Coverage Estimation Using Probabilistic Line-of-Sight Model for Unmanned Aerial Vehicle Communication

Aerial platforms have recently gained significant popularity for the rapid development of relief networks in emergencies. These platforms are capable to deliver essential wireless communication for various applications such as public safety, natural disasters, or adding coverage to existing terrestrial networks. A reliable prediction of coverage resulting from an aerial base station is important to provide essential air-to-ground wireless services for disaster-affected areas. Line-of-sight (LoS) is an essential component of air-to-ground wireless channels, particularly useful for radio planning and coverage prediction. The performance of an air-to-ground link can be evaluated on three key parameters: elevation angle, communication range, and altitude between the aerial base station and ground receiver. In this paper, we proposed an elevation-dependent line-of-sight model to estimate the area coverage of an aerial base station. The proposed model is derived from statistical parameters of building distribution, defined by the International Telecommunication Union for four urban environments: urban, suburban, dense urban, and high-rise urban. Coverage of aerial base station is estimated from building blockage probability which is formulated as a weighted function of the developed LoS model. Estimated coverage is simulated for elevation angle and communication range between UAV and ground receiver for low altitudes up to 500 m. We restricted UAV altitude up to 500 m due to the limitation on flying altitude by regulating authorities. Our results contribute to identifying the optimum elevation angle and communication range between UAV and ground receiver for line-of-sight communication. Based on the results, we deduced that the optimum elevation angle to attain 100% coverage is between 60 and 80° for all urban environments. We observed a significant reduction in the communication range with declination in UAV altitude, to attain the same amount of coverage for urban, dense urban, and high-rise urban environments. For suburban, altitude is not playing a significant role in the range of communication to achieve area coverage.