Glossary
- ACK
Abbreviation for “Acknowledgement.” ACKs are used extensively in 802.11 to provide reliable data transfers over an unreliable medium. For more details, see “Contention-Based Data Service” in Chapter 3 of 802.11 Wireless Networks: The Definitive Guide.
See Also Block ACKImplicit Feedback
- AES
Advanced Encryption Standard. A cipher selected by NIST to replace the older Data Encryption Standard (DES) in 2001 after a five-year evaluation. AES is a 128-bit block cipher which uses either 128-, 192-or 256-bit keys. It has been widely adopted by many protocols requiring the use of a block cipher, including CCMP in 802.11, though CCMP uses only 128-bit keys. AES is specified in FIPS Publication 197.
- AP
Access Point. Bridge-like device that attaches wireless 802.11 stations to a wired backbone network. For more information on the general structure of an access point, see Chapter 20 of 802.11 Wireless Networks: The Definitive Guide.
- AS
Authentication Server. The network service that validates user credentials. Usually RADIUS in 802.11 networks.
- Basic Block ACK
The original block acknowledgement specification in the 802.11e amendment allowed a receiver of a group of frames to selectively acknowledge individual 802.11 fragments. Extensions in 802.11n make the protocol more efficient for use with 802.11n networks.
See Also Compressed Block ACK
- basic service set
See BSS
- beamforming
A method of using precise phase shifts on an antenna array that focuses the resulting transmission in a particular direction. ...
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