Mode Selection for 5G Heterogeneous and Opportunistic Networks

5G and beyond networks will offer multiple communication modes including device-to-device and multi-hop cellular (or UE-to-network relay) communications. Several studies have shown that these modes can significantly improve the Quality of Service (QoS), the spectrum and energy efficiency, and the network capacity. Recent studies have demonstrated that further gains can be achieved when integrating demand-driven opportunistic networking into Multi-Hop Cellular Networks (MCN). In opportunistic MCN connections, devices can exploit the delay tolerance of many mobile data services to search for the most efficient connections between nodes. The availability of multiple communication modes requires mode selection schemes capable to decide the optimum mode for each transmission. Mode selection schemes have been previously proposed to account for the introduction of D2D and MCN. However, existing mode selection schemes cannot integrate opportunistic MCN connections into the selection process. This paper advances the state of the art by proposing the first mode selection scheme capable to integrate opportunistic MCN communications within 5G and beyond networks. The conducted analysis demonstrates the potential of opportunistic MCN communications, and the capability of the proposed mode selection scheme to select the most adequate communication mode.