Patent ID: 7818006
Filing Date: 2010-10-19
Classification: H04W

Abstract:
1. A method of performing handover operation in a wireless communication system, the method comprising: communicating with a serving base station through a first communication connection using connection resources, wherein the serving base station retains the connection resources for a mobile subscriber station; receiving from the serving base station, a handover response message associated with at least one candidate target base station, wherein the handover response message comprises at least a quality of service capable of being handled by the at least one candidate target base station; determining whether to perform a handover operation in response to the handover response message; if the handover is to be performed, transmitting a first handover indicator to the serving base station indicating that the subscriber station is to undergo the handover operation to a selected target base station of the least one candidate target base station; performing a ranging procedure with the selected target base station to establish a second communication connection with the selected target base station, wherein the ranging procedure comprises receiving ranging information from the selected target base station and attempting to establish an uplink synchronization and power adjustment between the mobile subscriber station and the selected target base station while the serving base station retains the connection resources for the mobile subscriber station; transmitting a second handover indicator indicating a handover cancel upon a failure to establish the second communication connection with the selected target base station; and after the transmitting of the second handover indicator, resuming normal communication with the serving base station using the retained connection resources.