Patent ID: 7519084

Claim:
A method of transmitting data packets from a transmitter to a receiver, the transmitter and the receiver including a stack of communication protocol layers and using a Segmentation and Re-assembly mechanism (SAR), the method comprising the steps of: segmenting parent data packets of an upper layer of the protocol layers by the SAR mechanism at the transmitter into at least two consecutive segments having a shorter length than the parent data packets; generating a two-level segment numbering based on said segmenting by the SAR mechanism, the two-level segment numbering include a parent data packet sequence number configured to identify the parent data packet for each segment, and a segment sequence number configured to identify a rank of the segment within the parent data packet; sending forward signaling messages from the transmitter to the receiver, and sending feedback signaling messages from the receiver to the transmitter, at least one of the forward and the feedback signaling messages including the two-level segment numbering, the forward signaling message including a discard request forward signaling message; reconstructing the parent data packets of the upper layer by concatenating received segments at the receiver by using the two-level segment numbering of said forward signaling message; selective retransmitting segments detected by an error recovery mechanism, by using at least one of forward signaling message and feedback signaling message; discarding segments based on the discard request forward signaling message, the discard request forward signaling message including a parent data packet sequence number; and delivering to the upper layer a parent data packet of a determined parent data sequence number when all the segments of the parent data packet have been correctly received and reconstructed.