frequency-shift keying

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."

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.

Learn more about Network Administration

Do you have something to add to this definition? Let us know. Send your comments to techterms@whatis.com

FILE EXTENSION AND FILE FORMAT LIST File Extension and File Format List: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #

RELATED CONTENT Why is access denied to my Active Directory (AD) users and computers? Learn how to troubleshoot administrative domain access errors on your network in your Active Directory user list from our expert, Lindi Horton. What network loss testing tools/methods calculate dropped packets from a PC? Learn how to drop incoming packets on your network connection for testing purposes and the various emulators and methods available to do so, from our... Network user management Use this guide to learn how to manage problem users on your network -- from un-savvy Internet novices to toxic bosses -- to keep your network secure.

RELATED GLOSSARY TERMS Terms from Whatis.com − the technology online dictionary availability  (SearchNetworking.com) 1) In a telephone circuit, availability is the ratio between the time during which the circuit is operational and elapsed time. 2) In a network... carrier detect  (SearchNetworking.com)