Control method for selective repeat retransmission protocols

摘要

The present invention provides a highly efficient retransmission control method in which the order of data is prevented from being changed by one revolution of a modulo without adding extra overhead. The transmitting side continues to continuously transmit frames assigned frame numbers circulating by a modulo M to the receiving side. The receiving side returns, upon detecting an error in the received frame, a reject provided with the frame number of the frame. The transmitting side retransmits the frame to the receiving side in response to the reject. In a case where such retransmission control is carried out, the maximum number of times Nr of return of the returnable reject to the same frame is previously determined. The receiving side discontinues the return of the reject to the same frame until the number of times of the return exceeds the maximum number of times Nr. Consequently, the return of the reject to the same frame can be discontinued before the modulo of the frame number revolves once. As a result, it is possible to prevent the order of data from being changed by one revolution of the modulo.