Patent ID: 8478268

Claim:
A method of communicating data for performing network re-entry of a mobile station (MS) in a wireless communication system, the method comprising: transmitting a deregistration request message comprising first idle-mode retain information to a first network entity; receiving a deregistration command message comprising second idle-mode retain information; deregistering from the first network entity and entering an idle mode; and performing a network re-entry with a second network entity based on information retained for expediting the network re-entry, wherein each of the first and the second idle-mode retain information indicates MS service and operational information to be retained, wherein the MS service and operational information includes capability information, security information, registration information, and network address information, wherein each of the first and the second idle-mode retain information has a bitmap form, and wherein each bit location of the bitmap indicates capability information, the security information, the registration information, or network address information.