Vertical and Horizontal Building Entry Loss Measurement in 4.9 GHz Band by Unmanned Aerial Vehicle

Abstract

User traffic of mobile wireless communication is rapidly increasing in urban areas. Thus, service cell planning becomes an important issue for efficient radio resource usage. Since users are also inside high buildings in those areas, it is important to know the building entry loss (BEL) characteristics from the outside base stations of various locations for the purpose. In this letter, we measured the penetration loss of buildings with large windows in the 4.9 GHz band by using a system with an unmanned aerial vehicle. Our contribution is to clarify the vertical-horizontal BEL characteristics through exhaustive measurements. We also extended the COST 231 BEL model for the vertical-horizontal BEL characteristics, and estimated the model parameters from the measurements. The results showed that the vertical-horizontal domain BEL characteristics were quite different, but that they were not independent. The proposed model improved the root mean squared error of the BEL prediction by approximately 3 dB. This is expected to be utilized for the improvement of cell planning efficiency.