Review on UAV-based FSO links: recent advances, challenges, and performance metrics

With the rapid advancements in wireless technology, the incorporation of unmanned aerial vehicles (UAVs) in free space optical (FSO) communication can reap several benefits related to coverage, security, and capacity. The parameters involved for the analysis of such systems are studied in detail. The irradiance fluctuations in the received beam due to turbulence induced fading and geometric and misalignment effects are to be taken care of in order to minimize the bit error rate. The random variables involved in a UAV-employed FSO link are larger than that present in an FSO system. Thus, efficient designing of a UAV-employed FSO system is relatively more challenging as compared to a ground-based terrestrial FSO link. There are many performance metrics that can be defined and are to be analyzed in order to optimize the parameters associated with UAV-based FSO systems and design a link with good quality of service. Some recent methods are also explored for further improving the reliability and coverage of UAV based FSO networks.