Efficient Cache Strategy In Ultra Dense Cellular Networks

Mobile data traffic impacts the current communication link system as a tsunami.In order to accommodate and manage these mobile data better,we proposes a distributed cache strategy based on the ultra dense network proposed in 5G,which combines the content of user request and the mobile information of the user.In the case of limited backhaul link,the users can get the requested data files more by caching nodes,relieving the return link pressure and improving the energy efficiency of the system.The main contents of this paper are as follows:First,a caching model of heterogeneous super dense network is proposed.Then we conclude the energy efficiency function of the system.By assigning the cache node to the small base station and giving the caching algorithm of user content to alleviate the pressure of the backhaul link of the communication system,the efficiency of the whole communication system is optimized.Combining the popularity and the size of the data files,we calculate the cost of any file.Finally,with the GD-CF algorithm,the solution of the small base station caching strategy is decided,reducing the service rate of the micro station.Meanwhile the energy efficiency of the system is optimized.Secondly,aiming at the mobile behavior of users in ultra dense wireless networks,an improved distributed caching strategy is proposed.With analyzing the change probability and users in different locations,we predict the area that the user may enter in the future,and the data that requested by the user is stored in different small base station caching spaces respectively.By establishing the Markov chain model,the distributed cache problem is transformed to minimizing the probability that user's request information is oriented to the macro station,and then the target function is transformed into the maximum the value of users' path weight by Hoeffding's Inequality for Markov Chains.Finally,the problem is decoupled into the N sub-strategy to obtain the optimal distributed cache.Strategy.Finally,the result of the experimental simulation about the caching strategy that proposed in the upper content is shown.By comparing the cache hit rate,the cache space and the number of user equipment and the system energy efficiency,the feasibility and effectiveness of the proposed strategy are verified.