Wi-Fi Network

Wi-Fi the trade name for the popular wireless technology used in home networks, mobile phones, video games and other electronic devices that require some form of wireless networking capability. In particular, it covers the various IEEE 802.11 technologies (including 802.11a, 802.11b, 802.11g, and 802.11n).

Wi-Fi technologies are supported by nearly every modern personal computer operating system, most advanced game consels and laptops, and many printers and other periphirals.

Purpose

The purpose of Wi-Fi is to provide wireless access to digital content. This content may include applications, audio and visual media, Internet connectivity, or other data. Wi-Fi generally makes access to information easier, as it can eliminate some of the physical restraints of wiring; this can be especially true for mobile devices.

Uses

A Wi-Fi enabled device such as a PC, game console, mobile phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access printers — called a hotspot — can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. Wi-Fi technology has served to set up mesh networks, for example, in London.Both architectures can operate in community networks.

In addition to restricted use in homes and offices, Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers. Organizations and businesses such as airports, hotels and restaurants often provide free hotspots to attract or assist clients. Enthusiasts or authorities who wish to provide services or even to promote business in a given area sometimes provide free Wi-Fi access. Metropolitan-wide Wi-Fi has more than 300 projects in process.There were 879 Wi-Fi based Wireless Internet Service Provider in the Czech Republic as of May 2008.

Wi-Fi also allows connectivity in peer to peer mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications.

Advantages

Wi-Fi allows local area networks(LANs) to be deployed without cabling for client devices, typically reducing the costs of network deployment and expansion. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs.

Wireless network adapters are now built into most laptops. The price of chipsets for Wi-Fi continues to drop, making it an economical networking option included in even more devices. Wi-Fi has become widespread in corporate infrastructures.

Different competitive brands of access points and client network interfaces are inter-operable at a basic level of service. Products designated as "Wi-Fi Certified" by the Wi-Fi Alliance are backwards compatible. Wi-Fi is a global set of standards. Unlike mobile telephones, any standard Wi-Fi device will work anywhere in the world.

Wi-Fi is widely available in more than 220,000 public hotspots and tens of millions of homes and corporate and university campuses worldwide. WPA is not easily cracked if strong passwords are used and WPA2 encryption has no known weaknesses. New protocols for Quality of Service (WMM) make Wi-Fi more suitable for latency-sensitive applications (such as voice and video), and power saving mechanisms (WMM Power Save) improve battery operation.

Limitations

Spectrum assignments and operational limitations are not consistent worldwide. Most of Europe allows for an additional 2 channels beyond those permitted in the U.S. for the 2.4 GHz band. (1–13 vs. 1–11); Japan has one more on top of that (1–14). Europe, as of 2007, was essentially homogeneous in this respect. A very confusing aspect is the fact that a Wi-Fi signal actually occupies five channels in the 2.4 GHz band resulting in only three non-overlapped channels in the U.S.: 1, 6, 11, and three or four in Europe: 1, 5, 9, 13 can be used if all the equipment on a specific area can be guaranteed not to use 802.11b at all, even as fallback or beacon.