Wi-Fi

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

Table of contents

1 Wifi vs. cellular 2 Commercial Wi-Fi 3 Advantages of Wi-Fi 4 Disadvantages of Wi-Fi 5 Trademark 6 Unintended use by outsiders 7 See also 8 External links

Wifi 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) and the narrowness of the available spectrum. Despite such problems, companies like SocketIP and Symbol Technologies are offering telephony platforms (Central Office replacements and terminalss (phones)) that use Wi-Fi transport.

Commercial Wi-Fi

Areas with Wi-Fi service are called "hotspots" and can either be free or for a fee. There may be metered access or with a pass for e.g. 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 US. Pacific Century Cyber Works has a similar arrangement with Pacific Coffee in Hong Kong. Other large hotspot providers in the US 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 in hotels, malls and government offices.

Compare Internet cafe.

Advantages of Wi-Fi

• Many reliable and bug-free WiFi products on the market
• Competition amongst vendors has lowered prices considerably since their inception
• While connected on a WiFi network, it is possible to move about without breaking the network connection.

Disadvantages of Wi-Fi

• The 802.11b and 802.11g flavors of Wi-Fi use the 2.4 Ghz spectrum, which is crowded with other devices such as Bluetooth, microwave ovens, cordless phones, or video sender devices, among many others. This may cause a degradation in performance. Other devices which use microwave frequencies such as certain types of cell phones can also cause degradation in performance.
• Power consumption is fairly high compared to other standards, making battery life and heat a concern.
• Not always configured properly by user. Commonly uses WEP (Wired Equivalent Privacy) protocol for protection, though has been shown to be easily breakable. Newer wireless solutions are slowly providing support for the superior WPA (Wi-Fi Protected Access) protocol, though many systems still employ WEP.

Trademark

Wi-Fi is a trademark of the Wi-Fi Alliance (formerly the Wireless Ethernet Compatibility Alliance), the trade organization that defines the Wi-Fi 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.

See also

• OSGi Alliance

External links

• Wi-Fi Alliance
• Wi-Fi technical specifications (in English and French)
• Wireless LAN security resources and whitepapers
• List hotspots in specified country or city
• Wi-Fi technology