Multilinear Closeness Routing Algorithms Based On Meeting Probability In Low Cache Delay Tolerant Networks

The delay tolerance network is mainly deployed in extreme environments.Each node in the network often moves,and sometimes it is limited by the node's own energy and cache space.It cannot establish an end to end protocol like TCP/IP.There is a low message delivery ratio and a high average latency in delay tolerance network.Based on the classical algorithm of replication,forwarding and hybrid strategy,the improvement of mutual communication in the delay tolerance network is limited.This paper proposes a multilinear intimacy optimization algorithm based on the probability of encounter.It can improve the message delivery ratio of low cache conditions,reduce network overhead and the average latency.It meets the application scenarios of delay tolerance network in wildlife monitoring,space communication and disaster emergency.This paper first introduces the definition of the delay tolerance network.Then the origin and characteristics of the delay tolerance network is also introduced.At the same time,the classical algorithm is elaborated,and the research status at domestic and abroad in this field is briefly narrated.Then the description of the experimental simulation environment ONE platform is given account of.And the definitions of message delivery ratio,network overhead,average latency,and average hop count are explained,which facilitates to compare the advantages and disadvantages of the improved algorithm.In order to improve the message delivery ratio of the delay network under low cache conditions,this paper proposes an improved SprayAnd Wait algorithm based on multilinear intimacy index and replication strategy.In the spray stage,the utility model predicts the number of message copy by the probability of encounter between each nodes.In the wait phase,it is decided whether to copy the message to the other node by comparing the multilinear intimacy index.The above improvement measures can significantly improve the delivery ratio in the delay tolerance of low cache.In order to further improve the delivery ratio,it is necessary to reduce the overhead ratio and solve the problem of message redundancy in the case of low cache.This paper first saves the storage space through the message ACK con:firmation mechanism.Reduce network overhead ratio by forwarding strategy and replication strategy switching mechanisms.The message is arranged in descending order by the encounter probability index.And when the node has a new message generated without storage space,the message with low encounter probability index is deleted.In the process of message forwarding,the encounter probability index is also used.So that the message with high delivery probability is transmitted first,and overhead ratio are reduced while ensuring the delivery ratio.In terms of experimental simulation,this paper compares the improved algorithm with the classic algorithms Epiidemic,SprayAndWait,and Prophet.By changing the simulation duration,the size of the cache space,and the message life period,we can study the actual performance of the improved algorithm in different scenarios.It can be seen from the experimental simulation results that the improved algorithm can significantly improve delivery ratio and reduce network overhead ratio in the delay tolerance network of low cache.