IEEE 802.11 Standards

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Nowadays there are three organizations influencing WLAN standards. They are:

ITU-R  : is responsible for allocation of the RF bands
IEEE  : specifies how RF is modulated to transfer data
Wi-Fi Alliance  : improves the interoperability of wireless products among vendors

But the most popular type of wireless LAN today is based on the IEEE 802.11 standard, which is known informally as Wi-Fi.

* 802.11a: operates in the 5.7 GHz ISM band. Maximum transmission speed is 54Mbps and approximate wireless range is 25-75 feet indoors.
* 802.11b: operates in the 2.4 GHz ISM band. Maximum transmission speed is 11Mbps and approximate wireless range is 100-200 feet indoors.
* 802/11g: operates in the 2.4 GHz ISM band. Maximum transmission speed is 54Mbps and approximate wireless range is 100-200 feet indoors.
* 802.11n: operates in the 2.4 GHz ISM band. Maximum transmission speed is 300Mbps and approximate wireless range is 100-200 feet indoors.


ISM Band: The ISM (Industrial, Scientific and Medical) band, which is controlled by the FCC in the US, generally requires licensing for various spectrum use. To accommodate wireless LAN’s, the FCC has set aside bandwidth for unlicensed use including the 2.4Ghz spectrum where many WLAN products operate.

Wi-Fi: stands for Wireless Fidelity and is used to define any of the IEEE 802.11 wireless standards. The term Wi-Fi was created by the Wireless Ethernet Compatibility Alliance (WECA). Products certified as Wi-Fi compliant are interoperable with each other even if they are made by different manufacturers.

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