Message Forwarding Strategy Research Based On Community In Opportunistic Network

Opportunistic network is a new Ad Hoc network which utilize communication opportunities from movement of nodes to transfer messages without a complete link between the source and destination node.The message propagation depends on a "store-carry-forward" fashion.Opportunistic network has been widely used in these areas of handheld devices network,vehicle network and intelligent transportation,which has greatly improved people's lives.Nodes in opportunistic network are devices which has the function of wireless communication,which are mostly carried by human.Nodes move together and form the community structure.Existing community division algorithms divide the network into different communities in the case of access to global information of network,and its computation amount and time cost is larger.However,due to the energy,computing resources and storage resources of nodes are limited,it is unable to detecting the network state information for long time for nodes and not suitable for running complex calculation.Therefore,existing community division algorithm does not apply to opportunistic network.In order to obtain a community division algorithm that can be suitable for opportunistic networks,this paper proposed a community division algorithm based on the evolution of friendships.First,it defined the friendship metric that described the strength of the relationships between nodes.Then,utilizing this metric and the encounter history of nodes,the nodes in the networks were divided into different friendship communities.Due to the frequent movement of nodes in opportunistic network,the exhaustion of nodes' energy or the communication failure of nodes,it is almost impossible to exist a complete end-to-end communication links and the forward ability of network would have a great influence.In order to obtain messages forwarding algorithm that can be suitable for opportunistic network,this paper proposed a message Forwarding Algorithm Based on relationships(FBFA,Friendship Based Forwarding Algorithm).FBFA designs the forwarding table for each node and handles the problem of the constantly changing friendships between nodes on the foundation of friendship community division algorithm.The experiments results under different sets of data show that routing overhead has reduced effectively and the transmission rate still keeps a high value by using friendships to divide communities,and comparing with three mainstream message forwarding algorithm,the FBFA can effectively improve the efficiency of network to the forwarding of a message.