Research And Implementation On Efficient Proactive Caching Of Femtocell Via User's Moblity And Popularity

With the development of the Internet and the popularity of smartphones,more and more people use the mobile terminal access to the Internet,the traffic load of Macrocell is also growing.Deploying a large number of Femtocell can alleviate the traffic load pressure of Macrocell effectively.The Femtocell can reduce the network transmission delay.However,users are more and more demanding on the stability of mobile traffic,network response speed and network latency,Therefore,scholars have proposed the distributed cache technology that all nodes are connected with each other and work together.As the handover of user's communication became more and more frequent,we focus on the distributed pre-caching via the user's mobility,and on this basis,we study the pre-caching algorithm based on the popularity and mobility.We propose a distributed pre-caching method for seamless communication,taking advantage of user's mobility and data object's popularity information to decide which base station should pre-fetch the data objects,and using the congestion price to utilize cache storage efficiently.This pre-caching approach is applicable to the case where the flat cache structure and the case where the two layer cache hierarchy.In addition,our model architecture considers the case that the delay does not depend on the size of the user requested data objects and the case which delay is a function of the requested object sizes.In this paper,we propose a new method of block pre-caching based on user's mobility,which divides the requested data objects into different data segments and selects a part of them to pre-cache.The simulation results show that the average delay of the block pre-caching algorithm is smaller and the performance is better than the originals.In this paper,we leading into the concept of popularity which based on the premise of the original algorithm,considering from two aspects and according to the prediction of user's transition probability and data object's popularity to adjust cache storage dynamically.The simulation results show that the performance of the pre-caching algorithm which based on user's mobility and the popularity of the data object is better than the pre-caching algorithm based on user's mobility,and the cache hit rate is higher.