An Advanced Satellite UMTS Testbed for Laboratory and Over-the-Air Experiments of Third Generation Mobile Services

This paper provides an overview on the Advanced S-UMTS Test Bed (ATB) project funded by the European Space Agency (ESA), which was instrumental to define, validate and demonstrate the adaptations of third-generation (3G) mobile technologies based upon Wideband Code Division Multiple Access (W-CDMA) for supporting via-satellite services. Such services are often generically referred to as Satellite-UMTS (S-UMTS). One of the main project targets was to develop and demonstrate, both in the laboratory and over-the-air, a set of technical solutions for the efficient provision of point-to-point (i.e. interactive) and point-tomultipoint (i.e. multicasting / broadcasting) services, so as to best exploit the precious satellite communications resources. After dwelling on the aims of the ATB project, the subject paper presents the key required adaptations and extensions, for satellite applications, to the W-CDMA scheme as standardized by the 3 Generation Partnership Project (3GPP) for terrestrial applications. The paper then continues on by describing the architecture of the real-time endto-end Test Bed (taking the name ATB after the project name) which was developed with the main objective of supporting both laboratory and over-the-air trials, and of its main constituting elements.