Human Body Shielding Loss Model with Frequency Characteristics for HAPS Communication

High-Altitude Platform Station (HAPS), which provides communications services from an altitude of 20 km via an Unmanned Aerial Vehicle (UAV), is attracting much attention as a new mobile communications platform for ultra-wide coverage areas and disaster-resilient networks. HAPS can provide mobile communications services directly to smartphones, but requires a propagation loss model of human shielding that can consider elevation angles in various environments. In this paper, we propose a propagation loss model of human body shielding with frequency characteristics in HAPS communications.