Method of preserving data packet sequencing

DETAILED DESCRIPTION In essence, the present invention augments the UDP protocol to attain similar characteristics as FR.
Since the UDP protocol does not enforce packet sequencing, the invention augments UDP by adding this capability.
As a result, the invention provides a protocol with automatic routing behavior and packet resequencing without requiring any supplemental control data transmissions or acknowledgments.
Thus, in one aspect, the present invention is a method of preserving the sequence of a plurality of data packets in a radio telecommunications network in which an Internet Protocol (IP) based protocol is utilized between a sending node and a receiving node whereby data packets at the receiving node are resequenced in the same order as sent by the sending node.
The method includes the steps of sequentially numbering the data packets at the sending node and sequentially transmitting the packets in a sequence from the sending node over a plurality of data transmission paths.
This is followed by the receiving of the sequence of data packets at the receiving node and passing the received data packets directly to a receiving application if the received data packets have sequential packet numbers.
The method reconstructs the data packets into the transmitted sequence if the received data packets do not have sequential packet numbers.
The method for reconstructing the data packets into the transmitted sequence includes the steps of storing a first out-of-sequence data packet in a reconstruction buffer, and starting a packet timer, T1, at the receiving node when the out-of-sequence packet is received.
T1 times the longest permissible transfer time of a single packet through the network.
Subsequently received data packets are also stored in the buffer.
If a received packet forms a sequence at the beginning of the buffer, the sequence is passed to the receiving application.
If there are any other out-of-sequence packets left in the buffer, T1 is restarted with a T1 value equal to the T1 default value minus the total time spent by the next out-of-sequence packet in the reconstruction buffer