Abstract: In order to establish communications in a conference network of transmitter-receiver stations, each station establishes a frequency-jumping standby law while a calling station transmits a frequency-diversity call sequence on said standby law and the other stations are listening in accordance with said standby law. Furthermore, each station establishes a second frequency law which is synchronous with the standby law but the stair-steps of which are of longer duration. At the end of a call sequence, the calling station and the stations which have detected this sequence are put in the listening state over a time interval t.sub.1 at the corresponding possible traffic frequency of the second frequency law. Each station which has detected a signal then transmits a jamming signal over a time interval t.sub.2 at the aforementioned traffic frequency and the stations which have not detected any signal extend the listening period by the same time interval t.sub.2. Non-reception of a signal during the time interval t.