Research On The Reliable Transport Technologies In The Broadband Satellite IP Communication Networks

In satellite communication, broadband satellite communication is focused on providing ubiquitous communication mode for multimedia and high bit rates Internet application. The satellites have very great advantage for that high speed data services with low time delay requirement and broadcast/multicast character (for example, the large pipe data transport, multimedia broadcast, broadband access of Internet, satellite remote application and bidirectional interactive multimedia, and so on). The broadband satellite networks could be named next generation satellite networks. They have traits as wide area coverage, bearing many kinds of application, deploying quickly, high bandwidth utilization, fast on-board switching and providing integrative network, etc. Developing the broadband satellite systems has become one of the new communication hotspots.Internet grows very fast; all kinds of network technologies develop to provide high quality IP service. Satellite systems have the inherent advantages of wide area coverage, and long distance transmission; so it is the important direction of communication development that combining with satellite and IP technology.TCP is the transport protocol of Internet application. TCP is designed for terrestrial wire networks; in satellite environments, it will appear long time delay, high bit error rate, and forward/reverse channel asymmetric, and so on; so it should be solved and could work well.The satellite systems have inherent advantages of unique broadcast capability, and it is very fit for multicast service. Along with the development of multimedia service on internet, LEO networks need to guarantee QoS. The multicast and QoS routing are the key technologies of satellite networks reliable transport.ISL (Inter-Satellite Link) is the bidirectional communication thoroughfare between satellites. The adoption of ISL can reduce the system ground segment cost, and improve the agility of space segment. ISL design in formation flying is the key point, and influences the system performance directly. In order to realize the reliable data transmission in formation flying ISL, the protocol of low layer is the core.This dissertation mainly focuses on reliable transport technology in broadband satellite IP networks, which includes TCP congestion control strategy, reliable multicast transport technology, QoS routing algorithm design, and reliable data transmission scheme of physical/link layer. This dissertation has contributions as follows:1.Proposes two broadband satellite TCP solution schemes: based on priority satellite TCP and satellite intelligent TCP congestion control stategy. The simulation results indicate: these two schemes improve the system throughputs markedly, at the same time, achieve fair share of network resources in heterogeneous scenarios.2.Presents a reliable multicast transport protocol based on agent.The protocol realizes satellite multicast by using agent of receivers. Packet FEC and ARQ are used. The congestion control is implemented by different priorities packets. It solves some key problems of reliable transmission in satellite networks. Algorithm has expansibility.3.Proposes a distributed multicast routing algorithm for LEO networks.The simulation results indicate this algorithm can achieve shorter end-2-end delay and multicast tree length and keep lower cost.4.Brings forward a distribute QoS routing policy based on heuristic ant algorithm. It gives the guarantee-channel scheme that achieves high priority of handover under the fair condition. The simulation results indicate it has lower call blocking rates. The cost is lower under higher load.5.A study has made on a reliable transmission scheme that deploying UWB technology into formation flying. It gives the system link budgets and the method that how to positioning the satellites, analyzes system throughput of MB-UWB ISL scheme.The results indicate the scheme has feasibility and good performance.