Communication environment with a plurality of radio systems

摘要

The communications environment contains a number of radio systems (1-4), each having at least one radio station (5-9, 10, 11, 12-15, 16-19), tested prior to transmission to verify the availability of the required frequency slot. A pair of random pulses within the required frequency slot are subsequently transmitted, in order to detect for collision with a different radio system. If no collision is detected then the useful signals are transmitted.