| 摘要 |
PURPOSE: A method for operating a packet retransmission group in consideration of packet error characteristics is provided to save Internet resources through an efficient group operation in a reliable multicast using many groups and to increase the performance of a sender and a receiver. CONSTITUTION: A sender prepares M numbers of data packets to send to a multicast group(Aorg) and sends them to the multicast group(Aorg)(301). The sender detects whether packet errors are generated locally or concentrically(302). In case that packet errors are concentrically generated in a regular area(spatial burst), the sender sets a multicast group(ARet) to Sj(304). In the event of normal condition, the sender sets the multicast group(ARet) to A(i mod N)(305). If packets errors are consecutively generated during a short time(temporal burst), the sender sets the multicast group(ARet) to Aorg(306). Afterwards, receiving NAK(i, Aorg) from the multicast group(Aorg), the sender retransmits a packet "i" through the multicast group(ARet)(307). In case that no more NAK(i, Ai) is received, the sender transmits ACK(i) to all the receivers of the multicast group(Aorg) and modifies the state of a group queue(Qi)(308). |
