In one embodiment, a network system has a plurality of access points, wherein each access point can be used for wireless communication with at least one station, wherein each access point can (1) receive a probe signal with either a first or second channel frequency and (2) generate and transmit, in response to the probe signal, a response signal with the first or second channel frequency. At least one access point selects at least one channel frequency for the wireless communication with the at least one station on the basis of at least one response signal received with the first channel frequency as transmitted by any of the other access points and/or at least one response signal received with the second channel frequency as transmitted by any of the other access points.