Satellite-Digital Sound Broadcasting terrestrial repeaters network planning: a study by ATDI for Alcatel Space and WorldSpace

February 2003

WorldSpace, the first global operator of satellite digital audio broadcasting systems and Alcatel Space, the world leader in the design and manufacture of satellite DAB technologies, signed in 2001 a strategic partnership agreement to develop a space-based digital sound broadcasting system for Europe.

Both companies expect the planned system to provide seamless coverage over the European continent, offering programs of crystal-clear quality to users with mobile (in-car), fixed, and portable radios.

As any other satellite technology, S-DSB requires a clear line-of-sight between the satellite and the receiver. But sometimes, it happens that obstacles block the satellite signal reception. For example, in urban areas, the buildings can hide the satellite to the receivers located on the roads and prevent a correct reception of the signal. In that case, it is necessary to install terrestrial repeaters to relay the satellite signal around the obstacle. The number of these terrestrial repeaters is of course a key figure in the estimation of the global cost of the service.

Alcatel and WorldSpace requested ATDI to identify the areas in France where terrestrial repeaters were required and to estimate their number as well as their technical characteristics.

First, the coverage of the satellite was calculated over the whole country. Not surprisingly, it appeared that the urban areas were not covered, because of the buildings, but also some high altitude areas, because of the mountains.

Then, a detailed repeaters network planning was performed on three cities of reference (Paris, Nantes and Boulogne-sur-Mer), using a high-resolution cartographic dataset.

And finally, these results were extrapolated on the whole France, with a medium-resolution cartographic dataset, in order to cover the most important urban areas, that is to say the ones with a population above 50000 inhabitants.