802.11

(redirected from WiFi network)

802.11

Commonly known as "Wi-Fi," the IEEE 802.11 standards provide the wireless counterpart to Ethernet, and the Wi-Fi Alliance certifies products. All versions use OFDM encoding except for the earlier 802.11b, which uses DSSS (see OFDM and spread spectrum). For details about each standard, see table below and 802.11 versions.

Infrastructure and Ad Hoc Modes
In "infrastructure" mode, Wi-Fi devices transmit to an "access point" (base station), which may be a stand-alone unit or built into a wireless router. In "ad hoc" mode, two wireless devices communicate peer-to-peer without an access point in between. Another direct connection mode is also available (see Wi-Fi Direct).

Throughput Varies
Speed is distance dependent. The farther away the device from the base station, the lower the speed. Also, the actual throughput is generally half of the rated speed because 802.11 uses collision "avoidance" (see CSMA/CA) rather than Ethernet's collision "detection" method (see CSMA/CD). For example, a rated 54 Mbps may yield 27 Mbps in real data throughput. For more about Wi-Fi networks, see wireless LAN and Wi-Fi. See Wi-Fi hotspot, 802.11 timeline, wireless router, ISM band, 802.16 and 802.15.

    802.11 SPECIFICATIONS              Max    Indoor  Channel    Bands   Speed   Range*   Width    (GHz)   (Mbps)  (ft)     (MHz)11ac      5  433***  230   20/40/80/160
 11n  2.4, 5  150**   230   20/40
 11a       5   54      95   20
 11g  2.4      54     170   20
 11b  2.4      11     150   20

   * = Up to 4x farther outdoors.
  ** = Per antenna at 40 MHz channels.
 *** = Per antenna at 80 MHz channels.


Wi-Fi Access Points
Wi-Fi devices transmit to central base stations called "access points" (APs), such as these ceiling-mounted and desktop examples (bottom). The circuitry in an access point is also built into a wireless router.


Wi-Fi Access Points
Wi-Fi devices transmit to central base stations called "access points" (APs), such as these ceiling-mounted and desktop examples (bottom). The circuitry in an access point is also built into a wireless router.







Wi-Fi Adapters
The adapter (top) adds Wi-Fi to any computer via USB, while the card on the bottom plugs into a PCI slot inside a desktop computer. (Images courtesy of D-Link Corporation and TP-LINK Technologies Co., Ltd.)
References in periodicals archive ?
Tenders are invited for WiFi Network Equipment: CIPA Compliant Public WiFi Network Turnkey Solution
CirrusWorks and HarborLink help Hope Hotel boosts Internet performance on busy WiFi network by deploying an innovative new technology called "The Governor(TM)"
Freewheel customers will have automatic access to the Optimum WiFi network of 1.
com/global-en/products/tablets/xperia-z3-tablet-compact/features/#gaming) Remote Play over the internet, but still recommend users to have both the console and remote connected to the same WiFi network and users should have fast internet connection for better gaming experience.
Hughes said in-store WiFi networks often hobble critical business traffic such as POS transactions and VoIP conversations when sharing the same WiFi network with unpredictable guest WiFi traffic.
The public wifi network run by Cardiff Council, called the CardiffFreeZone,w covers the Cardiff Story Museum.
According to the research, nearly half of all Britons using public WiFi hotspots have no idea whether the WiFi network is secure or open when they connect to it via their smart-phones, tablets or laptops.
The need to build a complementary WiFi network to their 3G/4G mobile networks and offload congested cellular networks for premium connections and very critical connections is starting to explode," experts said.
BONN & MADRID -- Fon, the global WiFi network and Deutsche Telekom, the leading German telco, announced a partnership to build Germany's largest WiFi network, which will launch in the summer under the name WLAN TO GO.
WORLDWIDE COMPUTER PRODUCTS NEWS-March 4, 2013-Deutsche Telekom and Fon collaborate to create WiFi network in Germany(C)1995-2013 M2 COMMUNICATIONS http://www.
London, Aug 29 ( ANI ): Tech giant Apple is gearing up for the launch of a new 'AirPlay Direct' technology, which would allow wireless music playback without the need of a WiFi network.
However, most of us are not aware the online identity risks inherent in using a public WiFi network.