METHOD AND APPARATUS FOR PERFORMING HANDOVER WITH RELAY NODE

摘要

PROBLEM TO BE SOLVED: To reduce or avoid data re-forwarding from an RN to a DeNB during handover, and to minimize the amount of data transferred from the DeNB to the RN that needs to be re-forwarded back to a serving DeNB during handover, and reduce the handover completion time due to unnecessary data exchange between the RN and the serving DeNB.SOLUTION: An RN receives data from one of an eNB and a WTRU and forwards it to the other. The RN receives a PDCP PDU from a serving DeNB and transmits it to the WTRU. The RN makes a handover decision on the basis of a measurement report received from the WTRU, and then sends a handover request or a control message to the serving DeNB including a first unsuccessfully transmitted PDCP sequence number. The serving DeNB then discards a PDCP PDU with an SN older than the first unsuccessfully transmitted PDCP SN.