Rain attenuation measurements over terrestrial microwave links operating at 15 GHz in Malaysia

Abstract

This paper presents the experimental results of rain rate and rain attenuation measurements on six terrestrial microwave links in tropical Malaysia. The rain attenuation data were collected from six DIGI MINI-LINKs (DiGi Telecommunications Sdn. Bhd., Malaysia, Shah Alam, Selangor Darul Ehsan, Malaysia) operating at 15 GHz with 99.95 % availability. The experimental results were compared with the International Telecommunication Union Radiocommunication Sector (ITU-R) method and other existing rain attenuation prediction models. The main focus is on the ITU-R prediction method, which underestimates the measured rain attenuation, more especially at extremely higher rain rates. The relationship between ITU-R prediction errors and rainfall rates was studied, and it is shown that the two quantities are related by a quadratic function. The study will provide useful information on the design and planning of terrestrial radio links in Malaysia and similar tropical environments.