A method for deregistering wireless devices from a registration server for a wireless local area network, comprising: sending an initial registration request message from a wireless device to the registration server, the initial registration request message including an initial expiration interval; measuring radio signal strength at the wireless device; and, determining whether the radio signal strength has decreased to below a predetermined level and, if so, sending an updated registration request message from the wireless device to the registration server, the updated registration request message including an updated expiration interval less than the initial expiration interval thereby allowing timely deregistering of the wireless device by the registration server.