Downlink packet data convergence protocol behaviour during handover

摘要

The present invention relates to maintaining an order of received data units during a handover procedure in a wireless communication system. The present invention includes receiving a plurality of data units from a source base station according to a sequence prior to handover to a target base station, wherein each data unit includes a sequence number, receiving at least one data unit having a sequence number after handover from a target base station, and delivering to a higher layer all data units received from the source base station prior to handover and having sequence numbers smaller than a sequence number of the at least one data unit received from the target base station after handover.