Energy-Efficient Device Discovery Mechanism for Device-to-Device Communications in 5G Networks

The conventional direct device discovery scheme which uses the random access protocol and encounters contentions or collisions is highly energy time-consuming. To reduce consumption of user equipments (UEs), this work proposes a two-phase hybrid mechanism for device-to-device (D2D) communications. In first phase, evolved packet core (EPC) base station (BS) location information UEs to judge whether two are able establish D2D link. second use Wi-Fi Direct discover their target UEs. BS directly assigns UEs’ states allocates appropriate channels no longer have search listen all channels, thus reducing delay. proposed saves cellular spectrum resources because it unlicensed bands performance also theoretically analyzed in paper. Evaluation results show that has better terms consumption, delay success rate, compared with scheme, especially network scenarios smaller cells such as 5G networks. Additionally, analytic coincide simulation results, demonstrating our theoretic analysis accurate.