Delay-Tolerant Network Routing Based On Probability Of Relay And Social Analysis

The DTN(Delay Tolerant Networks)is a new-style network model that is distinct from traditional wireless networks.There may be not stable and continuous end-to-end connectivity,thus DTN transmits messages based on the “carry-store-forward” transmission characteristic in which messages are stored in the nodes and opportunistically transmitted by node mobility.Therefore,DTN is also a class of opportunistic networks.Present researchs of DTN routings mainly put emphasis on extraction of social characteristics and routing strategies of messages among nodes.As a result,there are few researchs of communication qualities of nodes with weakness of social relation and isolate nodes.Firstly this thesis studied a model of transmission probability is designed by the way of combining with analysis of historical information for nodes' encounters and social relationship,and the thesis specifies its importance in DTN routings.The analysis of historical information is to forecast short-run movement characteristic by independent probability computation and probability information exchanges with each other when nodes encounter,and the analysis of social relation is to forecast long-run movement law by the degree of intimacy among nodes formed in long-run movement.Finally,Delay-Tolerant Network Routing Based on Prabability of Relay and Social Analysis(RPRSA)is proposed,and RPRSA is simulated through ONE platform.The simulation results showed that RPRSA can guarantee quality of messages' transmission among nodes with weakness of social relation and isolate nodes,and average success ratio of transmission in the network.The thesis indicated the deficiency of RPRSA on average transmission ratio,and an improved RPRSA was proposed after analyzing the routing algorithm of Spray and Focus(SaF).The simulation results showed that improved RPRSA can enhance average success ratio of transmission in the network,however,can not obviously reduce the number of source nodes that communication failed.