Patent ID: 6687248
Filing Date: 2004-02-03
Classification: H04L,H04W

Abstract:
A method for determining sequential ordering of layer 2 protocol data units (PDUs) during a layer 2 move receiving window (MRW) request sent to a receiver in a wireless communications system by a transmitter to discard at least a layer 2 service data unit (SDU), the method comprising:building a layer 2 MRW super-field comprising a: layer 2 PDU sequence number for each layer 2 SDU to be discarded, an initial sequence number arranged within the MRW super-field according to a packing algorithm; and a length field indicating the number of layer 2 PDU sequence numbers in the MRW super-field, a special case value is used for the length field to indicate that the MRW super-field holds a single layer 2 PDU sequence number for a single layer 2 SDU that is to be discarded and that extends beyond a transmitting window of the transmitter; transmitting the MRW super-field to the receiver; extracting the initial sequence number from the MRW super-field according to an extracting algorithm corresponding to the packing algorithm to enable identification of the initial sequence number; assuming layer 2 PDU sequence numbers within MRW super-field are all sequentially on or after the initial sequence number when determining the sequential ordering of layer 2 PDUs for discarding each layer 2 SDUs; and assuming the layer 2 PDU sequence number to be sequentially on or after a starting point sequence number of a receiving window of the receiver when the length field holds the special case value.