This paper suggests and analyzes the performance of a new Wireless ATM Adaptive Error Control System, which can be used in wireless ATM networks to improve quality of service in keeping the cell loss under a certain predefined limit and reducing the average delay of cell encoding.The new system is based on multi-level Forward Error Correction (FEC), and specifically the Bose-Chaudhuri-Hocqenghem (BCH) code [3], which has multiple error correcting capability and a wide class of block codes, to overcome random errors.Realistic error patterns caused by multi-path turbulent fading are analytically approximated and applied to the suggested system. Performance analysis for the new system showed that it improves cell loss rate to a value of less than 10 -9 in case of non fading and it keeps the average cell loss close to a reasonable value (approximately 10 -7 ) in case of fading, while maintaining an average encoding delay considerably less than the delay of a system using a fixed BCH correction capability.