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Wireless LANs
What is an IEEE 802.11b
Wireless LAN?
The new international standard
for 11 Mbps high speed Wireless LANs. A wireless LAN utilises radio instead of
cables, allowing users the freedom to roam around a building, whilst staying
connected to the network normally.
The radio signals penetrate
many barriers, including glass, cubicle walls and wooden walls. Even so,
802.11b Wireless LANs remain secure from unauthorized access thanks to multiple
layers of Wired Equivalent Privacy (WEP) which encrypts the wireless portion
with a 40-bit or 128-bit key. Additionally in order to gain access to the
network you must first know the network ID of an access point.
802.11b Wireless LANs operate
in the 2.4GHz ban and are therefore untroubled by interference from devices
such as mobile phones. However, microwave ovens and 2.4 GHz cordless phones may
cause some interference. To date, there is no conclusive evidence that the
radio waves in the 2.4 GHz range cause any health risk.
Each Access Point on the
Wireless LAN has a range of approximately 300 feet (100m) in a standard office
environment, although the range is dependent upon the environment.
Standard throughput is 11 Mbps,
with actual throughput being lower (in the same way as 10 Mbps Ethernet data
throughput is less than 10Mbps). The actual throughput of the 802.11b will be
slower than when using Ethernet, and will vary, depending upon file transfer
size, number of users and distance from the Access Point.
How do I assemble a Wireless
LAN?
It is simple to build a
Wireless LAN - a Single Access Point acts as a network Hub. Adaptor cards
installed in PCs communicate via the Access Point. A single Access Point will
support up to 63 users, but this is a shared environment, so the optimal number
may be lower. The optimal number of users on an Access Point will depend on the
applications being used. For connection to a normal LAN, the Access Point can
then be plugged into any Switch or Router.
To overcome compatibility
problems, a new standard called 'wi-fi' is soon to be introduced. All Wireless
LAN products bearing a 'wi-fi' logo will be guaranteed to be fully compatible
with each other.
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