Resource Management in Satellite Networks part 6. This book provides significant knowledge on innovative radio resource management schemes for satellite communication systems that exploit lower layer adaptivity and the knowledge of layer 3 IP QoS support and transport layer behavior. The book integrates competencies considering all the parts of system design: propagation aspects, radio resource management, access protocols, network protocols, transport layer protocols, and more, to cover both broadband and mobile satellite systems | Chapter 1 INTRODUCTION TO SATELLITE COMMUNICATIONS 27 Fig. The four possible DVB-S2 constellations before physical layer scrambling. Numerical details on the selected scenarios for performance evaluations This sub-Section provides some basic characteristics and numeric values for the parameters that have been used when evaluating the performance of the techniques proposed in the following Chapters of this book for the different scenarios. The details are provided below. Scenario 1 S-UMTS as well as S-HSDPA GEO satellite Multi-spot-beam satellite antenna Bent-pipe satellite Terrestrial gateway containing the scheduler MAC layer Direct return link via satellite for channel quality measurements in case of point-to-point services Mobile users mean speed equal to 60 km h GOOD-BAD Markov channel model typically 6 s mean GOOD duration and 2 s mean BAD duration 29 IP-based traffic flows with UMTS transport layer encapsulation Traffic sources video sources sum of ON OFF Markovian sources 30 and Web sources 2-MMPP arrival process of Pareto-distributed datagrams 31 . 28 Giovanni Giambene Scenario 2 DVB-S DVB-RCS GEO satellite Single beam or multi-spot-beam satellite antenna Bent-pipe satellite Architecture involving an NCC and at least a GW Fixed users Direct return link for channel quality measurements typically Ka band is used maximum capacity 2 Mbit s Forward link in K band Channel model only troposphere effects rain scintillation and gas have to be considered. Basically an Additive White Gaussian Noise AWGN model has been adopted with a given packet error rate uncorrelated losses IP-based traffic flows with MPE encapsulation and generation of packets according to the MPEG2-TS format Traffic sources of the FTP type elephant TCP connections . Scenario 3 LEO constellation A Teledesic-like LEO system the Boeing design with 288 satellites altitude of 1375 km and satellite capacity of 32 Mbit s Multi-spot-beam satellite antenna End-users must switch from spot-beam to
