Definition

frequency-shift keying (FSK)

See also phase-shift keying (PSK).

Frequency-shift keying (FSK) is a method of transmitting digital signals. The two binary states, logic 0 (low) and 1 (high), are each represented by an analog waveform. Logic 0 is represented by a wave at a specific frequency, and logic 1 is represented by a wave at a different frequency. A modem converts the binary data from a computer to FSK for transmission over telephone lines, cables, optical fiber, or wireless media. The modem also converts incoming FSK signals to digital low and high states, which the computer can "understand."

fsk.gif (2423 bytes)

The FSK mode was introduced for use with mechanical teleprinters in the mid-1900s. The standard speed of those machines was 45 baud, equivalent to about 45 bits per second. When personal computers became common and networks came into being, this signaling speed was tedious. Transmission of large text documents and programs took hours; image transfer was unknown. During the 1970s, engineers began to develop modems that ran at faster speeds, and the quest for ever-greater bandwidth has continued ever since. Today, a standard telephone modem operates at thousands of bits per second. Cable and wireless modems work at more than 1,000,000 bps (one megabit per second or 1 Mbps), and optical fiber modems function at many Mbps. But the basic principle of FSK has not changed in more than half a century.

This was last updated in March 2010

Dig Deeper on Telecommunication networking

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

Dateiendungen und Dateiformate

Gesponsert von:

SearchUnifiedCommunications

SearchMobileComputing

SearchDataCenter

  • How do I size a UPS unit?

    Your data center UPS sizing needs are dependent on a variety of factors. Develop configurations and determine the estimated UPS ...

  • How to enhance FTP server security

    If you still use FTP servers in your organization, use IP address whitelists, login restrictions and data encryption -- and just ...

  • 3 ways to approach cloud bursting

    With different cloud bursting techniques and tools from Amazon, Zerto, VMware and Oracle, admins can bolster cloud connections ...

SearchITChannel

Close