Frequency Shift Keying
(FSK) The use of {frequency modulation} to
transmit digital data, i.e. two different {carrier}
frequencies are used to represent zero and one.
FSK was originally used to transmit {teleprinter} messages by
radio ({RTTY}) but can be used for most other types of radio
and land-line digital telegraphy. More than two frequencies
can be used to increase transmission rates.
(1997-07-14)