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Resource Management in Satellite Networks part 5

Resource Management in Satellite Networks part 5. 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 17 MPEG2-TS are of the TDM type. In the channel adaptation section packets are processed in several steps such as channel encoding outer Reed-Solomon coding convolutional interleaver inner convolutional encoding puncturing base-band shaping of impulses and QPSK modulation. The resulting DVB-S transmissions via satellite are very robust considering a minimum BER of about 10 1 11. As an example a typical data rate of about 38 Mbit s is obtained with modern satellite transponders that have a bandwidth of about 33 MHz 13 . 1.4.3 DVB-RCS standard One of the reasons for the definition of a DVB standard with satellite return channel DVB - Return Channel via Satellite DVB-RCS has been the increasing request of interactive applications and services with major informative volumes 1 that could not be achieved with a DVB-S-based system where the return channel realized through a terrestrial link via modem cannot permit an adequate bit-rate capacity maximum 64 kbit s . The specifications of DVB-RCS use and modify the DVB-S ones 14 15 moreover they are independent of frequency making easier to realize network and security mechanisms with an efficient transport layer. The DVB-S channel has been named Forward Channel while the Return Channel is related to the link from the end-user back to the content network see Figure 1.4 . The return channel has a variable bit-rate up to a maximum of 2 Mbit s and can dynamically assign its time-frequency resources according to an MF-TDMA air interface to the requesting terminals. The Return Channel Satellite Terminal RCST transmission capacity is constrained. According to the standardization RCSTs can be single-user 144-384 kbit s or corporate 2 Mbit s . The standard 14 15 defines a reference model for the Interactive Satellite Network ISN architecture composed of a certain number of RCSTs a GEO bent-pipe satellite and the following elements Network Control Center NCC it provides Control and .