Patent ID: 9241291
Filing Date: 2016-01-19
CPC Classification: H04W

Claim Text:
1. A method for reducing handover interruption time at a mobile station, the method comprising: transmitting a handover request message to a serving base station; receiving a handover response message from the serving base station that includes a dedicated ranging code of each of at least one candidate base station, wherein the handover response message further includes action time information for a pre-synchronization procedure and is related to the handover request message; receiving an uplink-MAP including a ranging channel allocation from a target base station after lapse of an action time for the pre-synchronization procedure indicated by the action time information; transmitting a dedicated ranging code to the target base station during the pre-synchronization procedure, wherein the dedicated ranging code is allocated by the target base station; and performing, after the pre-synchronization procedure, a ranging procedure with the target base station by using the dedicated ranging code, if a handover command message, from the serving base station, is received.