Patent ID: 7411979

Claim:
A method for handling discarding of a sequence of service data units in a communications system, the sequence of service data units comprising at least a last discarded service data unit (SDU), the method comprising the following steps: when a protocol data unit (PDU) containing a length indicator of the last discarded SDU contains no new SDUs: creating a move receiving window super field (MRW SUFI); setting a N LENGTH field of the MRW SUFI to 0; setting a last sequence number move receiving window field (SN_MRW LENGTH ) to a sum of one plus a sequence number (SN) of the PDU containing the length indicator of the last discarded SDU; and issuing the MRW SUFI; wherein the length indicator indicates an end position of the last discarded SDU; the SN_MRW LENGTH indicates a sequence number of a PDU that contains a data segment of a SDU right after the last discarded SDU; setting the N LENGTH field of the MRW SUFI to 0 indicates that the last SDU discarded ended in a PDU with sequence number SN_MRW LENGTH -1 and that the first data octet in a PDU with sequence number SN_MRW LENGTH is the first data octet of the SDU right after the last discarded SDU; and the MRW SUFI is used to signal the information of discarded SDUs.