A Realistic Approach to Enhance the Battery Performance of Device-to-Device (D2D) Relay UEs

The unprecedented trends in Proximity-based services (ProSe) have intensified the need for the Device- to- Device (D2D) communication in the next generation 5G cellular networks. ProSe allows devices in the proximity to discover and communicate with each other directly. In Prose, a Relay User Equipment (UE) is a wireless communication device which enables UEs not in presence of network coverage to connect to the network by using sidelink channel. Relay UE executes periodic discovery procedures to enable other devices to know about its presence. These periodic discovery transmissions consume a significant power on the relay UE. In the presence of multiple relay UEs operating within a close proximity, most of these operations might be redundant as all the relay UEs are operated independently. In this work, we propose a novel solution to minimize the periodic discovery transmissions by establishing a co-ordinated relay discovery mechanism. Using extensive simulations, we have shown our proposed algorithm helps in reducing the energy consumption of relay UEs significantly by selecting operating modes appropriately.