Development of a Site-Specific Building Entry Loss Model for High-Rise Buildings

Recently, not only mobile networks using ground base stations but also Non-Terrestrial Networks (NTN) have been attracting attention, and the development of ubiquitous networks combining these networks is expected to expand communication coverage. In order to build such networks efficiently, it is necessary to estimate radio propagation characteristics accurately according to various terrestrial environments. In this paper, the authors focus on the study the radio propagation loss characteristics from outdoor to indoor areas, i.e., Building Entry Loss (BEL). 3rd Generation Partnership Project (3GPP) and International Telecommunication Union Radiocommunication sector (ITU-R) have standardized the BEL models. However, these models are not appropriate detailed studies because of the small number of parameters taken into account. Therefore, the authors carried out field measurements in office buildings with various elevation/azimuth angle between the outdoor station and the building and various location of the indoor station, clarified the BEL characteristics, and developed a site-specific model.