WiFi

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=What is it?=

WiFi stands for Wireless Fidelity which is a type of internet connection for mobile device such as PDA(personal digital assistant), pocket computer, and cell phones. It requires hot spots where regions covered by signals from a router connected to a ISP. WiFi connection has main 3 types of standard: 802.11b and 802.11g standards transmit at 2.4 GHz; 802.11a standard transmit at 5 GHz which has faster data transforming speed.([|How stuff works], 2006) It often requires a wireless router connected with an ISP which sending radio signals about 100 feet away depends on the surrounding enviroment.

=History=

In 1991 invented by NCR Corporation/AT&T in Nieuwegein.

=Advantages=


 * Allow LANs connection without cables or wires.
 * Highly competible in many mobile devices.
 * Encryptions supported
 * Simple to use
 * Fastest wireless connection
 * Increase mobility

=Disadvantages=


 * Connection easy to be crowded with Bluetooth.
 * Limited range of approx 45m (150ft)
 * Require hot spots
 * Connection speed varies according to distance from hot spots
 * Signal cannot penatrate concrete or metals.

=Issues with WiFi Technology=

Interference
Devices using the 2.4GHz band, which includes 802.11b and 802.11g WiFi technologies, do not require a license when they operate below the 100 mW limit. As such, there are numerous other devices that operate on the same band, including cordless telephones, microwave ovens and Bluetooth devices. While newer 5.8GHz cordless phones help to partially remedy the issue, WiFi devices must still cope with interference from other devices, resulting in degraded signal strength ("Wi-Fi").

Security
In the majority of home and small office scenarios, wireless routers are often configured with only rudimentary WEP (Wired Equivalent Privacy) based security, or none at all ("Practical Wi-Fi"). As a result, it is very easy for other people to not only connect to the network, benefiting from free Internet access, but also to listen in on any traffic that may be flowing between clients and the hotspot. In 2005, the FBI gave a demonstration where they cracked a WiFi WEP key within 3 minutes using publicly available tools ("Wi-Fi"). While newer WPA (Wi-Fi Protected Access) based security provide better protection, widespread public adoption has been slow.

Health
In a recent announcement, Fred Gilbert, president of Lakehead University in Thunder Bay, Ontario, proclaimed that there would be no campus-wide WiFi network out of fear that the system's electromagnetic forces could pose a health risk. He cites studies that have shown possible links between electromagnetic forces and carcinogenetic occurrences in animals and people.

"Cancer fear curbs college's Wi-Fi." 

=City-wide Public WiFi Internet Access=

Some cities are now offering or considering offering free WiFi internet access throughout the whole city, giving anyone with a laptop in the city the freedom of always being connected for free. There are already cities in Canada that have this service set up (Fredricton, New Brunswick, for example), and many cities are considering offering the service. Hamilton, for example, is currently in the process of setting up a [|free WiFi internet connection] throughout the whole city.

=Works Cited=

How stuff works, 2006, located at http://computer.howstuffworks.com/wireless-network.htm

"Practical Wi-Fi security : realities of wireless security." 2006. __Hewlett-Packard Development Company__. 27 Feb 2006 .

"Wi-Fi." 27 Feb 2006. __Wikipedia, The Free Encyclopedia__. 27 Feb 2006 .