Using Unmanned Aerial Vehicles (UAVs) to coverusers in wireless networks has increased in recent years. De-ploying UAVs in appropriate positions is important to coverusers and nodes properly. In this paper, we propose an efficientapproach to determine the minimum number of required UAVsand their optimal positions. To this end, we use an iterativealgorithm that updates the number of required UAVs at eachiteration. To determine the optimal position for the UAVs, wepresent a mathematical model and solve it accurately afterlinearizing. One of the inputs of the mathematical model is aset of candidate points for UAV deployments in2D space. Themathematical model selects a set of points among candidatepoints and determines the altitude of each UAV. To provide asuitable set of candidate points, we also propose a candidatepoint selection method: the MergeCells method. The simulationresults show that the proposed approach performs better thanthe3D P-median approach introduced in the literature. We alsocompare different candidate point selection approaches, and weshow that the MergeCells method outperforms other methods interms of the number of UAVs, user data rates, and simulationtime.

Keywords