IEEE 802.11

IEEE 802.11 is a suite of wireless communication protocols, also commonly known as WiFi, developed by the Institute of Electrical and Electronics Engineers  (IEEE). The most commonly used protocols are 802.11a, 802.11b, 802.11g and 802.11n. They differ in terms of the frequency at which they operate, the maximum speed achievable and the range they provide.

• 802.11a: This protocol operates at 5 GHz (Gigahertz – 1 billion cycles per second). It is strongly affected by rain and other environmental conditions, and so it is not commonly used for outdoor wireless applications. The maximum data rate attainable is 54 Mbps (megabits per second).
• 802.11b: This protocol operates at 2.4 GHz. This is the most commonly deployed standard for wireless communications. Most airports, malls and coffee shops use 802.11b. The maximum data rate is 11 Mbps.
• 802.11g: This protocol also operates at 2.4 GHz, and is completely interoperable with 802.11b. Thus, most hardware devices that work with 802.11b also work with 802.11g. The maximum data rate is 54 Mbps. This is the next most common standard, and is usually deployed in homes and offices.
• 802.11n: This protocol is touted as the new high-speed wireless standard. It works at both 2.4 and 5 GHz and can attain a theoretical maximum speed of 540 Mbps. It is not yet widespread, though early devices using it are already on the market.

Security measures of 802.11 allow wireless access points and wireless routers to provide authentication while logging on to the network, as well as encryption during transmission of data packets. The earliest methods of securing 802.11, called Wired Equivalent Privacy (WEP), were prone to attacks because transmissions could be intercepted and the keys used for security could be decrypted. WEP allowed relatively simple unauthorized access to wireless networks. IEEE recognized this problem and has since replaced WEP with Wi-Fi Protected Access (WPA), which is much more secure.

Universities, hospitals, airports, bookstores, coffee shops and homes commonly use 802.11 networks. The IEEE committee is constantly seeking to improve the protocol suite.