Research On Qos Guarantee Mechanism In Space-ground Integrated Network

As a critical infrastructure and means of space communication and exploration, the space tracking networks has always been hampered by the space agency's attention in each country. Since the development of Internet technology provides a new way for space communications, the current study is focused on the application of successful technologies in the Internet to space communications and the constructing of space-ground integration network. In this dissertation, the internetworking protocols and architecture of space-ground integration network are studied, as well as the QoS guarantee mechanism of Internet and the mobile IP handover scheme that brings about better handover performance between low-orbit spacecraft and ground stations. The main results obtained in this paper are as follows:In this dissertation, the overall design and conceptual structure of space-ground integration network are given, so it is with the hierarchical network architecture and the networking protocols. On this basis, a MIPv6 handover scheme that can highly improve the handover performance is proposed, namely the MIP handover scheme based on orbit information predetermination. The defects of applying conventional MIP technology directly to space communications are analysed, followed by the handover procedure of the data link layer and the network layer. And then, the handover performance improvement of the new handover scheme is analyzed in detail, which is simulated and validated by the combination of STK and OPNET modeler further.The research on the QoS guarantee mechanism of space-ground integration network is given. The data link layer protocols suitable for communications between the spacecraft and ground stations is designed and simulated with OPNET Modeler, which indicates that the QoS guarantee of wireless communication links can be achieved. At last, a method for establishing a QoS guarantee simulation platform in OPNET is proposed based on the network topology of space-ground internetwork and the network analysis. A detailed analysis of the QoS guarantee performance of a plurality of services is presented after simulating the operations of space missions on the platform.