Reliable communications at frequencies bands above 25 GHz in the tropics

Abstract

The use of frequencies in the higher bands could tap upon the large spectrum available for communication use. However, it suffers greater propagation losses, making them unsuitable for long range communication. In addition, heavy tropical rain further reduces the reliability of the link and additional link budget has to be set aside for rain fade in order to improve its reliability. Rain attenuation model that has been used widely is currently base on ITU-R model. It gives same rain rate for all places in Malaysia. However, previous study in Malaysia conducted by researchers in UTM shows that rain rate is not the same for different places in Malaysia. It is localized where some places experience heavier rainfall compared to other places. Hence, the ITU-R model does not give an accurate prediction of rain attenuation in Malaysia, where the attenuation is supposed to be localized base on the data of the rain rate. This project is aimed to develop a computer program in order to predict localized rain attenuation. The analysis of calculation to produce rain attenuation is done. The best reduction factor model is chosen to get the most accurate result. Then, the planning is done, followed by the design phase. The most challenging part, which is the development of the program, is done next. To verify the program built, it is tested by entering significant inputs and the outputs are analyzed. As a result, a computer program to predict rain attenuation in Peninsular Malaysia is successfully built. The results produced by the program are compared to the ITU-R model of rain attenuation. The differences are calculated and the outcome shows that ITU-R model is not suitable to be used as a rain attenuation method in Malaysia.