Energy-Efficient D2D Discovery for Proximity Services in 3GPP LTE-Advanced Networks: ProSe Discovery Mechanisms

Device-to-device (D2D) communications facilitate promising solutions for service optimization and spectrum/capacity efficiency in the Third-Generation Partnership Project (3GPP) networks. A key enabler for D2D communications and proximity services (ProSe) is the device discovery process. Currently, many aggressive peer discovery methods discussed in 3GPP could induce high energy consumption. Therefore, a critical objective in efficient D2D proximity service deployments is how to prolong the battery life time of user equipments (UEs) by managing discovery cycles intelligently. In this article, D2D discovery mechanisms discussed in the 3GPP are studied in terms of energy consumption aspects. In particular, we consider an efficient D2D discovery mechanism that takes advantage of the concept of proximity area (P-Area), a dynamic geographical region wherein UEs activate their D2D capabilities. The mechanism enables UEs to perform D2D discovery procedures only when there is a high probability to find other UEs subscribed to the same service. The energy consumption profiles of various discovery mechanisms are evaluated using simulations, and the results indicate that significant energy savings can be obtained using the considered discovery mechanism.