1) In computer networks, bandwidth is often used as a synonym for data
transfer rate - the amount of data that can be carried from one point to another
in a given time period (usually a second). This kind of bandwidth is usually
expressed in bits (of data) per second (bps). Occasionally, it's expressed as
bytes per second (Bps). A modem that works at 57,600 bps hastwice the bandwidth
of a modem that works at 28,800 bps. In general, a link with a high bandwidth is
one that may be able to carry enough information to sustain the succession of
images in a video presentation.
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| What is bandwidth ? |
It should be remembered that a real communications path usually consists of a
succession of links, each with its own bandwidth. If one of these is much slower
than the rest, it is said to be a bandwidth bottleneck.
2) In electronic communication, bandwidth is the width of the range (or band)
of frequencies that an electronic signal uses on a given transmission medium. In
this usage, bandwidth is expressed in terms of the difference between the
highest-frequency signal component and the lowest-frequency signal component.
Since the frequency of a signal is measured in hertz(the number of cycles of
change per second), a given bandwidth is the difference in hertz between the
highest frequency the signal uses and the lowest frequency it uses. A typical
voice signal has a bandwidth of approximately three kilohertz (3 kHz); an analog
television (TV) broadcast video signal has a bandwidth of six megahertz (6 MHz)
-- some 2,000 times as wide as the voice signal.
