Distributed Deployment of Aerial Base Stations Considering LoS/NLoS Conditions

Aerial base stations (ABSs), i.e., unmanned aerial vehicle-mounted base stations, have emerged as an essential technology to expand the coverage and capacity in next-generation wireless networks. Determining the optimal ABS placement that maximizes the communication quality of users is a critical but challenging problem due to complex air-to-ground (A2G) channel characteristics and inter-cell interference. Although various ABS deployment methods have been proposed, existing methods do not consider the actual line-of-sight (LoS) and non-LoS (NLoS) conditions of A2G channels properly, assuming a spatially independent probabilistic LoS model to simplify the problem and analysis. In this study, we propose a distributed ABS deployment method considering the actual LoS/NLoS conditions. We model the ABS deployment space as a 3D grid space in which the LoS/NLoS condition between each grid point is given and formulate the ABS deployment problem as the maximization problem of the expected number of covered users. By applying a potential game to the problem, we develop a distributed ABS deployment algorithm that probabilistically converges to a Nash equilibrium that maximizes the objective function. Furthermore, we demonstrate through simulation that the proposed method can improve the actual communication quality of users.