Research On Two Tier Architecture Based On UAV Assisted VANET

In recent years,VANET(Vehicular Ad-hoc Network)is in full swing,which makes VANET a recognized reliable network for communication between vehicles.With the rapid increase in the number of vehicles and increased road traffic pressure,VANET will provide greater advantages in the construction of smart transportation in the future.However,the high mobility of vehicles and the variability of network topology have led to the efficient transmission of data packets in VANET as one of the important challenges for the construction of smart transportation.In fact,when the traditional RSU(Road Side Unit)or bus alone is used to make up for the problem of poor upper network coverage,the RSU cannot be adjusted in real time according to the dynamic traffic flow due to its high cost and immovability;And buses often cause uneven distribution due to frequent changes in traffic volume,which in turn causes data transmission delays or disconnections between vehicles that rely on their networking.In order to overcome these difficulties,this paper proposes to use the characteristics of UAV’s(Unmanned Aerial Vehicle)strong flexibility and easy deployment to assist in the transmission of information between ground vehicles,and combined with the characteristics of wide transmission range and stable line of the bus to jointly ensure the stability of the collection and transmission of data packets.Based on this,this article proposes a two-tier architecture based on UAV-assisted VANET.The specific research content is as follows:Firstly,both the drone and the vehicle maintain a position information table for other vehicles to communicate,and through UAV use timing,transmission radius,minimum time to transmit data packets with ground vehicles and other factors established the constraints of the UAV.During the movement of the drone,divide the drone’s activity range into different areas,calculate the probability of the vehicle reaching different areas,and select the area with the largest probability value as the best location for the drone to collect data packets.Secondly,in the study of the energy consumption model of the UAV,two situations are considered: one is the energy consumed when the UAV communicates with the ground vehicle,and the other is the energy consumed when the UAV moves at high altitude.Through comparison,it is found that mobile energy consumption has a greater impact on the total energy consumption of UAVs.Therefore,the Pareto optimal method is selected to jointly optimize the two.The data packet routing stage adopts the improved AODV protocol,which selects the path with the least link cost according to the remaining energy value of the vehicle node to realize the aggregation and forwarding of data,reducing the path search time.Finally,the simulation experiment of this paper is designed,and the two-tier architecture proposed in this paper is evaluated by using the traffic simulation software SUMO and the network layer simulation software OMNET++ in parallel.The data packet transmission rate,average end-to-end delay,and average number of hops were analyzed under the conditions of different numbers of drones and different vehicle density independent variables.The results show that the architecture of this article is better than traditional in terms of performance vehicles communicating only based on the AODV protocol,the GYTAR protocol,and the UVAR protocol.