Network node (100), mobile terminal (200), method and computer program wherein a network node (100) or a mobile terminal (200) comprise a transceiver (110, 210) which is adapted for transmitting data frames comprising data transport blocks and redundancy information, further comprising a processing unit (120, 240) receiving at least one parameter value indicative of the quality of a radio channel and at least one message indicative of an actual block error rate for the transmitted data frame, wherein the processing unit (120, 240) determines an expected block error probability for each transmitted data frame and adjusts the at least one received parameter value based on the difference between an at least one previously calculated block error probability and the actual block error rate.