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Wi-Fi (or Wi-fi, WiFi, Wifi, wifi), for "Wireless Fidelity", is a set of standards for wireless local area networks (WLAN) based on the IEEE 802.11 specifications (see also that article). Certified products can use the official Wi-Fi logo, which indicates that the product is interoperable with any other product also showing the logo.

Wi-Fi was intended to be used for wireless devices and LANs, but is now often also used for Internet access. It enables a person with a wireless-enabled computer or personal digital assistant (PDA) to connect to the Internet by moving within, for example, 15 meters of an access point, called "hotspot".

Table of contents
1 Wi-Fi vs. cellular
2 Commercial Wi-Fi
3 Advantages of Wi-Fi
4 Disadvantages of Wi-Fi
5 Wi-Fi and free software
6 Trademark
7 Unintended use by outsiders
8 See also
9 External links

Wi-Fi vs. cellular

Some argue that Wi-Fi and related consumer technologies hold the key to replacing cellular telephone networks such as GSM. Some obstacles to this happening in the near future are missing roaming and authentication features (see 802.1x, SIM cards and RADIUS), the narrowness of the available spectrum and the limited range of Wi-Fi. Despite such problems, companies like Zyxel, " class="external">http://www.zyxel.com/product/model.php?indexcate=1075688089&indexFlagvalue=1075687935--> SocketIP and Symbol Technologies are offering telephony platforms (Central Office replacements and terminalss (phones)) that use Wi-Fi transport.

The term 4G is occasionally used for Wi-Fi, the implication being that the bandwidth and capabilities offered are already greater than those promised by the 3G cellular telephone standards.

Commercial Wi-Fi

Areas with Wi-Fi service are called "hotspots" and can either be accessed for free or for a fee. There may be metered access or with a pass for, for example, a day, month or year, valid for one location or a whole chain. They are e.g. in coffee houses and airports around the world. T-Mobile provides hotspots in many Starbucks Coffee houses in the U.S. Pacific Century Cyber Works has a similar arrangement with Pacific Coffee in Hong Kong. Other large hotspot providers in the U.S. include Boingo, Wayport and iPass. Compared to cellular, however, even the combined coverage is currently still very patchy.

Sify, India's largest Internet service provider, has set up 120 wireless access points in Bangalore,India in hotels, malls and government offices.

Compare Internet cafe.

Advantages of Wi-Fi

Disadvantages of Wi-Fi

Wi-Fi and free software

As of version 2.6, little Wi-Fi hardware is supported by the Linux kernel. However, see the Adapters section below for pointers.


Wi-Fi is a trademark of the Wi-Fi Alliance (formerly the Wireless Ethernet Compatibility Alliance), the trade organization that tests and certifies equipment compliance with the 802.11x standards.

Unintended use by outsiders

Many business and residential users do not bother to protect their network, which can therefore also be used by people just outside the building, see warchalking and wardriving. Configuration is not hard, but requires both knowledge and effort.

See also

External links

Adapters with free, open drivers