|
A measure of the range of
frequencies occupied by a data signal across a communications channel. The
greater the range of frequencies, the more data and thus information can be
transmitted in a given time. the term is normally used to refer to the
actual amount of information a communications connection can carry; its
capacity, in effect.
Generally, the bandwidth required for any given
purpose is directly related to the complexity of the task. It takes far more
bandwidth to download a full-page color picture in one second, for example,
than a page of plain text, a fact most regular web user now readily
appreciate. In an along systems, such as telephone and television, bandwidth
is measured in cycles as second, or hertz (Hz). A typical voice signal
occupies about 3 kilohertz (kHz), but a broadcast television signal occupies
about 6 megahertz (MHz), or 2,000 times as much. In digital systems,
bandwidth is measured in bits per second (bps) and multiples thereof :
kilobits per second (kbps), megabits per second (mbps) and gigabits per
second (gbps). There
is much confusion about exactly what the bandwidth of networks in widespread
use really means in terms of performance. For example, 56k modems can
transmit information at only half the 56,000bps that the name promises, and
10mbps Ethernet connections typically achieve only one-third of the
advertised speed. Nevertheless, size is everything in the internet world,
and both hardware manufacturers and Telco's are well aware of the marketing
pull of larger numbers. Increased bandwidth is the key to providing enhanced
web offering, such as video, audio and other rich media applications,
and large scale software distribution.
The process of building a communications
infrastructure that will support affordable high-speed internet access is
complex and expensive, and bandwidth providers have been slow to roll out
faster alternatives to their existing modem- based dial-up offerings.
Although many Isps now provide free (and slow) individual internet
access, anyone determined to own one of the fastest
t1 or t3 connections can expect to pay handsomely for the privilege.
Nevertheless, the widespread availability of new broadband
technologies such as adsl have made high-speed access much more
affordable for home users and businesses. Many advances have been made in
wireless communications, too, as telecoms companies introduce new services
such as gprs and the popularity of wi-fi networks grows. Only
one thing is certain : however fast your connection, content
providers will find a way to use every last byte of it. |
