Wi-Fi
Wireless Fidelity

Official Wi-Fi logo

Wi-Fiwas originally a brand licensed by the Wi-Fi Alliance to describethe embedded technology of wirelesslocal area networks (WLAN) based on the IEEE 802.11standard. As of 2007, common use of the term Wi-Fi has broadened todescribe the generic wireless interface of mobile computing devices,such as laptops in LANs.^{[citation needed]}The term Wi-Fi was chosen as a play on the term "Hi-Fi", and is oftenthought to be an abbreviation for wirelessfidelity, though the Wi-Fi Alliance no longerrecognizes such. Wi-Fi and the Wi-FiCERTIFIED logo are registered trademarks of the Wi-Fi Alliance,the trade organization that tests and certifies equipment compliancewith the 802.11x standards.

Commonuses for Wi-Fi include Internetand VoIPphone access, gaming, and networkconnectivity for consumer electronicssuch as televisions, DVD players, and digital cameras. In spiteof media reports about possible health risksfrom Wi-Fi, scientific studies have failed to show a causal effect.^[1][2]

Wi-Finetworks use radio technologies called IEEE 802.11. Thesetechnologies have gone through several generations since theirinception in 1997. Wi-Fi is supported to different extents under Microsoft Windows, Apple Inc. MacOS and open source Unixand Linux operating systems.

Uses

Aperson with a Wi-Fi enabled device such as a PC, cell phone or PDA can connectto the Internet when in proximity of an access point. The regioncovered by one or several access points is called a hotspot. Hotspots canrange from a single room to many square miles of overlapping hotspots.Wi-Fi can also be used to create a mesh network. Botharchitectures are used in community networks.^{[citation needed]}

Wi-Fialso allows connectivity in peer-to-peer (wireless ad-hoc network)mode, which enables devices to connect directly with each other. Thisconnectivity mode is useful in consumer electronics and gamingapplications.

Whenthe technology was first commercialized there were manyproblems because consumers could not be sure that products fromdifferent vendors would work together. The Wi-Fi Alliance began as acommunity to solve this issue so as to address the needs of the enduser and allow the technology to mature. The Alliance created thebranding Wi-Fi CERTIFIED to show consumers thatproducts are interoperable with otherproducts displaying the same branding.

HomeWi-Fi clients come in many shapes and sizes, from stationary PCs to digital cameras. The trendas of 2007 is to incorporate wireless into every electronic devicewhere mobility is desired.^{[citation needed]}

Wi-Fidevices in home or consumer-type environments canconnect via a broadband Internet connection into a single router whichcan serve both wired and wireless clients. They can also use ad-hoc modefor client to client connections, and be built into non-computerdevices to enable wireless connectivity to the Internet.

Businessand industrial Wi-Fi has become ubiquitous as of 2007. Inbusiness environments, increasing the number of Wi-Fi access pointsprovides redundancy, support for fast roaming and increase overallnetwork capacity by using more channels or creating smaller cells.Wi-Fi enables wireless voice applications (VoWLAN or WVOIP). Over theyears, Wi-Fi implementations have moved toward 'thin' access points,with more of the network intelligence housed in a centralized networkappliance, relegating individual Access Points to be simply 'dumb'radios. Outdoor applications may utilize true mesh topologies. As of 2007,Wi-Fi installations can provide a proactive, self-managed network thatfunctions as a security gateway, firewall,DHCPserver, intrusion detection system,and a myriad of other features not previously considered relevant to awireless network.^{[citation needed]}

Themost publicly visible use of Wi-Fi is at hotspots, including:

• Free Wi-Fi at venues like Panera Bread, It's a Grind Coffee House,select hotels, and over 100,000 locations in the USA has been growingin popularity. According to a door-to-door survey in SanJose, CA, the number of venues and users is growing fast.^{[citation needed]}
• Paid Wi-Fi at venues like Starbucks, McDonalds, and at hotels.This trend is growing rapidly at venues that require a higher rate ofcustomer churn, such as sit-down restaurants.^{[citation needed]}
• Metropolitan-wide WiFi (Mu-Fi)already has more than 300 projects in process.^[3]