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Integrated Confined Area RTI communication system

Objective

The objective of the project is to investigate the use and feasibility of a transparent GSM RTI system radio coverage from open areas to confined areas and to make recommendations which lead to the use of a pan-European GSM radiating retransmission system into confined areas.
An investigation of the use and feasibility of a transparent Groupe Special Mobile (GSM) road/rail transport informatics (RTI) system radio coverage from open areas to confined areas is taking place and recommendations are being made which will lead to the use of a pan European GSM radiating retransmission system in confined areas.

The technical approach studies the problems inherent to the retransmission of the pan European Cellular (GSM) mobile communication systems into confined areas.

The work has:
studied the possibility of extending the GSM RTI and the system of cellular radio for traffic efficiency and safety (SOCRATES) road/vehicles digital communication systems to the coverage of confined areas;
theoretically demonstrated the feasibility of a GSM confined area radio coverage using the approach of a booster station;
developed new industrial high performances leaky feeders and mode converters working in the GSM radio frequency band;
conducted preliminary field trials to evaluate the performances of these leaky feeders and mode converters on a 900 MHz retransmission system in confined areas;
verified that the bit rate capacity of the channel at 900 MHz in confined areas is consistent with the 270 kbps needed by the GSM technology;
explored theoretically the potential advantages of using a fibre optic backbone to directly feed the radiating equipment;
continued the study of some critical parameters such as handover procedures.
Technical approach

The technical approach studies the problems inherent to the retransmission of the pan-European Cellular (GSM) mobile communication systems into confined areas. Confined areas relate here to either tunnel, viaducts, underground parking lots.

GSM retransmission in these areas is a problem of major importance since communication interruption in RTI applications based on cellular radio has to be avoided. The integration of confined areas retransmission equipment in the cellular network leads to technical choices concerning two levels :

a. How to integrate tunnel retransmission equipment in the cellular network.

Two different approaches exist: the first one requires an additional cell (with its own Base Transceiver Station connected to the Mobile Switching Centre) specifically dedicated to the confined areas radio coverage. The second one consists to use a system which extends the cell's limits into the tunnel. This second approach is specifically studied in ICAR.

b. The radiating element used to radiate the energy in the tunnel.

Technical candidates to radiate GSM signals at 900 MHz in confined areas are either conventional (directive) antenna(e), leaky feeders or mode converters.

It must be pointed out that these two levels are totally independent, e.g. leaky feeder, directive antennae or mode converters can be used whatever the solution adopted to integrate the system in the cellular network is.

Key issues

Communications technology for the IRTE;
GSM - RTI standards;
New GSM radiating devices developed by the European industry for confined areas applications;
Confined areas GSM radio retransmission system study;
Standardisation of GSM radio systems in confined areas;
Confined areas field tests evaluation;
GSM radio channel characterisation.

Expected achievements

The work will now:

evaluate the performances of the newly developed leaky feeders and mode converters at 900 MHz and 1800 MHz (DECT) in confined areas;
assess the possibility of extending to confined areas the retransmission of digital signals at frequencies up to 1.8 GHz;
contribute to standards.

Expected impact

The main purpose of ICAR is a feasibility study and demonstration of a high rate data communication link using GSM cellular radio into confined areas as a medium for the IRTE.

The expected impact relates to the two levels previously mentioned:

a. How to integrate the tunnel retransmission equipment in the cellular network.
b. The development by the European industry of radiating systems able to radiate GSM signals at 900 MHz and possibly in the L band (1.8 GHz) inside confined areas.

Contribution to Standards

The relevant contribution deals with the standardisation of the physical layer of high rate digital radio transmission links in confined areas.

The consortium will deliver technical contributions on the system approach and on the products approach (ETSI SMG 2 and IEC SC 46X A).

Coordinator

Institut National de Recherche sur les Transports et leur Sécurité (INRETS)
Address
20 Rue Elisée Reclus
59650 Villeneuve D'ascq
France

Participants (5)

AEG KABEL AG
Germany
Address
Bonnenbroicher Straße 2-14
4050 Mönchengladbach
ALCATEL CABLE
France
Address
35 Rue Jean Jaures
95871 Bezons
ISSEP
Belgium
Address
200,Rue Du Chera
4000 Liege
Sirti SpA
Italy
Address
Via E. Fermi 2
20060 Cassina De Pecchi Milano
Université de Lille I (Université des Sciences et Technologies de Lille Flandres Artois)
France
Address
Bâtiment P3 Cité Scientifique
59655 Villeneuve D'ascq