Research On DTN Routing Algorithm Based On Network Coding

The concept of delay tolerant network(DTN)was proposed by Kevin Fall at the International Conference in 2003.As a new type of network architecture,Delay Tolerant Network has no continuous or contemporaneous connections among wireless nodes and without infrastructure support.It is mainly used for wireless communication in the extreme environment,including mobile ad hoc network,vehicle network,space communication network,etc.Due to the characteristics of Delay Tolerant Networks,the design of efficient routing algorithm can improve network connectivity.Moreover,the DTN routing algorithm based on network coding has become one of the hotspots.This paper introduces the network architecture,characteristics and applications of Delay Tolerant Network,and expounds the basic principles of network coding and DTN routing technology in detail.I have studied the two existing algorithms:Dynamic Segmented Network Coding for Reliable Data Dissemination in Delay Tolerant Networks(DSNC)and A Clustering Routing Method Based On Semi—MarkoV Process and Path—Finding Strategy in DTN(CRSMP),and find out the shortcomings of the algorithms.According to the existing problems,we puts forward the corresponding improvement scheme.The specific work and main achievements include the following two aspects:(1)In order to solve the problems of data redundancy and low delivery ratio in DSNC algorithm,this chapter proposed a routing algorithm for DTN based on dynamic segmented network coding and transmission capacity control(NC-TCC).The AONT matrix is used to encode the data at the source node of the network to avoid redundant coding.At the intermediate nodes,the transfer capacity of opportunistic connection is calculated according to the mobile model of nodes.While the encoded packets does not exceed the transfer capacity and the data with higher priority are selected for random coding.This method is easy to achieve the successful transmission of data.Simulation results show that the algorithm can effectively reduce the data redundancy and improve the efficiency of data transmission.(2)In order to solve the problem of large storage overhead and long transmission delay in CRSMP,A Clustering Routing Method based on the Main Path Coding(CRMPC)is proposed.CRMPC uses a linked list with length restrictions for the storage scheme to reduce the storage cost of the later period.In the stage of clustering,a set of clusters with more nodes is constructed by reducing the average similarity of sets.In the route discovery phase,considering the different effects of the path forwarding probability and the waiting time,we find the next hop with the largest ratio of the forwarding probability and the root value of waiting time.This strategy can not only guarantee the probability of path transmission but also limit the transmission delay.Combined with the clustering results,the search strategy is used to generate the corresponding multicast paths.And the network coding transmission scheme is adopted in the main path.The simulation results show that the CRMPC algorithm has more advantages over the CRSMP algorithm in terms of network overhead and transmission delay.