Research On Campus DTN Social Routing Algorithm

Delay-Tolerant Network(DTN)is a sparse dynamic wireless network.In DTN,The mobile node transmits data through the opportunity of the node in the mode of ad hoc network.DTN allows people to communicate without the network infrastructure and it is widely used in the field network,vehicle network,wildlife tracking network,etc.At present,the main challenge of DTN communication is routing.It is a difficult problem to transmit data from the source node to the destination node through intermittent connections in the mobile environment and is also a hot research topic in DTN.The mobile phones,tablet PCs and other smart portable devices can be used as a mobile node in the network,and give the same social properties as the people.Because the movement of these nodes is non-random,it is proposed that the routing algorithm can significantly improve the routing efficiency by using some social attributes of nodes.Considering campus DTN is a typical social network,the paper proposes routing strategies that have obvious routing effect on campus environment according to the motion characteristics of people in campus:a routing algorithm based on prediction and a routing algorithm based on cluster.The main research content of this paper is as follows:(1)Routing algorithm based on prediction of historical trajectory(CNPHT).When the routing algorithm such as CS-DTN at this stage predicts the node movement,it often needs to know node position information.However CNPHT predicts the probability ofa node to reach the designated area after the prediction of the forward delay by using the historical trajectory when the destination node position information is unknown,and it avoid the situation that message can not forward out because of too high Simbet value when using Simbet algorithm.And it also analyzes the possibility of the destination node in each region after the prediction of the forward delay and solves the problem that the message delivery is not successful due to the moving of the destination node;A node that resides in a static state for a long time is not as a reference node for forwarding information,which may reduce energy consumption and waste of resources caused by unnecessary computation and information exchange;"High mobility nodes”frequently moving in different areas complete message passing task to further improve the delivery success rate of message forwarding.(2)A DTN routing algorithm based on cluster.As for routing algorithm based on cluster,the paper proposes a routing protocol based on Relay Cluster Prediction Model(SRP-RCSM)according to the motion characteristics of nodes such as moving in groups.Existing DTN routing algorithm such as Smart aims to reflect connections between nodes,SRP-RCSM takes the close relationship between clusters into account to adapt to the characteristics of the campus DTN.It forwards message to the cluster with greater probability of meeting the target cluster according to the conditional encounter probability to make message sent to target cluster as quick as possible and it improve delivery ratio and transmission speed.In this paper,the opportunistic network platform ONE simulation platform is used to test the CNPHT and SRP-RCSM.Experimental simulation results show that,compared with the traditional algorithm such as Simbet,Prophet,etc,CNPHT and SRP-RCSM have better performance.