Location Management And Routing Algorithm For Leo Satellite Systems

The excellent location management scheme can reduce the system cost and improve the performance of the Low Earth Orbit Satellite Mobile Communication System. Location management includes location area design and page scheme. Besides, the routing algorithm with inter-satellite links is also very important in LEO satellite mobile communication system, adopting the proper algorithm can improve the quality of service and make the network more stable of the satellite system.In this dissertation, both location management technology including location area design and page strategies and routing scheme with inter-satellite links in LEO satellite communication systems are studied in detail. This dissertation gives the detail discussion in the following chapters.Chapter 1 gives brief introduction of LEO satellite mobile communication system and the current situation of the location management technology and the routing algorithm.In chapter 2, the schemes for both fixed location area design and dynamic location area design based on user's mobility in LEO satellite system of which users have independent positioning capabilities are studied. By comparing user's location management cost with different MT's mobility, it shows that the dynamic location area scheme is more suitable for user; we also compute the size of location area for two types of specific velocity.In chapter 3, the paging schemes of the LEO satellite mobile communication system have been studied. Combine with the modified user movement model, a paging strategy is presented based on the dynamic location area. It can reduce the page cost with delay constrain for high speed MT and improve the system performance.In chapter 4, the schemes on routing algorithm with inter-satellite links for LEO satellite communication system are introduced and the Delay Constrained Least Cost Algorithm is proposed. The simulation results indicate that the parameters such as original call block probability, handover failure probability are compared and some valuable results have been obtained. At last, the priority of the new strategy is analyzed.In chapter 5, the dissertation is summarized and point out the future work which need to have detail research.