Cache Placement And Routing Strategies In Mobile Network

With the rapid development of wireless communication network,users' demand for hd video service is increasing day by day.However,with the continuous improvement of video quality,the demand for the transmission rate and efficiency in wireless network is always increasing,and the bandwidth resources are also limited.In order to solve the above problems,content caching near the users' side has become a feasible and effective method.Therefore,how to cache contents directly affects the communication cost and users' experience.We try to solve this problem in wireless communication network.This paper mainly studies how to optimize the cache placement and routing strategy to reduce the cost of operators and reduce the communication latency to improve the user experience.The main work of this paper is as follows:1.We build a model to describe cache placement and routing in wireless communication network,and divide it into static and dynamic in terms of time.Based on the data of real files being clicked,this paper studies the popularity of files in wireless communication network.2.We set up system model based on real content delivery network and present a joint optimization of cache placement and routing strategies for minimizing both communication of operators and delay of users.We propose the alternating optimization algorithm and the alternating direction multiplier method for solving this problem respectively.With the commonly used buffer placement and routing strategies in reality,we confirm that our proposed algorithm is effective,reliability and robustness.3.We generalize the prediction of content popularity to the multi-armed bandit(MAB)problem and use Upper Confidence Bound(UCB)and Thompson Sampling for prediction respectively.Then,We optimize the content placement and routing strategies,considering the joint cost of cache placement and request for contents.Based on the estimated content popularity,we use alternating direction method of multipliers(ADMM)and greedy algorithm to solve the optimization for minimization of total cost over working time of network.Simulation results shows that the two proposed algorithms both have better performance than classic caching update strategies,LRU and LFU.In summary,this paper studies the content placement and routing in wireless communication networks under both known and unknown situations of popularity,and proposes algorithms to solve problems in wireless communication networks with the aim of reducing communication cost and delay.The simulation results also show that through the reasonable cache file and routing arrangement,the cache hit ratio can be effectively increased to achieve the ultimate goal of improving user experience and reducing network cost.