Radio network design-considerations to minimise effects of signal fading

Point-to-point or point-to-multipoint communication networks are being used for a variety of applications like voice, data supervisory control and data acquistion (SCADA) and automatic electric utility meter reading etc. Options for the network designers are the frequency, transmitter power and bandwidth for each of the above-mentioned applications. Typical design approaches do not ensure electromagnetic compatible operation of the network, resulting unknown signal fading and sometimes even signal loss, making the network unreliable, for an optimum transmitter power. This paper brings out various considerations to minimise the effect signal fading in a dynamically changing environment, which causes different multi-paths for the link. Further a quantitative estimation of fading based on a new distribution function, is shown which improves the accuracy of prediction of the electric field strength in urban areas. A software package "radio network design" is developed based on this concept and used in the design of three major networks in India.