| Wireless networks work using radio waves instead of | | | | As you might know, though, a frequency this high |
| wires to transmit data between computers. That's the | | | | means that the wavelength must be very short, which |
| simple version. If you're curious to know what's going | | | | is why wireless networking only works over a limited |
| on in more detail, then it's all explained in this article.I'm | | | | area.In addition, wireless networks make use of a |
| sure you know that computers transmit data digitally, | | | | technique known as 'frequency hopping'. They use |
| using binary: ones and zeros. This is a way of | | | | dozens of frequencies in the range they are given, and |
| communicating that translates very well to radio | | | | constantly switch between them. This makes wireless |
| waves, since the computer can transmit ones and | | | | networks more immune to interference from other |
| zeros as different kinds of beep. These beeps are so | | | | radio signals than they would be if they only |
| fast that they're outside a human's hearing range -- | | | | transmitted on one frequency.The final step is when it |
| radio waves that you can't hear are, in fact, all around | | | | comes to all the computers on a network sharing |
| you all the time.The way it works is a lot like Morse | | | | Internet access. This is done using a special piece of |
| code. You probably already know that Morse code is | | | | wireless equipment called an access point. Access |
| a way of representing the alphabet so that it can be | | | | points are more expensive than wireless cards for |
| transmitted over radio using a dot (short beep) and a | | | | one computer, as they contain radios that are capable |
| dash (long dash).More importantly for this example, | | | | of talking to around 100 computers at the same time, |
| though; it is a binary system, just like a computer's | | | | and sharing out access to the Internet between them. |
| ones and zeros. You might think of wireless | | | | Dedicated access points are only really essential for |
| networking, then, as being like Morse code for | | | | larger networks, though -- if you only have a few |
| computers. You plug a combined radio receiver and | | | | computers, it is possible to use one of them as the |
| transmitter in, and the computer is able to send out its | | | | access point, or you could just get a wireless |
| equivalent of dots and dashes (bits, in computer-speak) | | | | router.That's all well and good, then, but how does |
| to get your data from one place to another.You might | | | | wireless equipment made by entirely different |
| wonder how the computer could possibly transmit | | | | companies manage to work together when this is all |
| enough bits to send and receive data at the speed it | | | | so complicated? Well, the answer is that there are |
| does. After all, there must be a limit on how much can | | | | standards that all wireless devices follow. These |
| be sent in a second before it just becomes useless | | | | standards are technically called the 802.11 standards, |
| nonsense, right? Well, yes, but the key to wireless | | | | and are set by the IEEE (Institute of Electrical and |
| networking is that it gets around this problem.First of all, | | | | Electronics Engineers). It is thanks to people sticking to |
| wireless transmissions are sent at very high | | | | their standards that wireless networking is so easy |
| frequencies, meaning that more data can be sent per | | | | and cheap to use today.Gregg Hall is a consultant to |
| second. Most wireless connections use a frequency of | | | | the internet industry with over 12 years experience |
| 2.4 gigahertz (2.4 billion cycles per second) -- a similar | | | | online. |
| frequency to mobile phones and microwave ovens. | | | | |