GSM-R, Advanced, Approved, Available and Applicable - Part…

AusRAIL Plus 2003 Sydney, 17-19 November 2003

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GSM-R – ADVANCED, AVAILABLE, APPROVED AND APPLICABLE

PART 2 – AVAILABLE AND APPROVED

JOHN AITKEN, AITKEN & PARTNERS MARTIN LEHRBAUM, NORTEL NETWORKS

GLYN OWEN, SIEMENS

SUMMARY GSM-R, the railway extension of GSM telephony, has been designed specifically to satisfy railway radio communication requirements. In this three-part paper, we describe the advanced features of GSM-R that set it apart as a railway system and demonstrate that it is available technology, ready for use today. We explain how GSM-R has been approved by international standards organisations and has a Notified Body process for type and system approval. Finally, we show that GSM-R is applicable to Australia, providing an effective solution to many of the communication problems of Australian railways. Part 2 discusses the approval processes for GSM-R, its implementation to date and the availability of GSM-R systems. INTRODUCTION “In the past the railways have tended to be guilty of failing to take opportunities to adopt common technical solutions, preferring, for traditional reasons, to procure on the basis of national railways' specifications. This procurement policy has led to the assumption that the railways technological needs are, for some reason, so special that commercial standards are inadequate to meet the needs of the operational railway. More importantly, it also led to supplier monopolies and solutions to user requirements that included performance demands but took no account of cost.”1 This could easily have been written about the state of train radio communications in Australia. It was in fact written about the situation in Europe, prior to the implementation of GSM-R. The GSM-R approach has completely changed that attitude. It has resulted in a genuine attempt to produce a solution that applies commercially based products without compromising safety or operational needs.

1 INTERNATIONALLY APPROVED 1.1 GSM Memorandum of Understanding In 1997, a large number of European railways agreed to develop a new train radio specification. In their Memorandum of Understanding, the signatories of this agreed that it was important that a common standard be introduced for train radio in Europe. The signatories to the Memorandum of Understanding agreed 2:

· To adopt those aspects of the ETSI GSM standard adopted for railway operations essential to interoperability as the basis for their new train radio systems.

· To implement the mandatory requirements of the EIRENE specification when it is, overall, economically advantageous on a particular route to do so to enable interoperability of rolling stock across international boundaries.

· To co-operate with neighbouring railways on the introduction of new systems to enable as rapid an introduction as possible.

· To co-ordinate with neighbouring railways or other radio spectrum licence holders,

John Aitken GSM-R, Advanced, Available, Approved and Applicable Martin Lehrbaum Glyn Owen Part 2 – Available and Approved


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where applicable, on the allocation of frequencies from CEPT recommendation TR 25-09.

· To exchange information on the practical experience gained in the implementation of systems.

1.2 Industry Based Organisations In order to meet the changing needs of the project as it moved from specification to implementation, the UIC European Railway Implementers Group (ERIG) was established at the beginning of 1999. ERIG has taken responsibility for overseeing the remaining elements of the project necessary to guarantee the interoperability of national GSM-R implementations. The Group is chaired by Klaus Konrad of the German railways, one of the first implementers of GSM-R, and comprises of representatives from Memorandum of Understanding signatory railways with an interest in implementing GSM-R networks. In addition to ERIG, the following working groups have been created: GSM-R Operators' Group The task of the Operators’ Group is to ensure that the EIRENE System Requirements Specification (E-SRS) is harmonised with the Functional Requirements Specification and MORANE technical solutions (and subsequent

developments in the telecommunications standards). The Operators' Group is also responsible for handling issues raised by national implementation projects. This group is also responsible for the inter-working of the change control process. ETSI Project - Railway Telecommunications ETSI Project - Railway Telecommunications is responsible for the ETSI standardisation of railway telecommunication aspects. It will develop and maintain ETSI standards (as required) for application of GSM-R to railways as required by the European Directive on High Speed Train Interoperability and by other forthcoming European Directives for railways (including the European Directive on Conventional Lines interoperability). GSM-R Functional Group The task of the GSM-R Functional Group is to ensure that the solutions developed by the Operators' Group and ETSI Project - Railway Telecommunications are reflected accurately in the EIRENE Functional Requirements Specification. They are also responsible for the specification of new functions for railway operation such as GPRS.



