Design Of Efficient Data Distribution Algorithm In Vehicular Ad Hoc Network

Vehicular ad-hoc Networks(VANETs)is a research hotspot of Intelligent Transportation Systems(ITS),which is used in the Transportation road of traditional mobile self-organizing Networks.Due to the high-speed movement of vehicles,the topology of VANETs network is fast and the path life is short,which can lead to high mobility of short distance communication.In addition,due to the limited coverage of roadside units,the loss of wireless channel data distribution will lead to a severe test for the data distribution of VANETs.In VANETs,vehicles and vehicles can be forwarded together through collaborative data,thereby reducing the load on the RSU roadside Unit(RSU,Road Side Unit).Accordingly,design effective RSU data distribution algorithm,therefore,to design effective RSU distribution algorithm,thus improve the efficiency of vehicle and roadside infrastructure data distribution is a problem worthy of further research hotspot.This paper focuses on how to improve the efficiency of VANETs,comprehensively consider various factors,and the following data distribution mechanism is proposed by adopting the relay collaboration technology:(1)this paper proposes a RSU for data distribution algorithms VAIC(V2V and I2V currency)algorithm.The adoption of multicast data distribution,RSU vehicles can accept within its coverage to the RSU multicast information.When the RSU multicast data entry cannot meet the demand of the vehicle,the data transmission between the vehicle and the vehicle is transmitted through the coordinated dispatching of the RSU.The process of this algorithm includes two stages:in the first stage,the vehicle request within range of RSU comprehensive consideration,multicast request data,the second phase,RSU scheduling between appropriate vehicles for forwarding,to comprehensively consider the data distribution of two stages,select the optimal way of data distribution.Through the simulation results show that the presented algorithm and the traditional algorithm of First Come First service(FCFS,First last Come First Served)and vehicle request data entries up to First send algorithm(MRF,Most Requested First),can effectively improve the vehicle request is service.(2)this paper proposes a relay selection algorithm based on doppler frequency shift,due to VANETs topology changes.quickly,link frequent disconnection between vehicle and roadside units,located in the RSU coverage beyond the range of the vehicle due to the poor quality of channel can’t directly communicate with roadside unit,data distribution efficiency is reduced.The algorithm considers the doppler frequency shift,the size of the requested information,and vehicle channel gain,by cooperating the judgement of relay,choose the best relay vehicle,to implement the communication between vehicles and vehicle data forwarding.With direct communication algorithm and compared based on vehicle distance(closest)algorithm,the experimental results show that the presented algorithm is effective in reducing the vehicle request service time,increase the proportion of the vehicle request is service,effectively improve the efficiency of data distribution.