Radio Propagation Variations at VHF and UHF

The variations of received signal with location (shadow losses) and with time (fading) greatly affect both the usable service area and the required geographical separation between cochannel stations. An empirical method is given for estimating the magnitude of these variations at vhf and uhf. These data indicate that the required separation between co-channel stations is from 3 to 10 times the average radius of the usable coverage area, and depends on the type of service and on the degree of reliability required. The application of this method is illustrated by examples in the mobile radiotelephone field.