Editing IEEE 802.11 (section)

==General description==
The 802.11 family consists of a series of [[half-duplex]] over-the-air [[modulation]] techniques that use the same basic protocol. The 802.11 protocol family employs [[carrier-sense multiple access with collision avoidance]] (CSMA/CA) whereby equipment listens to a channel for other users (including non 802.11 users) before transmitting each frame (some use the term "packet", which may be ambiguous: "frame" is more technically correct).

802.11-1997 was the first wireless networking standard in the family, but [[802.11b]] was the first widely accepted one, followed by [[802.11a]], [[802.11g]], [[802.11n]], [[802.11ac]], and [[802.11ax]]. Other standards in the family (c–f, h, j) are service amendments that are used to extend the current scope of the existing standard, which amendments may also include corrections to a previous specification.<ref name="IEEE-SA Standards Board Operations Manual">{{cite web |work=IEEE-SA Standards Board Operations Manual |publisher=IEEE-SA |title=Clause 8 - Publication |url=https://standards.ieee.org/about/policies/opman/sect8/ |access-date=2024-08-24 |url-status=live |archive-url=https://web.archive.org/web/20240531142635/https://standards.ieee.org/about/policies/opman/sect8/ |archive-date=2024-05-31 }}</ref>

802.11b and 802.11g use the 2.4-[[GHz]] [[ISM band]], operating in the United States under [[Part 15]] of the U.S. [[Federal Communications Commission]] Rules and Regulations. 802.11n can also use that 2.4-GHz band. Because of this choice of frequency band, 802.11b/g/n equipment may occasionally suffer [[Electromagnetic interference at 2.4 GHz|interference in the 2.4-GHz band]] from [[microwave oven]]s, [[cordless telephone]]s, and [[Bluetooth]] devices. 802.11b and 802.11g control their interference and susceptibility to interference by using [[direct-sequence spread spectrum]] (DSSS) and [[orthogonal frequency-division multiplexing]] (OFDM) signaling methods, respectively.

802.11a uses the [[U-NII|5&nbsp;GHz U-NII band]] which, for much of the world, offers at least 23 non-overlapping, 20-MHz-wide channels. This is an advantage over the 2.4-GHz, ISM-frequency band, which offers only three non-overlapping, 20-MHz-wide channels where other adjacent channels overlap (see: [[list of WLAN channels]]). Better or worse performance with higher or lower frequencies (channels) may be realized, depending on the environment. 802.11n and 802.11ax can use either the 2.4&nbsp;GHz or 5&nbsp;GHz band; 802.11ac uses only the 5&nbsp;GHz band.

The segment of the [[radio frequency]] spectrum used by 802.11 varies between countries. In the US, 802.11a and 802.11g devices may be operated without a license, as allowed in Part 15 of the FCC Rules and Regulations. Frequencies used by channels one through six of 802.11b and 802.11g fall within the 2.4&nbsp;GHz [[amateur radio]] band. Licensed amateur radio operators may operate 802.11b/g devices under [[Part 97]] of the FCC Rules and Regulations, allowing increased power output but not commercial content or encryption.<ref name="part97">{{cite web |title=ARRLWeb: Part 97 - Amateur Radio Service |publisher=American Radio Relay League |url=http://www.arrl.org/FandES/field/regulations/news/part97/ |access-date=2010-09-27 |url-status=live |archive-url=https://web.archive.org/web/20100309001406/http://www.arrl.org/FandES/field/regulations/news/part97/ |archive-date=2010-03-09 }}</ref>