It is provided a method performed by a beamformer device for channel sounding in a network including a beamformer device and at least one beamformee device. In each round of channel sounding, the beamformer device may send an announcement message including identification information of beamformee devices included in a list when the list is not empty and clearing the list, wherein the beamformee devices included in the list have moved a distance exceeding a threshold value.