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GSM-R Industry Group From the earliest days of the project MORANE, the industry has played a major role in the GSM-R standardisation process. The industrial key players, members of the GSM-R industry group, provide guidance to other bodies on the technical aspects and jointly support the promotion of GSM-R outside Europe. 1.3 Open Standards The GSM-R specifications and approved documents are openly available. The railway specific standards and related documents are available from the EIRENE web site.3

The Advanced Speech Call Items (ASCI) are now part of the ETSI International standards and attract much interest from public GSM network operators.

There are no proprietary elements in the GSM-R specifications. During the development of the standards, a series of test lines was constructed so that the inter-operability of equipment from different vendors could be tested and verified. Interoperability testing remains a core issue in the GSM-R approvals process. 2 AVAILABLE TECHNOLOGY 2.1 Built on GSM GSM-R technology differs very little from standard GSM technology. The core equipment for GSM-R is almost identical to

that for GSM and is in mass production. The mobile equipment has different packaging and some different software but the majority of the equipment design and software is identical with GSM handset and mobile design.

The core equipment for a GSM-R system consists of the Mobile Switching Centre, the Operation Sub-System and an Intelligent Network. There are many other core equipment elements but these are identical to the GSM components. 2.2 Mobile Switching Centre The Mobile Switching Centre for GSM-R is very similar to that for GSM. There is some additional processing for the GSM-R specific functions but otherwise the hardware is the same. The different vendors have slightly different implementations of the equipment. The Access Matrix is used in this process to determine any restrictions on connection and call paths.

A Virtual Private Network can enhance the flexibility of GSM-R, taking into account any prefix or the entire number for call permission screening. A Virtual Private Network permits the establishment of black lists and white lists, whereas the Access Matrix only has number group restrictions. The Intelligent Network has a great deal of capacity for railway specific applications. These sit outside the GSM-R standards requirements and therefore



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do not affect the capability of trains to work with other GSM-R networks. 2.3 Operation Sub-System The Operation Sub-System (OSS) is the same as the GSM equivalent. This system is used to manage and control the network. 2.4 Base Station Controller The base station transceivers at any site are controlled by a Base Station Controller. The Base Station Controller uses the GSM-R codecs with their very efficient voice coding. The voice circuits are normally trans-coded by the Transcoding and Rate Adaptation Unit (TRAU) to standard 64 kbps channels for transmission to the switching centre. There is scope to relocate the trans-coders to the switching centre and thereby reduce the transmission requirements for any base station. While this is not an issue if optical fibre is available, it can be a great advantage in many areas of Australia. 2.5 Base Station The GSM-R base station is very similar to a standard GSM base station. Each base station can handle a number of simultaneous calls. In lighter traffic areas the base station will normally be configured on a 1+1 basis, with one transceiver carrying live traffic and the other on standby.

The GSM-R base station cabinets often have battery backup built in. The battery backup usually only provides for around two hours of battery operation so many installations have a separate cabinet for larger capacity batteries. 2.6 Hand Held Terminals (Mobiles) There are two requirement levels for hand-held terminals. Most GSM-R users require a handset that is no more robust than a standard GSM telephone. There are GSM-R telephones for this environment that are similar to standard handsets, the significant differences being the emergency and press-to-talk buttons.

Train drivers, shunters, depot maintenance staff and other outdoors staff require terminals that are more robust. These terminals have to be suitable to be used with gloves and be able to operate in rain. The terminals frequently will be dropped.

Sagem Operational Handheld (Left) and General Purpose Handheld GPRS is available in some of the terminals. The availability of GPRS extends the usability and flexibility of the GSM-R network and provides a data transmission capability that could be put to good use in railway applications.

The GPRS functions can operate on the GSM-R terminals but are not available at the same time as the GSM-R features. The telephone switches into a different mode for GPRS operation and will not respond to the ASCI GSM-R features while in this mode. Sagem Terminals There are two Sagem portable terminals, one for normal use and the other for use where a more robust device is required. Both terminals implement the GSM-R features; the primary difference is in their construction. The General Purpose Handheld or GPH terminal is for use is shown below. The Operational Handheld or OPH has construction that is more rugged and is designed for use with gloves.

