Design Of Information Coverage Maximization And Probability Caching Algorithm Based On RSU In 2-D Environment

With the development of vehicle networks,the transmission of information inter-vehicle has become more and more important.The Vehicular Ad-Hoc Network(VANET)is a vital part of the intelligent transportation system and an important extension of the Internet of Things in the transportation field.For the traffic safety data,it requires real-time communication and relies on the vehicle network,and the optimization of the vehicle ad hoc network depends largely on the coverage of the information.In the existing studies,they mainly carries out in 1-D environment,or concentrates on the communication of vehicle-to-vehicle to enhance the coverage for a given road network.Therefore,there is still lack of clear understanding on using road infrastructure now,improving information coverage in the urban areas.And existing the decisions of vehicle ad hoc network cache rarely considers cache coordination between infrastructures,which tends to cause the same content cached by the adjacent nodes.What's more,the cause of limited channel bandwidth and frequent network topology changes is that vehicle requests are difficult to respond in time so that the global network cache efficiency is degraded.Therefore,The main research contents of this paper are as follows:1)This paper introduces an infrastructure-based information coverage maximization algorithm(ICMA),and builds a model that based on traffic density in this region and delay constraints of the application to implement message maximization coverage algorithm,takes into the influence of different parameters on information coverage,and carries out a large number of simulations,for the broadcast storm problem,using the time barrier mechanism data propagation scheme(TBEP)to reduce the delay and help improve the information coverage,this paper combines ICMA algorithm and TBEP,the algorithm selects different delay constraints in TBEP to obtain two different deployment sets at ICMA.The simulation results show that the combined algorithm outperforms the existing algorithms in terms of information coverage and information propagation speed in the two deployments.2)From the perspective of VANET,the infrastructure cache plays an important role in the efficient dissemination of content between vehicles and between RSUs,so consider the preference of the user-requested content at the RSU to match the size of the cache interval.Probabilistic Cache Algorithm based on user preference(PCS-UP)is proposed.The request hop count with high content request rate is converted into weighting coefficient to calculate the more accurate request user preference.Then the cache probability of the packet iscalculated by the joint buffer interval.The uniform buffering of different data is completed.The simulation results show that the proposed algorithm effectively improves the cache hit rate of the system,reduces the average response hop count,and reduces the channel access delay.