QCN
(Q)ualcomm (C)alibration (N)etwork file
*.QCN - original qualcomm format file, compatible with QPST (qualcomm original programm).
Z3X SW use original format of file, this mean - you can read QCN by QPST and then write via Z3X, and QCN readed by z3x you can write via QPST.