Frequency-shift keying in which two telegraph signals are multiplexed and transmitted simultaneously by frequency shifting among four frequencies. ( 188 )
DOUBLE FREQUENCY SHIFT KEYING (DFSK)
Meaning of DOUBLE FREQUENCY SHIFT KEYING (DFSK) in English
Telecommunication standard terms English vocab. Английский словарь стандартных телекоммуникационных терминов. 2012