An adaptive forward error correction system for mitigating interference and fading in RF data transmissions has a hub and subscriber stations transmitting and receiving forward error correction encoded data packets. The hub and subscriber stations count codewords and/or packets received with errors. The hub calculates a type of quality measure using the counts and compares this measure to quality thresholds. If an upper threshold is exceeded, the hub increases a size of transmitted active data fields and decreases a size of blank data fields. If a lower threshold is not met, the hub decreases a size of transmitted active data fields and increases a size of blank data fields. Similar changes by subscriber stations are directed by the hub. These changes are coordinated in headers associated with the packets or codewords, via a separate control channel or multi cast via a data stream used for transmitting the data packets.