Patent ID: 8041359

Claim:
A method of maintaining a communication link in a communication network comprising: initiating, via a master device, unregistration at a controller having a first wireless coverage area, the unregistration being of a dependent in communication with the master device using a communication channel on a frequency band f band ( 1 ); and transmitting a first message, wirelessly using a frequency f band ( 2 ), from the controller to the dependent indicating to the dependent to register with a network element having a second wireless coverage area, the first wireless coverage area being within the second wireless coverage area, the network element being at a higher level than the master device in a hierarchy of the communication network: and transmitting a second message, wirelessly using the frequency f band ( 2 ), from the controller to the network element indicating to the network element to start communicating with the dependent, wherein the dependent is unregistered based on an unregistration message sent to the controller from the master device when the signal strength of a signal transmitted between the dependent and the master device falls below a threshold value, the signal strength being measured at the master device.