Location Management In Leo Satellite Communication Networks, Strategy And Simulation Platform Design

Currently, low-earth orbit (LEO) satellite communications becomes one of the hot issues in communication studies due to its numerous advantages. With the development of LEO satellite communications, however, it is confronted with the same problem as the public land mobile communications. That is the increasing number of subscribers and the increasing demand for high quality of the network, which is a challenge for the mobility management in the LEO satellite network. Traditional mobility management technology hardly meets the needs of the subscriber. So the mobility management strategy of LEO satellite network should be optimized and improved. Moreover, Due to the particularity of LEO satellite communication system, such as the long period and the huge funds needed in the construction and the difficulty to change the structure after the construction, the precise simulation before the implement of the LEO satellite network is necessary. So the satisfying simulation method is in need urgently.In this paper, an improved location management scheme is put forward according to the traits of LEO satellite network. It focuses on the two parts in designing the new location management model: the location update and paging. Moreover, considering the scheme presented in this paper, I set up a simulation platform based on OPNET.In chapter one, I describe the related techniques in location management and the development of it nowadays. Then the brief introduction of the special traits of LEO satellite network is presented.In chapter two, the main task is optimizing the location update method, decreasing the cost of location update while not increasing the cost of paging in location management of the system. I propose a pointer forwarding and regional registration based dynamic (PFRRD) location management strategy for satellite networks. I introduce the concept of dynamic regional location area (RLA) and sub-region location area (SRLA). Combining the advantages of pointer forwarding and dynamic location management, this strategy can effectively reduce the cost of location update.In chapter three, I focus on reducing the cost of the paging part in location management, through which the optimizing of location management comes true while not increasing the cost of location update.In chapter four, I introduce the distinct advantage of the OPNET simulation software in supporting the satellite orbit. The STK orbit can be added into the OPNET simulation platform, through which the accurate simulation is available. Moreover, the other different strategies of mobility management can be validated on the platform to improve the performance of the mobility management in LEO satellite network.