 | What is Wi-Fi?
Wireless ethernet, otherwise known as Wi-Fi (for Wireless Fidelity) or 802.11, transmits network signals over spread spectrum radio. This allows the freedom to move around, for example with a laptop, while remaining connected to a network.
Two essential items are required -
1) An Access Point - this acts as the master device to which others will connect. There must always be at least one access point in a wireless network.
2) Wireless network adaptors - fitted to each computer that will use the wireless network. They come in various forms; PCI cards to fit inside desktop computers, PCMCIA (cardbus) cards to fit into laptops and USB adaptors which connect to a USB port on PCs, laptops and MACs. They are available to suit all operating systems including Windows, MAC OS and Linux.
Speeds and Standards.
All the speeds and standards start with 802.11 followed by a letter which denotes the speed and frequency band in use -
- The most common standard is 802.11b which supports speeds up to 11Mbps in the 2.4GHz band.
- A new standard called 802.11a, which supports speeds up to 54Mbps in the 5GHz band, appeared more recently. It has a relatively shorter range than 802.11b and is not interoperable with it, so 802.11a and 802.11b may well be replaced by...
- 802.11g which supports speeds up to 54Mbps in the 2.4GHz band. As this is the same band as the older 802.11b it is compatible with it and will interoperate with 802.11b equipment - albeit at 11Mbps.
WEP - Privacy and security issues.
Short for Wired Equivalent Privacy, it is a security protocol for wireless networks. WEP aims to provide security by encrypting data over radio waves so that it is protected as it is transmitted from one end point to another. In practice it allows the user to restrict access to the network and to ensure that no unauthorised access is available to private data and resources. Without it you can easily become a 'free hotspot' providing nearby users free access to your network and internet connection!
The real world - Range and throughput.
The reality of wireless throughput is likely to be only half of the speed 'stated on the box' with '11Mbps' 802.11b likely to achieve 4-5Mbps in practice and '54Mbps' 802.11a/g about 20-24Mbps.
The range of wireless networks in ideal conditions is 30m, although walls and other building fabric will certainly reduce this. Fitting better antennas to the Access Point and siting it high in the building (for example, in the loft of a house) will help to extend the range.
For much more information about Wi-Fi click here.
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