A method of selectively enabling one of a first and a second operating mode in a first network device is presented. The first network device has a wireless receiver and transmitter for providing bi-directional communication with a mobile station through a first wireless link, for providing access to a network. In the first operating mode the wireless transmitter is not continuously enabled, and in the second operating mode the wireless transmitter is continuously enabled. In the first operating mode the first network device, receives, from a second network device, status information about a second wireless link maintained between the second network device and the mobile station, and sends, at predetermined time intervals, probe requests to the mobile station. The wireless transmitter is enabled for sending the probe request and disabled thereafter. The first network device receives a response to the probe request from the mobile station and determines a spatial distance of the mobile station to the first network device and to the second network device. Depending on the determined distance the first network device switches to the second operating mode, allowing association of the mobile station with the first network device via the first wireless link.