Wi-Fi stands for Wireless Fidelity. Wi-Fi is based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11
standards Wi-Fi has become the defacto standard for last feet broadband connectivity in homes,
offices, and public hotspot locations. systems can typically provide a coverage
range of only about 1,000 feet from the access point.
Wi-Fi offers remarkably higher peak
data rates than do 3G systems, primarily since it operates over a larger 20MHz
bandwidth, but Wi-Fi systems are not designed to support high-speed mobility.
One significant advantage of Wi-Fi
over WiMAX and 3G is the wide availability of terminal devices. A vast majority
of laptops shipped today have a built-in Wi-Fi interface. Wi-Fi interfaces are
now also being built into a variety of devices, including personal data
assistants (PDAs), cordless phones, cellular phones, cameras, and media
players.
The WiFi standards define a fixed
channel bandwidth of 25 MHz for 802.11b and 20 MHz for either 802.11a or g
networks.
All Wi-Fi networks are contention-based TDD systems, where the access point and the mobile stations all vie for use of the same channel. Because of the shared media operation, all Wi-Fi networks are half duplex.
There are equipment vendors who market Wi-Fi mesh configurations, but those implementations incorporate technologies that are not defined in the standards.
Range:
Wi-Fi networks have limited range. A typical wireless access point using 802.11b or 802.11g with a stock antenna might have a range of 35 m (115 ft) indoors and 100 m (330 ft) outdoors
Range:
Wi-Fi networks have limited range. A typical wireless access point using 802.11b or 802.11g with a stock antenna might have a range of 35 m (115 ft) indoors and 100 m (330 ft) outdoors