3D UAV BS Positioning and Backhaul Management in Cellular Network Via Stochastic Optimization.

In recent years, using the Unmanned Aerial Vehicle (UAV) as a Base Stations (BS) to cover users in wireless networks has increased dramatically. One of the main goals of integrating UAVs into wireless networks is to deploy UAVs in such a way that user expectations are met with the fewest number of UAVs. To achieve this aim, the coverage area of each UAV should include as many users as possible. Furthermore, the resources assigned to the backhaul links for such UAV deployments must fulfill the requirements of users served by each UAV. In this paper the goal is to position the least number of UAVs in a 3D position to cover cellular network users. To provide appropriate quality of service, we consider a maximum path loss allowed for the network. The path loss of potential links is affected by the propagation environment and might vary depending on network structure. To reflect this uncertainty, path loss is expressed as a random variable with a probability distribution based on environmental characteristics. As a result, we're dealing with an optimization problem with uncertain information. We use stochastic programming to work with uncertain information and formulate the UAV positioning and data rate assignment problem. The implementation results of our proposed mixed-binary linear mathematical model and Monte Carlo simulation in various scenarios show its optimum performance in different dimensions.