Planning of Long Range VHF Communication Systems for Police Radio Services

Abstract

On account of severe congestion in high frequency bands, future expansion of Police Radio Communication will be in VHF/Microwave region. Factors affecting range of communication in these frequency bands, like line of sight, refraction, diffraction, reflection, scattering, transmission and absorption have been discussed in this paper. Emphasis has been given on ‘Diffraction’ as this is the factor which is generally ignored in calculating antenna heights and locations of relaying stations. It has been established that this factor, if taken into account, will considerably reduce the cost of installations. Concrete problems of large range communication coverage for the state of Uttar Pradesh have been analysed.