Improvement And Application Of Prophet Routing In Delay Tolerant Network

In recent years,with the advent of special network scenarios such as interstellar networks that have long transmission delay and easily-broken communication links,kevin Fall et al proposed a new type of network architecture(delay tolerant network,DTN)in 2003.The difference with the traditional TCP / IP network is that DTN is a kind of mobile ad hoc network with intermittent connection,easy interruption and high bit error rate.In most cases,there is no end-to-end transmission path and stable infrastructure.With the DTN network being payed more and more attention,DTN is more and more widely used in real life too.The main applica tions of DTN include wildlife tracking and habitat detection network,rural communication network,interstellar network and laser communication.The goal of DTN is to achieve reliable delivery of messages in a degraded network environment with long link delays and frequent link disconnections.Due to the particularity of DTN network environment,the traditional TCP / IP protocol applied to the Internet can not meet the communication requirements of the network.In order to transmit messages more efficiently in this environment,DTN adds a new protocol layer,namely the bundle layer,based on the original TCP / IP protocol.By using store-and-forward message management policies at the bundle layer,nodes can still successfully deliver messages in harsh network environments.The routing and buffer management of DTN network are mainly studied and summarized,and we simulates the routing and buffer management strategies proposed in this paper on ONE simulation platform.The main research and innovation of this paper are as follows:1.The characteristics,architecture and application scenarios of DTN networks are carefully studied.The design ideas of DTN routing and the classification of routes are analyzed in detail.The implementation principles,advantages and disadvantages of several typical routing algorithms in DTN are studied too.At the same time,the DTN congestion control algorithm is reseached in depth.2.Based on the original prophet routing,considering the effect of node buffer size on message transmission,Prophet-FBSR routing based on node buffer residuals is given.ONE simulation tool is used to simulate the improved prophet routing.From the simulation results,it can be seen that the improved Prophet routing strategy enhances the three network performance indexes such as message delivery rate,network overhead rate and message average delay.3.Due to the particularity of DTN network and the limitation of node buffer size,the network congestion easily occurs in the transmission of messages,which leads to the reduction of the transmission rate of messages in the entire network.So effective cache management strategy is essential.Based on the analysis of the traditional buffer management algorithm,PFBM(Prophet-FBSR Based Buffer Management)is proposed.That is to discard the messages with smaller value survive calculated by PFBM when congestion occurs.Through simulation comparison,the hybrid buffer management strategy presented in this paper has obvious improvement on network performance indexes compared with other management strategies.