Finalising the Swedish GSM-R project
Posted: 23 August 2005 | | No comments yet
Despite difficulties and eight years after its start, Banverket is about to finalise the Swedish GSM-R project SIR. Problems solved have included appeals against building permits for radio sites, interaction problems between phones and the Swedish GSM-R network and difficulties achieving full system functionality according to the EIRENE specifications.
When Banverket (The Swedish National Rail Administration) started the SIR (Swedish International Railway radio) project in 1997, it did so as the first railway operator in the world and was consequently a pioneer in the area.
The Swedish GSM-R network MobiSIR (Mobiles in SIR) is now practically built out with approximately 800 sites along the entire Swedish main-line railway network, which consists of almost 500 kilometres of railway (including tunnels) out of a total of approximately 10,000 kilometres. The remaining 2,500 kilometres are low traffic lines, due to be equipped with MobiSIR during 2006 and 2007. When this sub-project is completed, all communication for railway operations will run on MobiSIR.
The EIRENE functionality
At present, verification of radio coverage and functionality in accordance with the EIRENE specifications is carried out by way of measurements on the main-lines, which is quite an extensive effort. When the verification of the radio coverage is completed and possible areas with poor coverage have been attended to, this part of the specifications will be fulfilled.
The functionality is not yet fully in accordance with the EIRENE specifications. This means that new software with increased functionality has to be installed to obtain the desired functionality.
The work with connecting MobiSIR with other GSM-R networks in Europe has begun and an initial point-to-point call (between two subscribers) with the German GSM-R network has been carried out.
At present, call measurements indicate a steadily increasing use of MobiSIR. The largest increase in the number and length of calls is taking place in MobiSIR and not in the connected public networks.
MobiSIR is dimensioned for hand-held radio coverage along the railway and for calls between engine-drivers and train control. This includes supplying on board staff with GSM-R hand held devices. These require the presence of repeaters on board carriages because of the high attenuation caused by their metallic bodies. Modern carriages attenuate radio signals to such a great extent that a contact between mobile equipment in a carriage and MobiSIR is, in principle, impossible without repeaters. Once repeaters have been installed in approximately 1,000 carriages, the on board staff will be able to use a number of different applications helping them to supply passengers with increased services in a simple and convenient way.
The services in MobiSIR are in accordance with the services standardised in the EIRENE specifications. The various call types with different priority levels are implemented and function according to the specifications. However, shunting radio has not yet been implemented in the system, mostly on account of the tests of the phone used for this application not yet being completed and also as a result of poor demand from the railway companies.
Trains for international traffic are normally equipped with the mobile terminal CAB 2, which has an 8 W output power, while domestic trains – to a great extent – use a phone with 2 W output power (OPH 940), which is sufficient since MobiSIR is dimensioned for mobile terminals/phones with that very output power. Office personnel use the phone MyX5-R, which does not contain ASCI features.
Roaming agreements with two public GSM operators allow all MobiSIR phones to use those public networks and, in addition, trains equipped with GSM-R phones are able to register themselves with functional numbers. In that way, they can be reached through their functional numbers on lines within the public networks. Deregistration of functional numbers can also be made in the public networks.
Apart from the fact that MobiSIR is able to provide satisfactory functionality for safe railway operation, the system is open to new railway-related applications. Of course, there are physical limitations regarding, for instance, the system’s bandwidth, but apart from that, there are great possibilities of complementing the functionality with different applications, aiming at improving and simplifying for both railway staff and passengers. At present, there are a number of different applications in MobiSIR – either in operation or existing only as prototypes.
Intranet, Internet and e-mail (in operation)
MobiSIR is connected to Banverket’s internal network through GPRS. This implies that users of MobiSIR phones, equipped with GPRS, have access to Banverket’s intranet (including Internet and e-mail). Users outside Banverket’s organisation – through Banverket’s firewall – also have access to Internet.
