Patent ID: 7542443

Claim:
A method of updating a receive window in a receiver in a communication system in which radio link control blocks are transmitted according to at least one of an unacknowledged transmission mode and a non-persistent transmission mode, wherein each block has a respective block number and an encoded header that enables the block number to be determined, and the block numbers of blocks transmitted to the receiver have a sequence that is known to the receiver, the method executed by the receiver comprising the steps of: comparing the block number of a received block to a receive window; if the block number of the received block is outside the receive window, discarding the received block; if the block number of the received block is inside the receive window, retaining the received block; and determining an updated receive window, wherein the updated receive window has a reduced size that excludes received blocks having block numbers that are not permitted according to the sequence; wherein the determining step includes determining a MaxN 0 parameter for the received block based on whether the block's header is judged to have been decoded correctly and whether the block number is inside the receive window; the size of the receive window is reduced based on the MaxN 0 parameter; if the block's header is judged as correctly decoded and if the block number is inside the receive window, the MaxN 0 parameter is set equal to an N 0 parameter that is based on a the block number of a previously received block; and if the block's header is judged as incorrectly decoded or if the block number is outside the receive window, the MaxN 0 parameter is determined by incrementing the MaxN 0 parameter by a predetermined amount according to the sequence.