Microwave propagation characteristics under subtropical environment

Abstract

The LOS microwave communication is still in existence in many parts of the world. In a well designed link, the radio waves transmitted from the transmitter reaches the receiver with no deterioration in signal quality, but sometimes it is seen that the radio signal while passing through the medium gets degraded and may at times be lost. As the reception quality of the radio signal is control-led by the environment through which the radio signal propagates, it has been an interesting topic of research since the first installation of LOS link. Though, with the advent of optical communications this mode of propagation is be-lieved to have lost its importance, the operation of LOS links are still very much in existence in this country. So a look on the operational reliability and predict-ability of the microwave hops is worth noting. Degradation of such signal is always measured in terms of attenuation and fading and prediction reliability of such signal is very important, and as a result a number of models with these aims have been developed. But even with all these models and volume of information, there is no single model who can provide a flawless link prediction at different terrain and environmental situations. Such studies also help in un-derstanding the basic physics of the system and more so the coupling proc-esses between earth and the near earth environment as the North Eastern region of India has varied tropospheric and topological characters, a single model will not be sufficient to study and analyse the attenuation or enhance-ment of microwave signal energy at the receiving end. Very little theoretical and experimental work has been carried out over this region, as a result the necessity arises to develop models to improve the quality of signal reception. The aims of this work is based on these facts. For this purpose, links under study are so selected, they have almost same hop length, same topology but located at different situations. 1. Milmilia-Durgasarovar link (frequency 6 GHz and hop length 41.2...