SolveYourProblem
eLearning Series
Wireless Networking
How
Do Wireless Networks Work?
by Jeff Cohen
Wireless networks
work using radio waves instead of wires to transmit data
between computers. That's the simple version. If you're curious
to know what's going on in more detail, it's all explained
below.
Ones and
Zeros
I'm sure you know
that computers transmit data digitally, using binary (ones
and zeros). This is a way of communicating that translates
very well to radio waves, since the computer can transmit
ones and zeros as different kinds of beep. These beeps are
so fast that they're outside a human's hearing range. Radio
waves that you can't hear are, in fact, all around you all
the time. That doesn't stop a computer from using them, though.
Morse
Code
The way it works
is a lot like Morse code. You probably already know that
Morse code is a way of representing the alphabet so that
it can be transmitted over radio using a dot (short beep)
and a dash (long dash). It was used manually for years, and
became a great way of getting information from one place
to another with the invention of the telegraph. More importantly
for this example, though, it is a binary system, just like
a computer's ones and zeros.
You might think
of wireless networking, then, as being like Morse code for
computers. You plug a combined radio receiver and transmitter
in, and the computer is able to send out its equivalent of
dots and dashes (bits, in computer-speak) to get your data
from one place to another.
It’s All
About Frequencies
You might wonder
how a computer could possibly transmit enough bits to send
and receive data at the speed it does. After all, there must
be a limit on how much can be sent in a second before it
just becomes useless nonsense, right? Well, yes, but the
key to wireless networking is that it gets around this problem.
First of all,
wireless transmissions are sent at very high frequencies,
meaning that more data can be sent per second. Most wireless
connections use a frequency of 2.4 gigahertz (2.4 billion
cycles per second) -- a similar frequency to mobile phones
and microwave ovens. As you may know, though, a frequency
this high means that the wavelength must be very short, which
is why wireless networking only works over a limited area.
In addition, wireless
networks make use of a technique known as 'frequency hopping'.
They use dozens of frequencies in the range they are given,
and constantly switch between them. This makes wireless networks
more immune to interference from other radio signals than
they would be if they only transmitted on one frequency.
Access
Points
The final step
is when it comes to all the computers on a network sharing
Internet access. This is accomplished using a special piece
of wireless equipment called an access point. Access points
are more expensive than wireless cards for one computer,
as they contain radios that are capable of talking to around
100 computers at the same time, and sharing out access to
the Internet between them. Dedicated access points are only
really essential for larger networks. If you only have a
few computers, it is possible to use one of them as the access
point, or you could just get a wireless router.
They Understand
Each Other
That's all well
and good, then, but how does wireless equipment made by entirely
different companies manage to work together when this is
all so complicated? Well, the answer is that there are standards
that all wireless devices follow. These standards are technically
called the 802.11 standards, and are set by the IEEE (Institute
of Electrical and Electronics Engineers). It is thanks to
people sticking to their standards that wireless networking
is so easy and cheap to use today.
You Don't
Need to Worry
If all this talk
of frequencies has you a little worried, you don't need to
be -- wireless networking hardware and software handles all
of this automatically, without you needing to do a thing.
Don't think that you're going to have to tell one wireless
device what frequency another is using, because it's just
not going to happen, alright? Wireless networking, for all
its complicated workings, is really far more simple to use
than you'd ever expect.
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SolveYourProblem.com : 2007
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