Patent ID: 7957349
Filing Date: 2011-06-07
Classification: H04W

Abstract:
1. A method for performing a handover from a source cell to a target cell in a mobile communication system, the method comprising: sending, by a User Equipment (UE), a measurement report on received signal strengths of adjacent cells, to a Node B of the source cell; determining, by the Node B of the source cell, a handover of the UE based on the measurement report; sending, by the Node B of the source cell, a handover preparation message to the UE; performing, by the Node B of the source cell, a handover preparation process with a Node B of the target cell; after receiving the handover preparation message, sending, by the UE, to the Node B of the source cell, a status report including a sequence number of successfully received packet data and a sequence number of missing packet data; discarding, by the Node B of the source cell, the successfully received packet data, retransmitting the missing packet data to the UE, and forwarding an un-acknowledged packet data to the Node B of the target cell, based on the sequence numbers included in the received status report; and upon a receipt of a handover command from the Node B of the source cell, performing a handover by the UE.