An Advanced Satellite UMTS Testbed for Laboratory and Over-the-Air Experiments of Third-Generation Mobile Services—Part II: Experimental Results

This paper complements its companion paper by reporting the key experimental results obtained both in the laboratory and via satellite, using the Satellite Universal Mobile Telecommunication Systems (S-UMTS) Advanced TestBed (ATB) - a comprehensive facility developed under a European Space Agency contract whose intention was to demonstrate a set of technical solutions for the efficient provision of the so-called S-UMTS services, i.e., third-generation (3G) point-to-point (i.e., interactive) and point-to-multipoint (i.e., multicasting/broadcasting) mobile services based on wideband code-division multiple access (W-CDMA). After addressing the architecture of the overall via satellite ATB demonstrator, the main test results obtained in the laboratory, as well as over the air, are summarized. Then, bit error rate and frame error rate measurement results that were taken from the forward and return links are shown for both the additive white Gaussian noise and the Ricean channels, with different orders of space diversity and different coding schemes, which were classified as either convolutional or turbo 3G partnership project coding. Finally, key results of via satellite L-band measurements are reported for both unicast and reliable multicast applications. Because of the extensive test campaign presented in this paper, the viability of adapting W-CDMA to support point-to-point (packet) and point-to-multipoint multicast services in the satellite environment, as standardized by the European Telecommunications Standards Institute, has been widely validated and experimentally confirmed. Reliable multicast techniques, exploiting a forward error correction that operates at the upper layer, were shown to be a powerful way of counteracting satellite channel impairments, thus allowing the multicast of multimedia contents in quasi-real time with good quality of service.