LOS discovery for highly directional full duplex RF/FSO transceivers

Full duplex directional Radio Frequency (RF) / Free-Space-Optical (FSO) transceivers are envisioned to play a great role in future generation wireless networks. They provide benefits in terms of better throughput, enhanced spectrum utilization and lower interference from unwanted sources. However, the stringent requirement of line-of-sight (LOS) communication makes it tough for a mobile node to maintain a link without a-priori information about its neighbor's position. Hence, neighbor discovery takes a very crucial role in mobile ad hoc networks with directional transceivers. In this paper, we focus on neighbor discovery using full duplex directional transceivers. We consider two nodes that can discover each other by steering their transceivers with a randomly chosen angular speed and performing a simple three way handshaking protocol. We provide a theoretical analysis of the proposed neighbor discovery method. Additionally, we propose an algorithm where each node chooses its transceiver's angular speed and renews it if the neighbor is not discovered within an optimal time interval. We evaluate the algorithm via simulations and show its effectiveness under various scenarios.