Research On Video Transmission In DEVICE-TO-DEVICE Caching Cellular Networks

Recently,the explosive increasing mobile data traffic and the ever-increasing demand for high-quality and low-latency mobile video streams have brought great challenges to the mobile cellular network with limited backhaul capacity.Particularly,a numerous amount of video traffic is caused by a small fraction of popular video files.Taking advantage of content redundancy in reducing data traffic load,proactive caching,which caches some popular files in local user devices,has attracted much attention.Device-to-Device(D2D)communications,which has both high Signal-to-Interference-plus-Noise-Ratio(SINR)and high structural flexibility,is also one of the popular strategies in reducing the data traffic load in the cellular networks.Local D2D caching cannot only reduce repetitive video traffic load,but also can take advantages of D2D links to improve the cache hit probability,which in turn promotes the overall performance of the networks.The D2D caching cellular network model and the Scalable Video Code(SVC)video transmission model are studied.Firstly,the D2D communication technology,caching technology,SVC technology and their research background are overviewed.Then the theory of related works and studies are summarized.Finally,we propose a D2D caching model and a SVC video transmission strategy.The SVC video transmission in D2D caching cellular networks is studied.To address the diverse demands of mobile video,we introduce SVC technology into the D2D caching communities.Considering the influence of different types of video quality preference,the system uses two traditional caching strategies to compare,and the theoretical analysis of the different parameters on the transmission performance of the system is proposed.Then simulation results demonstrate that two caching strategies can both improve the system performance,and show the dependence between the system caching hit probability and the user satisfaction.In order to realize the cache placement problem of the SVC video in the D2D caching cellular networks,we study the SVC video cache strategy based on the cache hit probability.A SVC video cache optimal strategy originated from the probabilistic cache policy is proposed.Simulation results reveal that the proposed caching strategy outperforms existing works.