Asynchronous LOS Discovery Algorithm for Aerial Nodes Using In-band Full-Duplex Transceivers

Emerging communication techniques in terahertz bands, including free-space optical (FSO), have the potential to aid in solving the spectrum scarcity problem by complementing the traditional radio frequency (RF) wireless networks. Line-of-Sight (LOS) link discovery is one of the major limiting factors for these highly directional bands, and this problem of establishing LOS between neighbor nodes becomes more challenging when they have no a-priory knowledge of the location of each other. In this work, we present an asynchronous LOS discovery algorithm using spiral scanning without any synchronization via an RF channel. We also demonstrate the effectiveness of the algorithm through test-bed experiments using a prototype of UAVs equipped with in-band full-duplex (IBFD) FSO transceivers.