Cloud Aware Dynamic UAV Operation for 6G FSO Backhaul Network Performance Improvement

Non-terrestrial networks (NTNs) that support communication via unmanned aerial vehicles (UAVs) in 6G systems are attracting considerable interest. To meet the quality of service (QoS) requirements for future 6G devices, the backhaul network of NTNs must provide higher throughput and more secure wireless connectivity. It is anticipated that backhaul NTNs with high throughput free space optical (FSO) communication will play a significant role in supporting multiple users. However, establishing a stable FSO communication link using UAVs can be disrupted by various obstacles, including clouds and atmospheric conditions. To address this challenge, it is essential to consider the effect of clouds on the FSO backhaul network. In this paper, the method for optimizing the deployment of multiple UAVs considering the probability of cloud attenuation is proposed. Specifically, this paper presents a cloud-aware dynamic UAV operation (CDUO) scheme, which contains an optimization process using the generalized Lagrange multiplier method (GLMM). Simulation results (based on blimp-type unmanned aerial stations (UASs)) show that the CDUO scheme can provide a superior outage probability performance compared to existing schemes. The CDUO scheme can be utilized in NTNs that operate above the clouds.