Research On Improved Routing Algorithm And Cache Management Mechanism Based On Node Quality In Tolerant Network

DTN(Delay Tolerant Networks)is a new type of mobile ad hoc network.It is a wireless self-organization of inter-node communication through random movement of nodes in the network when there is an unstable path between the source node and the destination node.The internet.Because there is always a movement between nodes in the network,there are characteristics that the node links are frequently disconnected and the network topology changes,so that the traditional network protocol cannot operate normally in the late-latency network.Based on this situation,the nodes in the delay network usually use the "storage-carry-forward" method to forward the message.Because the nodes in the network need to carry messages during the movement,there is almost no complete DTN network.The end-to-end link,and the existing wireless network-based routing message method and cache management mechanism can not be used in DTN,so the study of effective routing message method and cache management mechanism has become DTN network research.Important question.Based on the existing routing message method and cache management mechanism in DTN,this paper studies the SW(Spray And Wait,SW)algorithm in DTN and the existing cache management mechanism:(1)Based on the existing DTN,the message delivery rate is not high,the transmission delay is high,and the network overhead is large.After studying the SW algorithm,a SW algorithm based on node quality is proposed for the shortcoming of SW algorithm.Improved algorithm SWBNQ(Spray And Wait Based Node Quality).Firstly,according to the historical encounters between the nodes and the effective encounter time,the historical intimacy between the nodes is defined,and the relay node of the message is selected according to the historical intimacy between the nodes;then the message is successfully forwarded according to the node at the most recent time.The number of nodes is compared with the number of nodes encountered by the node to define the message forwarding capability of the node(ie,the quality of the node itself).When the node.distributes the message replica to the relay node,the node forwards the relay node according to the message forwarding capability of the node.The distribution of the message copy is performed to ensure the matching of the number of copies of the message and the message forwarding capability of the node.The SWBNQ algorithm improves the delivery rate of messages in the DTN network,and reduces the delivery delay of messages and the number of path hops that messages pass.(2)Based on the existing network congestion and low message delivery rate in the existing DTN network,a message quality based cache management algorithm MQBCM(Message Quality Based Cache Management)is proposed.The algorithm defines the message quality of each message through the lifetime of the message in the DTN network and the number of times the message is forwarded.According to the quality of the defined message,when the network congestion occurs,the message with low quality is preferentially discarded.High-quality messages to improve the delivery rate of messages in the DTN network and reduce the delay of message delivery.(3)Using the DTN simulation software ONE(Opportunistic Network Environment simulator)platform for simulation experiments,the above-mentioned SWBNQ algorithm and MQBCM cache management mechanism algorithm are implemented through the ONE platform,and multiple sets of simulation experiments are compared with other algorithms.The comparison results verify the superiority of the above algorithm.