Free Space Optics as Full Duplex Fronthauling for Drone-Assisted Mobile Networks

Drone-assisted mobile networks have been proposed to quickly and flexibly deploy drones over any places of interest (PoI) to relay traffic between a remote terrestrial base station (TBS) and the users in the PoI. Here, a drone is considered to be a small-cell base station that is capable to be deployed very close to users in order to provide a high access network capacity. However, owing to the long distance and high traffic load, the fronthaul link between the TBS and the drone would be the bottleneck of the network. Free space optical (FSO) communications have been proposed as a potential solution to increase the fronthaul link capacity. As compared to RF-based fronthaul link solutions, FSO can achieve higher link capacity over a long distance, lower licensing cost and interference, and more reliable communications to resist interception and eavesdropping, and thus could be more suitable to be applied as the fronthaul link solution. However, there are many existing and unveiled challenges to apply FSO as a full duplex fronthaul link for a drone-assisted mobile network. In this paper, we will explore these challenges and investigate related solutions.