Which listed communication service is classically associated with binary FSK…
2010
Which listed communication service is classically associated with binary FSK mark-and-space signalling?
Answer: B. Telegraphy — ConceptIn binary frequency-shift keying, the two binary symbols are represented by two distinct carrier frequencies. This mapping is naturally suited to…
- A.
Radio transmission
- B.
Telegraphy
- C.
Telephone
- D.
None of the above
Attempted by 5 students.
Show answer & explanation
Correct answer: B
Concept
In binary frequency-shift keying, the two binary symbols are represented by two distinct carrier frequencies. This mapping is naturally suited to discrete signalling systems in which mark and space states encode characters.
Application
Telegraphy sends coded characters as discrete mark and space states. FSK maps these states to two carrier frequencies, so telegraph signals can be transmitted and recovered reliably.
Contrast
Radio transmission is a broad propagation medium rather than one particular information service; many modulation schemes are used over radio.
Ordinary telephone service primarily carries speech, whose waveform varies continuously; FSK appears only in particular data-modem or signalling uses.
The “none” choice does not apply because telegraphy is one of the listed applications.
Cross-check
The historical use of FSK in voice-frequency and wireless telegraph systems agrees with the mark-and-space mapping. The answer is Telegraphy.