Packet retransmission system, packet transmission device, packet reception device, packet retransmission method, packet transmission method and packet reception method

Abstract

In a packet retransmitting system for retransmitting a packet including a sequence number in a packet header, which is lost during packet communication, a transmitting equipment () includes a priority degree information attaching unit () for defining a plurality of priority degrees, setting an importance degree of each of the plurality of priority degrees for a packet, producing priority degree information by using the plurality of priority degrees, and attaching the priority degree information to the packet header included in the packet repeatedly for each of the plurality of packets, a transmitter () for transmitting the plurality of packets, and a retransmitting unit () for receiving a retransmission request packet and retransmitting a packet of which retransmission is requested in the retransmission request packet received. A receiving equipment () includes a receiving unit () for receiving the plurality of packets and a retransmission requesting unit () for extracting a plurality of sequence numbers and a plurality of priority degree information from the packet header, detecting lost packets based on the plurality of sequence numbers and the plurality of priority degree information extracted, detecting an important packet among the lost packets, and requesting retransmission of the packet.