Research Of D2D Caching Strategy In 5G

With the rapidly development of the mobile devices,global mobile data traffic,mainly generated by the on-demand video streaming,will increase by 7 times in the next five years.Such explosive growth brings enormous burden on the currently network.D2D communication is one of the key technologies of 5G.By applying caching into D2D communication network,contents can be cached in devices to construct D2D caching network to reduce consumption of network resource.The most existing caching strategies in D2D are proactive caching,which need to make prediction of users' preference and pre-cache content in devices.However,short videos are posted by users in any time and it's hard to predict their popularity.Therefore,in this paper,we propose two reactive social-aware D2D caching strategies.The contributions of this paper include:1.Proposing a Indian Buffet Process based social-aware D2D caching strategy(IBPSC).We construct a reliable D2D communication network according to geographical closeness.Then,several social communities are constructed according to online interest similarity and influence degree is proposed to mark users.The request process of users is modeled by Indian buffet process and the contribution degree is defined.Within a community,each device ranked by influence degree makes caching decision according to the contribution of caching content to other devices in same community.2.Proposing a network coding based social-aware caching strategy(NCSD)to further improve the system performance.In this strategy,network coding(NC)is applied.All devices cache coded blocks.The number of coded blocks cached is determined by the contribution of caching content to other devices in same community.