Internet access

Internet access
A roof-mounted Wi-Fi antennaA Wi-Fi enabled device such as a personal computer, video game console, smartphone or digital audio player can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more (interconnected) access points — called hotspots — can comprise an area as small as a few rooms or as large as many square miles. Coverage in the larger area may depend on a group of access points with overlapping coverage. Wi-Fi technology has been used in wireless mesh networks, for example, in London, UK.[15]

In addition to private use in homes and offices, Wi-Fi can provide public access at Wi-Fi hotspots provided either free-of-charge or to subscribers to various commercial services. Organizations and businesses - such as those running airports, hotels and restaurants - often provide free-use hotspots to attract or assist clients. Enthusiasts or authorities who wish to provide services or even to promote business in selected areas sometimes provide free Wi-Fi access. As of 2008[update] more than 300 metropolitan-wide Wi-Fi (Muni-Fi) projects had started.[16] As of 2010[update] the Czech Republic had 1150 Wi-Fi based wireless Internet service providers.[17][18]

Routers that incorporate a digital subscriber line modem or a cable modem and a Wi-Fi access point, often set up in homes and other premises, can provide Internet access and internetworking to all devices connected (wirelessly or by cable) to them. With the emergence of MiFi and WiBro (a portable Wi-Fi router) people can easily create their own Wi-Fi hotspots that connect to Internet via cellular networks. Now iPhone, Android or Symbian phones can create wireless connections.[19]

One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router. Wi-Fi also connects places that would traditionally not have network access, for example kitchens and garden sheds.

[edit] City-wide Wi-FiFurther information: Municipal wireless network

An outdoor Wi-Fi access point in Minneapolis
An outdoor Wi-Fi access point in TorontoIn the early 2000s, many cities around the world announced plans for city-wide Wi-Fi networks. This proved to be much more difficult than their promoters initially envisioned with the result that most of these projects were either canceled or placed on indefinite hold. A few were successful, for example in 2005, Sunnyvale, California became the first city in the United States to offer city-wide free Wi-Fi,[20] and Minneapolis has generated $1.2 million profit annually for their provider.[21]

In May, 2010, London, UK Mayor Boris Johnson pledged London-wide Wi-Fi by 2012.[22] Both the City of London, UK[23] and Islington[24] already have extensive outdoor Wi-Fi coverage.

[edit] Campus-wide Wi-FiCarnegie Mellon University built the first wireless Internet network in the world at their Pittsburgh campus in 1994,[25] long before Wi-Fi branding originated in 1999. Many traditional college campuses provide at least partial wireless Wi-Fi Internet coverage.

Drexel University in Philadelphia made history by becoming the United States' first major university to offer completely wireless Internet access across the entire campus in 2000.[26]

[edit] Direct computer-to-computer communicationsWi-Fi also allows communications directly from one computer to another without the involvement of an access point. This is called the ad hoc mode of Wi-Fi transmission. This wireless ad hoc network mode has proven popular with multiplayer handheld game consoles, such as the Nintendo DS, digital cameras, and other consumer electronics devices.

Similarly, the Wi-Fi Alliance promotes a specification called Wi-Fi Direct for file transfers and media sharing through a new discovery- and security-methodology.[27] Wi-Fi Direct launched in October 2010.[28]

[edit] Future directionsAs of 2010[update] Wi-Fi technology has spread widely within business and industrial sites. In business environments, just like other environments, increasing the number of Wi-Fi access points provides network redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells. Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP). Over the years, Wi-Fi implementations have moved toward "thin" access points, with more of the network intelligence housed in a centralized network appliance, relegating individual access points to the role of "dumb" transceivers. Outdoor applications may utilize mesh topologies.