Provision of multimedia services over Europe by means of geostationary satellites with multispot coverage using small terminals

Abstract

The possibility to provide multimedia services over a wide area using small mobile terminals represents a challenging task. This task is even more challenging especially if high frequency bands are used and high service availability is required, considering that the atmospheric conditions are very severe and geographically variable within a wide area. The use of high frequencies is necessary to provide wideband services at high data rate for a large number of users and the link availability has to be comparable with that provided by other systems working at lower bands. In the frame of the Advanced Communications Technologies and Services program of the European Union a team of thirteen partners is working since September 1995 on the design of a satellite system named SECOMS (Satellite EHF COmmunications Multimedia Services) (Losquadro and Vatalaro, 1995; Losquadro, 1996). The system aims at providing multimedia services by means of GEO satellites utilising set-top or palm-top terminals working respectively at Ka-band (20/30 GHz) and at EHF-band (40/45 GHz). Within the SECOMS project the problems mentioned above have been studied in depth and the main system parameters have been finalised. This paper aims at a description of the main system characteristics of the SECOMS project and suggesting a design approach for satellite systems providing multimedia services to mobile users. The proposed approach consists in providing an adjustment (static or dynamic) of the satellite EIRP among the spot beams to get the same link availability within the coverage area using the same terminal, considering that the distribution of rain fade statistics depends on the location. To this aim several technical solutions can be adopted.