KIKA is a carbon strip camera detecting faults in the contact strip by taking a photo of the pantograph on each train passing by. The photo is analysed on the spot by computer and, in the case of serious damage on the carbon strip, an alarm as well as the photo are sent via GPRS to Banverket’s operation management centres, which forward the alarm to the engine-driver. At that point, the photo is compressed and only the parts reproducing the pantograph’s carbon strip are in high resolution. At a later stage, the photo is analysed.
Hot box and hot wheel detection (in operation)
Each year, approximately 200 hot box detection alarms and some 1,500 wheel detection alarms are received by Banverket’s operation management centres. If these alarms aren’t detected at an early stage, this may have devastating consequences, for instance derailments. The cost of repairing the rail may amount to several million euros for each derailment. To be able to increase the number of detectors in a cost-effective way, an application using GPRS as a bearer of the information is being tested. The advantage of using GPRS is the ability to locate the detectors anywhere along the tracks and, consequently, does not have to depend on fixed cables, such as copper cables.
Passenger information displays (in operation)
In a number of places in Sweden, passenger information displays, showing primarily departure and arrival times, are being installed. These displays are located on platforms and in waiting rooms where the information is updated via GPRS by means of Banverket’s data system.
Supervision of railway installations (prototype)
An application for supervision of railway installations presently being tested in approximately twenty places in Sweden has been developed as a preventive measure. The purpose of this application is to obtain information about position of points and the possible need for electric heating of points due to low temperatures and humid weather, which may cause problems if these points freeze.
RFID (Radio Frequency IDentification) (in operation)
An extension of the existing system for identification of carriages will be tested with an application based on use of GPRS instead of, as today, a fixed connection. The use of GPRS offers railway companies greater flexibility in connection with the location of the reading-points, while the total cost of the applications is expected to be significantly reduced.
In the north of Sweden there are large herds of reindeer, and in an attempt to reduce the number of reindeer killed by trains, an application ‘counting’ the animals in certain places along the railway is being tested. The experiment shall not be regarded as scientific, but the principal aim is to locate the herds, especially since they move across large areas criss-crossed by the railway.
All applications in MobiSIR are supervised by use of a PING command. By using this command, one makes sure that the applications at a certain level are running as expected. In addition to that, applications for hot box and hot wheel detection are supervised by means of a specially designed presentation system, in which the result of the detection is presented in a standardised way and with a uniform user interface.
MobiSIR itself shall not be considered as a security system for all applications. Each application shall be executed so that it automatically ends up at a security level in the event of a possible failure in MobiSIR.
Customer support is taken care of within Banverket’s own organisation. By means of different support systems for reporting faults, the support organisation is able to provide the customers with prompt answers to their questions. The support organisation also has access to different systems, such as OTA (Over The Air application), which helps to administer and update the customer services, stored on SIM cards. MobiSIR and all sub-systems, including transmission, are supervised twenty-four hours a day.
In Sweden, we have just begun to see the opportunities GSM-R offers as a system with a functionality based on the EIRENE specifications valid today. These specifications will very likely be upgraded because of technical advancements and the demands of different railway operators in Europe.
An increased use of the system will probably increase and change the requirements for the system functionality and coverage. Today, there are approximately 1,200 subscribers in MobiSIR and the railway companies have just begun to use the basic functions.
Of course, the system’s bandwidth may limit expansion, but apart from that, there are great possibilities of complementing the functionality with different applications – either by using closed-circuit coupled technology or by utilising GPRS.
The introduction of ETCS, with its specific requirements for, among other things, accessibility, will probably also influence the future use of GSM-R. The use of GPRS may also be the subject of discussions concerning the train control itself as well as control of objects along the railway.
The number of applications with both closed-circuit coupled technology and GPRS will very likely increase. The question is; at which point will maximum system capacity be reached as a result of the system’s technical limitations (frequencies, bandwidth et cetera)? Use of single mode and EDGE technology may be necessary earlier than expected. He who lives will see!