Research On Energy-Based Edge Cache Strategy In Mobile Edge Networks

With the growth of Internet business and the popularity of smart mobile terminals,such as wearable devices,smart phones,virtual reality,and augmented reality,mobile data traffic is experiencing explosive growth.The explosive demand for mobile Internet traffic has brought great pressure and challenge to mobile communication networks.Increasing the deployment density of the base station and improving the frequency reuse efficiency can alleviate the problem of traffic surge to some extent,but it cannot solve the contradiction between the limited backhaul link capacity and the continuously surging data traffic.In order to provide users mobile network services with higher quality of experience,deploying cache in the network is an effective method to reduce network delay,system energy consumption and edundant content transmission,and improve content distribution efficiency.By caching popular files users frequently requested at the edge of the network,users do not need to obtain them from the core network through the backhaul link,so it can reduce the pressure on the backhaul link,the system energy consumption and improve network performance.Firstly,based on caching in MBS and SBS,this paper introduces D2 D layer cache to form a three-layer cache architecture.Moreover,the modeling analysis of each component of the three-tier architecture is carried out.In order to solve the problem of insufficient consideration of content size in the existing research on cache strategy,the cache strategy studied in this paper considers the influence of content size.The traditional Zipf distribution based on the popularity is optimized by weighting size of the content,and it is applied to the three-tier cache architecture.Besides,this paper explores the influence of a certain range of weight factors on system energy consumption.The simulation results show that the introduction of D2 D and the combination of new popularity based on content size weighting can reduce the system energy consumption compared with the caching strategy of no cache and using the popularity of Zipf distribution to cache popular content.Then based on the three-tier cache architecture formed by MBS,SBS and D2 D,this paper adopts the idea of partial cache.When formulating the cache strategy,not only the content with high popularity but also the content with low popularity are considered,so as to avoid the large backhaul rate and system energy consumption when users request the content with low popularity.Based on this cache strategy and the three-tier cache architecture,the backhaul rate and energy consumption of the system are analyzed theoretically,and the specific expressions and derivations of backhaul rate and energy consumption of the system are respectively given.in addition,the problem of minimum energy consumption of the system is transformed into the optimization problem,which is to find the appropriate cache proportion for each file to minimize the total energy consumption.Simulation results show that the introduction of D2 D and the cache strategy based on the idea of partial cache can reduce the system energy consumption.