eMLPP.

eMLPP : “ Multi-Level Precedence and Pre-emption Service ”

Service over management of priorities allotted to the calls voice.

GSM-R : “ Mobile Global System for - Railways ”

International standard of mobile communication for the railroads, based on the GSM.

PtP Cal: “ Point-to-Point Cal ”

point-to-point Call, i.e. a normal communication GSM between two interlocutors (call voice).

EIRENE : “ European Integrated Railway Radio Enhanced NEtwork ”

One distinguishes three entitées: the project EIRENE, standards EIRENE and device EIRENE.

the project EIRENE (project of Network Improved of Railway Radiocommunication Integrated European) is a project of dialog creates by UIC.
standards EIRENE.
device EIRENE gathers the functionalities of addressing per functional number, the system of confirmation of call (for the VGCS and VBS of priority 0), the mode operates and the direct mode.

US : “ Unstructured Supplementary Service Dated ”

Being able to result in Données Service Additional Little Structured , it is a functionality of short messages of telephones GSM. It is generally associated with the telephone services of the real-time type or instant messaging. The US is faster than SMS, but there is no possibility of recording and transfer.

VGCS : “ Voice Group Cal Service ”

Call of group (service ASCI).

VBS : “ Voice Broadcast Service ”

Call of diffusion (service ASCI).

REC : “ Railway Emergency Cal ”,

emergency Call train (specific VGCS of priority 0).

References

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