Patent ID: 8781471
Filing Date: 2014-07-15
Classification: H04W

Abstract:
1. A method of performing a handover operation in a wireless communication system, the method comprising: communicating signal measurement information to a source base station; receiving a handover command from the source base station; receiving a dedicated random access signature, a signature expiration time and information related to validity of the dedicated random access signature from a target base station, wherein the dedicated random access signature and the signature expiration time are reserved by the target base station; transmitting a first random access preamble using the dedicated random access signature to the target base station; receiving a new dedicated random access signature and a new signature expiration time from the target base station, when the first random access preamble is not received at the target base station when the signature expiration time expires; and retransmitting a second random access preamble using the new dedicated random access signature to the target base station, wherein the new dedicated random access signature is same as the dedicated random access signature.