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Wireless networks use radio
waves instead of wires to
transmit data between computers.
Here's how:
The Binary Code: 1s and 0s
It's well known that computers
transmit information digitally,
using binary code: ones and
zeros. This translates well to
radio waves, since those 1s and
0s can be represented by
different kinds of beeps. These
beeps are so fast that they're
outside the hearing range of
humans.
Morse Code: Dots And Dashes
It
works like Morse code, which is
a way to transmit the alphabet
over radio waves using dots
(short beeps) and dashes (long
beeps). Morse code was used
manually for years via telegraph
to get information from 1 place
to another very quickly. More
importantly for this example,
though, it is a binary system,
just as a computer system is.
Wireless networking, then, can
be thought of as a Morse code
for computers. You plug in a
combined radio receiver and
transmitter, and the computer is
able to send out its equivalent
of dots and dashes (bits, in
computer-speak) to get your data
from here to there.
Wavelengths And Frequencies
You might wonder how the
computer can send and receive
data at high speed without
becoming garbled nonsense. The
key to wireless networking is
how it gets around this problem.
First, wireless transmissions
are sent at very high
frequencies, which allows more
data to be sent per second. Most
wireless connections use a
frequency of 2.4 gigahertz (2.4
billion cycles per second) -- a
frequency similar to mobile
phones and microwave ovens.
However, this high frequency
produces a wavelength that is
very short, which is why
wireless networking is effective
only over short distances.
Wireless networks also use a
technique called "frequency
hopping." They use dozens of
frequencies, and constantly
switch among them. This makes
wireless networks more immune to
interference from other radio
signals than if they transmitted
on a single frequency.
Internet Access Points
The final step for a wireless
network is to provide internet
access for every computer on the
network. This is done by a
special piece of wireless
equipment called an access
point. An access point is more
expensive than a wireless card
for 1 computer, because it
contains radios capable of
communicating with around 100
computers, sharing internet
access among them. Dedicated
access points are necessary only
for larger networks. With only a
few computers, it is possible to
use 1 of them as the access
point, or to use a wireless
router.
Industry Standards
Wireless equipment from
different manufacturers can work
together to handle these complex
communications because there are
standards which guide the
production of all wireless
devices. These standards are
technically called the 802.11.
Because of industry compliance
with these standards, wireless
networking is both easy to use
and affordable today.
Wireless Is Simple To Use
If
all this talk of frequencies has
you worried -- relax. Wireless
networking hardware and software
handle all of this
automatically, without need for
user intervention. Wireless
networking, for all its
complicated ability, is far
simpler to use than you might
expect.
About the author:
Ron King is a full-time
researcher, writer, and web
developer. Visit http://www.havewireless.comfor
more info. Copyright 2005
Ron King. This article may be
reprinted if the resource box is
left intact. |
