Handover Probability in 3D Mobile UAV Cellular Networks

The use of unmanned aerial vehicles (UAVs) as base stations (BSs) is a promising solution to enhance the performance of the cellular networks. This architecture enables greater mobility for BSs, which affects both communication distance and the probability of line-of-sight (LoS) and non-line-of-sight (NLoS) links in air-to-ground channels. Consequently, handovers occur frequently, impacting communication performance. However, the analytical impact of LoS and NLoS links on handover probability in mobile UAV networks remains unknown. In this paper, we employ the random geometry theory to comprehensively investigate the impact of LoS link probability on handover while considering two association strategies based on the nearest-distance and the strongest average received signal strength. We present exact expressions for handover probability in semi-closed form under these two scenarios. Our proposed analytical results enable the exploration into how UAV-BSs density, the deployment height, and the adopted association strategy affect the handover probability.