Research Of Routing Algorithm For Space Delay Tolerant Networks

With the rapid development of the world’s aerospace industry and space networks, the establishment of a Space-Air-Ground interconnection network is becoming an important research focus. Spatial network is characterized by network topology, long information delay and asymmetric transmission ratio, which is different from TCP/IP networks. Apparently, traditional Internet cannot be well suited in the spatial environment.DTN(Delay/Disruption Tolerant Networks, DTN) is derived from Interplanetary Internet architecture. It uses the idea of ‘overlay’ and storage-carry-forward to realize reliable data transmission. In view of the characteristics of space communication network, the space DTN routing issues are studied in this thesis. The primary work and contributions are as follows:Firstly, the different characteristics of the space and terrestrial networks are introduced and the applicability of DTN in spatial environment is proposed. Then some of the classic treatise on DTN routing method is classified, such as flooding-based routing, knowledge-based routing and contact graph routing. The relevant simulation tools STK and ONE are described and some routing performance indexes are presented.Secondly, this thesis proposes a routing called UPHR(Utility and Probabilistic Hybrid Routing, UPHR), which is based on nodes’ utility and probability. UPHR utilizes the concept of nodes’ similarity and betweenness centrality to apply to the spatial network nodes, and defines the nodes’ redundancy to make nodes’ utility value more explicit discrimination. Taking advantage of the improved ProPHET algorithm and combined with partial regularity spatial node movement, the next node selection accuracy is enhanced. The simulation result shows that this proposed routing has better performance in delay and delivery than ProPHET.Finally, space DTN secure routing is studied in the thesis. Because of spatial network’s open feature, it is more vulnerable to theft, tampering. The research uses cryptography scheme to design the routing ICSR(Identity-based Cryptography Security Routing, ICSR). The result confirms the effectiveness and feasibility in DTN security.