Estimation of rain attenuation losses in signal link for microwave frequencies using ITU-R model

Estimation of rain attenuation is an important parameter for the designing of both satellite and terrestrial communications links operating in a tropical country like India especially for microwave frequencies above 10 GHz. The present study uses the ITU-R P618-8 rain attenuation model to determine the signal loss in the transmission link for microwave frequencies of 20.2 and 30.5 GHz at New Delhi. For this purpose, 1-hourly Automatic Weather Station (AWS) rain rate has been converted to 1-minute integration time using ITU-R P837-6, before being used in the attenuation model. Analysis suggests that the rain attenuation is directly proportional to the rain rate and microwave frequencies. Moreover, it has also been observed that if frequency increases by approximately 10 GHz, the percentage increase in the attenuation at New Delhi would be approximately 38% respectively. The preliminary results are encouraging and may be utilized to conduct the attenuation studies for forthcoming microwave frequency links in tropical regions in detailed manner for other spatial locations as well.