A method for detecting a channel-free or busy condition in a communication system with direct mode, comprising a first transmitting transceiver (10) and a second receiving transceiver (12) that communicate on a first communication channel, and at least a third transceiver (14) comprises monitoring the first communication channel to each signaling activity; with the following steps: Periodically transmitting a broadcast signal by the second transceiver (12) as long as it receives communication signals from the first transceiver (10) over the first communication channel in direct mode; Monitoring said first communication channel by the third transceiver (14), and Receiving the broadcast signal at the third transceiver (14) to indicate to him that the first communication channel is busy.