Research On Mobile Aware Caching Strategy In Vehicular Edge Network

The existing network architecture cannot meet the requirements of 5G lower latency task.Mobile edge computing is proposed and considered as a feasible technology to satisfy the latency requirements of networks.It sinks the cloud computing environment to the edge side closer to the user to reduce network operation and service latency.Therefore,applying mobile edge technology to the Internet of Vehicles can improve the service quality of users.At the same time,effective data caching helps to reduce the retransmission of duplicate data.Therefore,the introduction of caching strategies in the Internet of Vehicles can reduce transmission costs and further improve network performance.However,the storage space of vehicles is limited,how to design an optimal cache content placement strategy suitable for vehicle union edge network and reduce the latency of vehicle cache update has become an urgent problem to be solved.This paper focuses on the mobile sensing cache in the vehicle union edge network environment.The main research work of this paper is as follows:(1)A content placement strategy based on mobile perception to minimize energy consumption is researched.In this scheme,the running vehicles are divided into typical vehicles and other vehicles.Typical vehicles refer to the vehicles that need content update,and other vehicles refer to the neighbor vehicles within the communication range of the requesting vehicle.Considering the mobility of the vehicle,firstly,the temporal and spatial characteristics of the vehicle are modeled;Then,an LU(Last Updated)algorithm is proposed to select the vehicles that need cache update;Then an optimization problem is formulated to minimize the average energy consumption of the base station by optimizing the cache content placement of the vehicle;Finally,it is proved that the problem can be equivalent to the maximization problem of unimodal submodular function with matroid constraints,which is solved by greedy algorithm.The results show that the scheme can achieve near optimal performance under low complexity.(2)A cache content update algorithm based on vehicle clustering is researched.Firstly,calculate the angle between the vehicles according to the positions of the vehicles at different times,and initialize the vehicle cluster based on the moving direction;Secondly,the Euclidean distance between vehicles is used to describe the sample difference,and clustering is carried out according to the Euclidean distance between vehicles and the content type of cache;Then,the priority of all nodes in the cluster is evaluated,and the cluster head is selected according to the sorting results;Finally,based on the results of clustering and cluster head selection,the average latency of vehicle content transmission is calculated.The results show that compared with other schemes,this scheme can greatly reduce the repeated transmission of the same data and improve the quality of service.