Design and Implementation of a Neighbor Discovery Framework Through Base Station Coordination for 5G D2D Communications

With the rapid advancement in cellular communications, there has been significant growth in the number of connected devices like smartphones, tablets, and wearables. Device-to-Device (D2D) communication is one of the emerging technologies to support future generations of Cellular Networks. It improves throughput, energy efficiency and reduces delay by allowing proximal devices to communicate directly. Device discovery is the initial and one of the crucial phases to enable D2D communication. In order to have direct communication, the devices need to find other devices in their proximity. A network-assisted discovery mechanism relying on the serving Base Station (BS) provides incomplete neighborhood information, whereas discovery, if performed by the user equipment(UE)s themselves, increases the number of discovery message exchanges in the network. In this regard, we propose a robust D2D Discovery framework that leverages the collective knowledge of neighboring Base Stations to provide complete neighborhood information. We implement and evaluate our proposed framework on the D2D module of the NS3 simulator. We demonstrate the improvement in terms of the number of discovered UEs, reduction in number of missed UEs compared to existing network-assisted discovery mechanisms, and reduced number of discovery message exchanges compared to the state-of-the-art 3GPP standards.