24 Feb 2008 12:33:29 | Ron King
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 Author :
Ron King is a full-time researcher, writer, and web developer.
Visit http://www.havewireless.com to learn more.