The General Purpose Handheld is designed for operation in normal environmental conditions. The telephone is of normal commercial construction and is similar in size to the larger GSM portables. This telephone



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operates in the full 900 MHz (GSM-R, E-GSM and public GSM) and 1800 MHz band.

The Sagem Operational Handheld is designed for operation in tougher environmental conditions. The telephone is of robust construction and is larger that standard GSM portables. One reason for the size is that the telephone is designed for use with gloved hands. The Operational Handheld has an IP54 rating for dust and moisture ingress. Marconi Terminals The Marconi terminals have recently been developed and have some additional features. There are two main models, the General Purpose Handset and an operational Handset.

Marconi Operational Handheld The Marconi RGG (Railway General Purpose GPRS handheld) product is a standard GSM mobile, designed for general railway use. The services that this mobile offers include GSM Phase2/2+ services for data transmission, GPRS services, browser WAP applications and the specific GSM-R services 2.7 On-Train GSM-R Equipment Most of the GSM-R on-train equipment has been designed for use with ETCS for train control applications. The format of the on-train equipment is generally a Eurocard module and a number of modules are intended to fit in one or more Eurocard racks.

Marconi General Purpose Handheld Sagem supply a GSM-R locomotive module that is incorporated into the locomotive equipment from Nortel. The module is designed to plug into a Eurocard frame (3RU).

Sagem Locomotive GSM-R module

Marconi manufactures several GSM-R modules. The Marconi RMM2200 is a standard GSM-R vehicular radio for on-train use. This standard module works in the GSM-R band, including the Public GSM (P-GSM) and Extended GSM (E-GSM) bands. This module is in the same Eurocard format as the SAGEM unit. The Marconi RMM4200 is a standard EIRENE/MORANE radio for fixed application use. The significant difference between this module and the RMM2200 is that this module operates from a single 5V supply with a maximum output power of 4W.

The RGM (Railway General Module) is a small 2W GSM-R module that provides voice,



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data, GPRS, phase 2+ ASCI and the EIRENE features for integration into other equipment. The module operates at 2 W or 1 W with a receiver sensitivity of -102 dBm. This module operates in the 900 and 1800 MHz bands.

Marconi Model RGS100 GSM-R Module

The ESVM (External Serial Voice Modem) is a small 2W GSM-R module to provide voice, data, GPRS, phase 2+ ASCI and the GSM-R features. 2.8 GSM-R Cab Equipment One of the great difficulties for railways implementing GSM-R is dealing with the transition period. One option is to build the entire GSM-R network and then progressively change the locomotives from the existing system to GSM-R An alternative is to fit the locomotives with both GSM-R and the existing system during the transition.

Dual mode radios, capable of operating on the existing analogue system and GSM-R are being used by some railways.

Marconi EVSM100 GSM-R Module

The German Railways operate a dual-mode system, with both GSM-R and UIC-753 (the existing radio system) functionality.

The driver panel has been designed to simplify the transition from the existing analogue system to GSM-R and then to electronic signalling with the European Train Control System (ETCS). The driver interface on the panel (pictured below) uses icons and functions that have been adopted as a part of the human interface for the ETCS project.

Other railway operators use a standalone GSM-R system on the train with either graphical or textual-based drivers panels. For example, NS Reizigers in the Netherlands use a cassette mounted cab radio from Siemens, which is a direct mechanical replacement on their existing analogue radio.



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Siemens GSM-R Cab Radio 2.9 Train Controllers and Signallers The GSM-R specifications do not discuss train controllers and signallers (dispatchers) in very much detail. The writers of the specifications were of the view that the equipment used by the dispatchers has no impact on the international interoperability of trains and therefore did not specify the equipment configuration or style. The GSM-R network and system has been designed so that an ISDN telephone can provide all the facilities that are essential for a dispatcher.

Frequentis "Dicora" GSM-R signaller/train controller terminal

While a GSM-R telephone is sufficient for a dispatcher to operate GSM-R, it is certainly not convenient and would not be practical at any busy control or signalling location. As railways have started implementing GSM-R, they have realised this and have started specifying their requirements for GSM-R dispatcher equipment. The German Railways were the first to identify this problem in a system rollout.

