Evaluation of Rain Attenuation Models for 5G Frequencies: Regions in Turkey

Abstract

Rain attenuation in 5G satellite communications needs to be considered in planning the communication settings due to the fact that it causes significant attenuation especially above 10 GHz and in low elevation angle Earth-space connection paths. Even though various rain attenuation models have been developed by using measured meteorological data, it is important to know especially which model provides better results for 5G frequencies since direct satellite communication over 5G channels is planned to be used in the near feature. Hence, in this study, prominent rain attenuation models such as the Simple Attenuation Model, Garcia-Lopez model, and ITU-R P.618-14 model were examined. Using these models, rain attenuations occurring at elevation angles of 30°, 60°, and 85° were identified in three different cities in Turkey. Average annual precipitation data from the General Directorate of Meteorology of Turkey for the years 1930-2023 were utilized. The studies on various rain models using different parameters revealed that the attenuation in the 470-780 MHz frequency band is 2.849x10-4 dB, whereas there is a 12.63 dB attenuation in the range of 40.5-43.5 GHz. It was observed that the attenuation increases further with frequencies above 43.5 GHz. Therefore, it is evident that rain attenuation is a crucial parameter in satellite communication systems, particularly in 5G and beyond. This study has revealed that ITU-R P.618-14 model is the best suitable one for high elevation angles and at high frequencies (above 40GHz). As for lower elevation angles Garcia model is more appropriate.