HARRIS DELIVER DECODERS TO TDF

HARRIS Broadcast Europe (HBE) has delivered 150 additional decoders to TDF(Télédiffusion de France) for feeding synchronous FM transmitters via satellite.
The transmitters enable motorists in France to receive a mix of entertainment and traffic information over a single VHF channel without the need to re-tune their receivers during long drives across geographical regions.
Part of Harris Broadcast Europe, ITIS Products have been working with TDF to improve the synchronous FM systems along French motorways for two years. Harris initially provided two uplink chains and 237 synchronous FM decoder units, and has now completed the delivery of an additional 150 decoders which will be installed by the end of 2001 along the motorways managed by ASF (Autoroutes du Sud de la France) and SAPRR (Société des Autoroutes Paris-Rhin-Rhone). This batch of decoders is the fifth order placed by TDF for this product, which was specifically developed by ITIS Products for this application.
Digital synchronous linear FM broadcasting for motorway radio was developed by TDF. It is based on very precise timing between contiguous transmitters, so that interference is minimised when the receiver in the car is midway between two transmitters. With the TDF system, the zone of interference will be no more than a few metres, which drivers will not notice because the car is moving and any problems disappear before the listener detects them.
Achieving precise synchronisation between transmitters in this application is essentially very similar to the demands of single frequency networks in DAB and DVB-T, areas in which Harris is a world leader. The process involves adding synchronisation codes to the digital distribution stream, and equipping the transmitter decoders with GPS receivers.
Pierre Crespi, technical manager,TDF said: "Two years ago we decided to use satellites feeds to the transmitters. Harris had done the coding and multiplexing parts of this technology, and won the contract because of its knowledge of Eureka 147 technology and the quality of its MPEG encoders. The Harris equipment ensures very precise control of the overall time delay between the source and each transmitter." (GB)