What is Wi-Fi

What is it?

It is a communication technology that makes use of radio waves in order to connect to a local area network. It is also widely used to connect to the internet from a laptop or smart phone whilst out and about.

How does it work?

Each Wi-Fi enabled device searches for a Wi-Fi base station located nearby. If it finds a network, you can connect to it by providing the correct password. Some networks are not password protected and your device will connect immediately. The access points are called 'Hot spots'.

The Wi-Fi base station usually takes the form of a network router / ADSL modem. This router is often connected directly to the internet on a standard ADSL telephone line. This is why you are able to connect to the internet using Wi-Fi.


What happens to make a connection?

It works a bit like a television. The radio bandwidth available to the base station is divided into a number of 'channels'. Typically 13 channels. When a device comes along that wants to connect, the base station allocates a spare channel for it to use. More than one device can use the same channel, but it will tend to slow down the connection.

Of course, both the base station and the Wi-Fi device must share the same way of talking to one another. This is called the 'protocol'. A common wireless protocol you will find is the 802.11g standard but there are many others as well.


What does Wi-Fi stand for?

The word Wi-Fi is actually a trade name owned by the Wi-Fi alliance. The alliance is a group of about 300 companies from around the world. They work together to make sure that all 'Wi-Fi' enabled devices are compatible with one another. These days most laptops have Wi-Fi built into them.

How fast can it transmit data?

The maximum speed of a wireless network using the 802.11g standard is 54 Mb/s but in reality the speeds are much lower than this. Compare this to a hard-wired Gigabit network that can transmit 1000 Mb/s. However, even that slower speed is fine for most uses. Speed is mostly influenced by the strength of the radio signal - the weaker it is the slower the speed.

Are there problems with it?

Yes. The main concern is security. After all you are broadcasting your network data over radio waves and these are easily picked up by other devices within range. Originally, Wi-Fi networks were virtually open to anyone. Some people made a hobby of driving around looking for open networks.

Security is now much better, with many wireless networks set up with proper encryption and passwords. There are still plenty of free hotspots around, but they are usually deliberately left open for customers \ people to use.

Another problem is that it can only connect a limited number of devices as they all have to share a limited number of radio channels. So it is best to use hard-wired cabling for the main company network with some additional Wi-Fi connections available for meeting rooms and so on.

What about the future?

Some cities are now making it an objective to have complete Wi-Fi coverage. For instance London is planning to have city-wide coverage by the time of the Olympics in 2012. This will require hundreds of hot spots to be in place.




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