Cooperative Caching Mechanism Based On Edge Cache Technology

With the development of next-generation communication technology,the intelligent terminals accessing the network are exploding and many high-bandwidth and low-latency mobile applications are emerging,making it difficult to be supported by the centralized mobile network architecture alone.To cope with the massive amount of endpoint-generated data traffic,edge cache technology has emerged as a potential solution for next-generation communication networks.In addition,the limited cache space and computing resources of a edge base station can hardly make users satisfied.In response to this problem,considering the joint caching of multiple edge base stations can fully utilize the edge storage resources.However,collaborative caching can also add to the backhaul load in the collaborative network.Therefore,the thesis investigates the cooperative caching mechanism in edge computing environment,and proposes active cache placement strategy and adaptive cache replacement strategy,respectively.In particular,the following tasks have been completed:1.Under the MEC collaborative caching architecture,the edge collaborative cache placement problem is modeled as a multi-constrained global cost-optimal problem for the high cache redundancy problem caused by edge base stations caching only the hot content of this base station,considering different user preference differences,file sizes,and the average request traffic of edge servers.The cache placement problem combines both the cache latency cost incurred by caching content and the system energy cost.Then,a costoptimized cooperative cache placement strategy based on a greedy algorithm for user preferences(CEC-GRA)is proposed based on the problem.Finally,through simulation experiments,it is verified that the proposed cache placement strategy can effectively improve cache hit rate,reduce edge cache redundancy,and decrease average content delivery latency and average system energy cost.2.As users’ content request preferences change dynamically over time,which leading to degradation of collaborative caching performance.Based on Work 1,the adaptive edge cooperative cache replacement strategy(AECCR)is proposed.The strategy studies and analyzes the user request patterns in different time slots under micro-base stations in MEC caching networks,constructs a dynamic user request model based on Poisson’s scattered grain noise process,and defines a cooperative caching community.The strategy also integrates the replacement content with the reacquisition probability of the content to be cached on the micro-base station,combined with the co-caching cost of the content to be cached for the caching community.The simulation results show that the AECCR strategy has improved in terms of cache hit rate and average content delivery delay compared to other compared strategies.The research work shows that the CEC-GRA strategy and the AECCR strategy can improve the edge cache performance and reduce the co-cache cost compared to other traditional edge cache strategies.