Spectrum Sharing and Power Allocation Optimised Multihop Multipath D2D Video Delivery in Beyond 5G Networks

In this paper, we propose a joint spectrum and power optimisation (SPO) for multi-hop multi-path (MHMP) device-to-device (D2D) video delivery in beyond 5G (B5G/6G) networks, where the system resources such as spectrum, energy, storage, and content of mobile users (MUs), are taken into account. Particularly, the downlink spectrum resources of the sharing users (SUs) are reused by the transmitters (TXs) of D2D hops and the energy resources of the TXs are utilized for D2D communications. We further exploit the videos stored in the caching users (CUs) located more than one D2D hop far away from the requesting users (RUs) to establish MHMP D2D video delivery sessions from the CUs to the RUs. Then, the SPO problem is formulated for the optimal spectrum sharing pairs of SUs and TXs and the optimal transmission powers allocated to the TXs. Genetic algorithms (GAs) are developed to solve the SPO problem with respect to both binary variable (spectrum sharing) and real variable (power allocation). The SPO solution allows the RUs to alternately request the videos not only from the macro base station over conventional cellular networks but also from the CUs over MHMP D2D communications at the highest quality of service, i.e., maximum video delivery capacity and low power consumption. Simulation results are analysed to demonstrate the feasibility of GAs and the benefits of the proposed SPO solution in comparison with other conventional schemes.