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.
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