In a packet-based communication network a central control unit indicates its presence on the first channel by in addition to data traffic transmits regular beacons with a specified time interval, and upon detecting radar signals on a first channel the central control unit transmits a channel switch message and immediately switches to a second channel and resumes data traffic on that second channel, thereafter repeatedly transmitting a channel switch message on the first channel and a beacon on the second channel by switching back to the first channel to transmit second channel switch messages (either contained in beacons or separately) and switching back to the second channel to transmit regular beacons for each permissible beacon transmission time slot, until as many devices as possible associated with the central control unit has followed to the second channel.