An Austrian company, Frequentis has developed a range of equipment for GSM-R dispatchers. This equipment has been used by DB for their GSM-R systems. The Frequentis equipment is based on an ISDN telephone and has a touch screen computer display to improve the interface. The user interface has been designed in consultation with the DB operations staff.

Siemens Touchscreen GSM-R Dispatcher Terminal

Siemens GSM-R Radio Dispatcher Terminal Most of the equipment suppliers offer a model that incorporates a GSM telephone. With this a dispatcher to be established at any location and (to some extent) can be independent of the fixed network. This model is very attractive as a solution that can easily be installed without the need for infrastructure.



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3 APPROVAL 3.1 Approval Process The European Union has a procedure for certifying compliance with its standards and regulations. A part of that procedure requires member states to notify the other member states of the bodies responsible for carrying out the procedures for assessment of conformity or suitability of systems/equipment for use. These are known as “Notified Bodies”. One such notified body is the German organisation EBC. It works in conjunction with the German approval authority (EBA).

A Notified Body must assess the safety, reliability and availability, health, environmental protection and technical compatibility of each system that it evaluates. In addition, for GSM-R equipment the notified body will check for interoperability and will perform an audit of the quality management of the designers and manufacturers.

The tests by the Notified Body will normally consist of paper audits, laboratory tests and field tests.

3.2 Interoperability GSM-R has been based on interoperability from the outset. There is a series of tests by the manufacturers of their own equipment against the standards. Then the equipment from the manufacturer goes through the Notified Body testing phase. In addition to this, there is the positive test of field use.

The mobile equipment is required to work with the base station and control equipment of each manufacturer. The interoperability is demonstrated on any trip that crosses implementation contract boundaries. Neither manufacturer of network equipment manufactures the mobile terminal equipment so there is a reduced risk of incompatible software or design being introduced into any installed system.

4 CONCLUSION GSM-R is a viable, purpose built railway radio communication system. It has extremely advanced features and uses equipment that is multiply sourced.

With the whole of Europe involved in GSM-R, the standards and systems will be maintained and have a development path.

There is a defined approval process for GSM-R equipment to be assessed against internationally accepted standards. Notified Bodies have been identified to independently assess the compliance of equipment. GSM-R equipment is on the market, in large-scale production and GSM-R is in service today.

John Aitken BE Director, Aitken & Partners Consulting Engineers John Aitken has been associated with train radio in

Australia over the last twenty years. His largest project was the development of Countrynet in (NSW), pioneering the use of GPS and satellite telephone systems for railways. This was followed by the Pacific National AWARE locomotive system and the Communications Control Centre (CCC) project. Experience with

railway radio and passenger security systems in NSW, Queensland, Victoria and Western Australia has reinforced his enthusiasm for systems that are based on international standards. John has a particular interest in human factors and systemic issues in railway communications.



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Martin Lehrbaum, MSc. GSM-R Sales and Marketing Nortel Networks Martin Lehrbaum has a Senior Management role within

Nortel Networks, focused on GSM-R. His primary interests are in developing new markets for GSM-R throughout the world and enhancing the existing Nortel market relationships. Through his extensive customer interaction and knowledge of customer requirements Martin has become involved with the GSM-R product

development strategy and architecture. Over the last year Martin has been leading the customer marketing team for Germany, the biggest GSM-R project awarded worldwide so far. This project has revealed many of the issues (both technical and operational) that are faced by early implementers of a new technology.

Glyn Owen Marketing Manager GSM-R Siemens Transportation Systems Glyn Owen has spent 25 years working on railway

projects for Plessey and Siemens Transportation Systems. Projects have included Transponder Systems for the Advanced Passenger Train, Signal Post Telephone systems and Track to Train Radio systems in the UK and overseas. Glyn was the systems design manager for the Metronet train radio system in Sydney.

Glyn was involved in the initial work on GSM-R by Siemens Transportation. Glyn represents STS within the GSM-R INDUSTRY GROUP, is deputy speaker of the Technical Group, and is involved from the industry side in the task of updating and controlling the GSM-R specifications. 1 M Watkins, http://eirene.uic.asso.fr/eirene.html 2 http://eirene.uic.asso.fr/mou.html 3 http://eirene.uic.asso.fr/specifications.html

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