Superimposing radio signals in selected region by announcements - determining transmission levels of priority signals needed to cover actual reception levels

摘要

The carrier frequencies and the levels of reception of the radio signals are determined at least in one representative place inside the region. The transmission levels for the priority signals needed to cover the actual reception levels are determined in relation to these latter levels for all the carrier frequencies involved. The priority signals are transmitted sequentially, in groups or parallel, on carriers with frequencies corresp to the carrier frequencies already determined and at the level already determined. USE/ADVANTAGE - e.g. for VHF receiver. Alarms or warning signals can be received by any receiver which is switched on or even if sound is turned down.