Patent ID: 6738379
Filing Date: 2004-05-18
Classification: H04L

Abstract:
A method of preserving data packet sequencing when a plurality of data packets are transmitted over a plurality of data transmission paths between a sending node and a receiving node in a radio telecommunications network, said method comprising the steps of:sequentially numbering the data packets at the sending node; sequentially transmitting the packets in a sequence from the sending node over the plurality of data transmissions paths; receiving the sequence of data packets at the receiving node; passing the received data packets directly to a receiving application if the received data packets have sequential packet numbers; and reconstructing the data packets into the transmitted sequence if the received data packets do not have sequential packet numbers, said reconstructing step including the steps of: storing a first data packet received out of sequence in a reconstruction buffer having a finite storage space with a beginning and an end; storing additional received data packets in the buffer in increasing numerical order from the beginning of the buffer; determining whether two or more stored data packets at the beginning of the buffer have sequential packet numbers; sending the two or more stored data packets with sequential packet numbers from the buffer to the receiving application; starting a packet timer, T1, at the receiving node when the first out-of-sequence data packet is received, T1 timing the longest permissible transfer time of a single packet through the network, and T1 being reset each time a sequential data packet at the beginning of the buffer is received, or the buffer is filled; determining whether or not T1 expires before a sequential data packet at the beginning of the buffer is received or the buffer is filled; and passing any sequential data packets stored in the buffer to the receiving application if T1 expires before a sequential data packet at the beginning of the buffer is received, or if the buffer is filled.