Research On High Performance Routing In Space Information Networks

With the rapid development of satellite communication technology, technologies ofspace communication especially for satellite communication have made a great progressin communication quality and communication scale, those have brought greatconvenience for our jobs and lives. Space information network (SIN) is the furtherdevelopment of satellite network, and it can associate spacecrafts, ground networks withsatellite networks. SIN can provide global coverage, guarantee of high transmission rateand bandwidth, and it also can support flexible and large-scale network structure.Satellite network is acted as the backbone network of SIN, so it is required to providehigh reliability, high quality access service and QoS assurance for ground users. But thesatellite network is composed by single layer’s LEO, MEO or GEO satelliteconstellation is difficult to satisfy the above conditions. Therefore, we must combine theadvantage of different orbit layers’ satellites constellation to structure the backbonesatellite networks of SIN. Routing technology of SIN is the key technology for SIN,especially for its satellite backbone networks. There are some research have made forwireless Ad hoc network and wireless Mesh network (WMN) in the word at present,those research can be used as a source of references for the routing research of SIN.Because of SIN’s own characteristics, its routing protocol is difficult to make full use ofthe features of wireless Ad hoc network and WMN to help it to improve theperformance of its routing, so it is required to according to the features of SIN to designthe routing protocol of it. Thus it has important significance in the study of routingprotocol of SIN. Some high performance routing protocols of SIN are studied throughtheoretical analysis and simulations in this dissertation, the main contributions of it areas follows:1. The construction of hierarchical network of SIN is studied, and thecharacteristics of hierarchical topological structure are analyzed, and advantages of itare displayed in this chapter. Combining with characteristics of different orbits ofsatellite constellation, a model of two-layered satellite backbone networks based on thehierarchical SIN is proposed. Finally, the orbits, geometric structure, network topologicstructure and constellation design of two-layered satellite backbone network are furtherstudied. The necessity to develop routing protocol of satellite backbone networks of SINis pointed, and the design method of routing protocol is expatiated.2. A special and effective distributed on-demand routing protocol in two-layeredsatellite backbone networks of SIN is proposed. Independent computing of shortest path for each satellite link is taken in this protocol, so it can response quickly for currentnetwork status, and keep the minimization of end-to-end delay, delay jitter and signalingoverhead. In contrast to the routing protocol of single-layered networks and classicalrouting protocol in double-layered networks, simulation studies further record andconfirm the positive characteristics of this protocol on the mean end-to-end delay, themean delay jitter, the links’ congestion and satellite failure, etc.3. A two-layered composed of low-earth orbit and medium-earth orbit satellitebackbone network of SIN is presented, and a novel self-adapting routing protocol isdeveloped. This scheme aims to adopt self-adapting routing algorithm to supportdifferent traffic classes. Meanwhile, the path discovery processing is invokedindependently for each individual origin/destination pair. Simulation results areprovided to evaluate the performance of the new scheme in terms of end-to-end delay,normalized data throughout, delay jitter and delivery ratio.4. According to the features in satellite backbone network of SIN, a trustedevaluation model of satellite nodes is given and a trusted on-demand routing protocol isproposed. Based on this model, the trustworthiness of direct trust degree and indirecttrust degree of network’s nodes can be obtained from it. Then the trusted routes ofsatellite nodes can be computed according to the trustworthiness of network’s nodes.This routing algorithm can select a trusted route to transport data based on thetrustworthiness of network’s nodes. Compared with the classical on-demand satelliterouting, simulation results show that it can effectively resist attacks and improve thereliability robustness and security in satellite backbone networks of SIN.