Fade Margin of 15 GHz Microwave Link in GSM Network Based on Rainfall Rate Measured in Chonburi Province

摘要

Atmospheric conditions due to precipitation causes a severe impairment in signal propagation especially to microwave links operating frequencies above 10 GHz. Consequently, the service provider requires a power margin to maintain a fixed outage time. ITU-R model may not sufficiently accurate to predict the rain fading in links located at tropical and equatorial climates which heavy rainfall event is common. This paper presents an experiment to collect yearly cumulative distributions of rain attenuation and rainfall rate compared to ITU-R method. The measurement of received signal level of 15 GHz microwave link in GSM network is conducted in Chonburi province, Thailand eastern. The rain attenuations for horizontally and vertically polarized links are shown. Fade margin at 99.99 % time availability is calculated which are useful for the link design.