Facsimile machine having an error-correction mode and method for switching down a data transfer rate

摘要

A method for switching down a data transfer rate on a transmitter (sender) response to a request by a receiver for retransmission of data blocks comprising data errors in a facsimile machine has the following steps. If a transmission error occurs, the receiver sends a request from the receiver to the transmitter for retransmission of one or more data blocks in which one or more data errors have occurred. At the transmitter, the data transfer rate is switched down from a first data transfer rate to a second data transfer rate which is used for retransmitting the data block or data blocks in which one or more data errors have occurred. The switching-down process applied is controlled by calculating an expected value which indicates the possibility of occurrence of a data error when retransmitting the data block or the data blocks in which data errors have occurred, on the basis of a number of data blocks whose retransmission has been requested and a total number of data blocks which have been sent by the transmitter to the receiver.