Optimal Placement of Unmanned Aerial Vehicle Base Station.

Abstract

In this research, the optimal placement of unmanned aerial base stations that provide coverage for the ground terminals (users) is analysed and uses the case study of a an MTN malfunctioning terrestrial base station where UAVs are deployed to give coverage to the ground users as the base station problem is being rectified by the maintenance MTN engineers. UAVs provide an efficient solution to achieve wireless connectivity. The aim of this research report is to minimize the number of UAVs needed to be deployed in order to provide wireless coverage to a group of distributed ground users and ensuring that each ground user is in the communication range of at least one UAV. First, the downlink coverage probability for the UAVs to provide coverage to the ground users as a function of the altitude and the antenna gain is derived, this is done for both line of sight and non-line of sight. Next, using circle packing theory, the 3-D locations of the UAVs were determined so that the total coverage area is maximised while maximizing the coverage life of the UAVs. In mitigating interference, the altitudes of the UAVs must be properly adjusted basing on the beamwidth of the direction antennas on the UAVs a well as the coverage requirements. Our results show that the altitude of the UAVs must be adjusted based on the beamwidth of the UAVs’ directional antennas. The minimum number of UAVs needed to give coverage to the desired area with a given radius is determined. The optical altitude and location UAVs can be determined based on the number of UAVs available, antenna gain, and beamwidth. The results show that the proposed algorithm performs favourably compared with other schemes in terms of the required number UAVs as well as coverage life time.