LAUSR

When serving urban hotspots, UAVs are distributed in finite three-dimensional (3D) area and the building blockage further aggravates signal and topology fluctuation, which has not been modeled and analyzed in current works. In this letter, considering the fluctuation of the topology and channel, the exact expressions of temporal correlation and joint coverage are derived, where all UAVs move independently in spatial and vertical directions according to random waypoint (RWP) mobility process within finite 3D area and the impact of building blockage effect is theoretically characterized. Specifically, the distance distribution between the UAV and user is derived based on the steady-state non-uniform distribution of the RWP model instead of simplifying with uniform distribution. In addition, since the flexibility of UAV in height, an air-to-ground channel considering the actual 3D blockage effect is applied and the blockage is not only angle-dependent but also distance-dependent. The numerical results analyze the effects of buildings’ geometrical parameters and finite 3D area size parameters on temporal correlation and joint coverage.