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, then it's
all explained in this article.
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.
All About Frequencies.
You might wonder, though, how the 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 might 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 done 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, though -- 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.
About the author:
John is a world recognized expert on wireless networking and
network management. His blog can be found at
http://www.wirelessinternetonline.com.
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