Patent ID: 6987730

Claim:
A data transmission apparatus for transmitting data packets, said transmission apparatus comprising: a transmitter operable to transmit the data packets, said transmitter comprising a priority assignment part, a packet transmitter, a reception state receiver and a packet retransmitter; and a receiver operable to receive the data packets, said receiver comprising a packet receiver, a reception state transmitter and a retransmission request transmitter, wherein said priority assignment part is operable to assign priorities to the data packets, wherein said packet transmitter is operable to transmit a priority-assigned packet, wherein said reception state receiver is operable to receive information related to a packet reception state of said receiver, wherein said packet retransmitter is operable to perform packet retransmission in response to a retransmission request from said receiver, wherein said packet receiver is operable to receive the priority-assigned packet provided by said packet transmitter and to detect packet loss information, wherein said reception state transmitter is operable to transmit the information related to the packet reception state, which is based on the packet loss information detected by said packet receiver, wherein said retransmission request transmitter is operable to transmit the retransmission request if any packet of high priority is detected as having been lost, and wherein said priority assignment part is further operable to change a manner of assigning priorities to the data packets so that a number of times a high priority is assigned is decreased when the packet reception state does not meet a parameter, and the number of times the high priority is assigned is increased when the packet reception state meets the parameter.