Downlink Resource Allocation Maximized Video Delivery Capacity over Multi-hop Multi-path in Dense D2D 5G Networks

One of the significant challenges to 5G networks is how to serve a proliferation of dense mobile users (MUs) various video applications and services (VASs) at high delivery capacity under a scarcity of resources. In this paper, we exploit the resources of dense MUs to establish a set of device-to-device (D2D) multi-hop multi-path (MHMP) communications that can assist the macro base station (MBS) to offload the videos. Particularly, there are three types of MUs including cellular MUs (CUs), source MUs (SUs), and relay MUs, which are willing to share the downlink spectrum resources, provide the cached videos, and forward the videos, respectively. A downlink resource allocation for D2D MHMP communications (DRA-DMC) optimization problem is formulated to find the optimal allocation pairs of CUs and D2D hops in each path from the SUs to a destination MU (DU). Consequently, the DU can receive the videos flexibly from both the MBS and the SUs over D2D MHMP communications by reusing the downlink resources of the CUs, at maximum delivery capacity. Simulation results are performed to demonstrate the benefits of the DRA-DMC solution compared to other conventional schemes.