Measurement and analysis of building entry loss in High base station environment

High-Altitude Platform Station (HAPS), which provides communication 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. A HAPS can provide mobile communications services directly to smartphones. In order to design efficient cell configurations for HAPS-based services, we need a radio wave propagation model that takes into consideration factors such as terrain, vegetation, urban areas, suburban areas, and building entry loss. We measure and clarify the building entry loss characteristics at various elevation and azimuth angles environment. In this paper, based on measured results, we identified the key parameters required for the site-specific building entry loss model and proposed a site-specific model.