Clear air interference predictions in tropospheric radio wave propagation: Indian experiences

Abstract

Interference predictions are vital components of system design especially in broadcast services for predicting the coverage area of own transmitters as well as for assessing the signal strength of interfering transmitters. The problems associated with ITU-R interference predictions related to tropospheric radio wave propagation are discussed. Based on the experiences of analysing data of interfering signals at VHF and above, a new prediction procedure is advocated after taking into consideration all the propagation mechanisms in demarcating coordination distances. This approach can be very useful in spectrum management applications for FM and TV transmitters in the VHF and UHF bands, particularly for tropical countries where abnormal propagation conditions prevail for most of the time.