Social-Aware Spectrum Sharing and Caching Helper Selection Strategy Optimized Multicast Video Streaming in Dense D2D 5G Networks

The expected explosion of video traffic in 5G ultradense networks will pose many challenges to the Internet service providers, e.g., degraded capacity and unfair quality of service (QoS). The most efficient solution is resource allocation that does not require any network architecture changes. This article proposes a social-aware spectrum sharing and caching helper selection (SSC) strategy that exploits the resources of the mobile users (MUs), i.e., downlink spectrum resources for sharing and caching storage resources for multicasting, to offload the videos in dense device-to-device (D2D) 5G networks. Particularly, we consider physical and social attributes of the MUs to formulate an SSC optimization problem. The SSC problem is solved to optimally control: which MUs, namely sharing mobile users (SUs), that share the downlink spectrum resources and which MUs, namely caching mobile helpers, that cache the requested videos for D2D multicast communications by reusing the shared downlink spectrum resources. The objective is to maximize the system capacity while satisfying the constraints on capacity fluctuation among the receiving mobile users (RUs) and target signal-to-interference-plus-noise ratio at the SUs, to guarantee the RUs and the SUs high QoS fairness. Simulation results are shown to demonstrate the benefits of the SSC strategy.