IEEE 802.11 is a set of protocols and standards for executing WLAN (wireless local area network) computer communication in the 5, 3.6, and 2.4 GHz frequency bands.
They're made and maintained by the IEEE 802 or the IEEE LAN/MAN Standards Committee. IEEE 802.11-2007 is the latest base version of this standard. What's more, the 802.11 family is composed of a volume of airborne modulation methods that utilize identical and basic protocol.
The most ubiquitous and widely used versions of this standard are the 802.11g and 802.11b protocols, which were improvements to the earliest standard.
Meanwhile, the first wireless networking standard is the aforementioned 802.11-1997 as well. Regardless the most widely accepted one was the 802.11b, which was then followed by 802.11g and 802.11n.
The security issues that the 802.11 family was notorious for was intentional.
Due to some export requirements of a couple of governments, the IEEE 802 had no choice but to purposefully release a security-bereft standard.
Later on, due to several legislative and governmental changes, the protocol was able to acquire improved security features in the form of 802.11i.
Meanwhile, the task of multi-streaming modulation has specifically been addressed with the launch of the 802.11n protocol.
Other 802.11 standards (from c to f, h, and j) are extensions, corrections, or service amendments to previous iterations.
Operating in the U.S. under Part 15 of the US Federal Communications Commission (FCC) Rules and Regulations, 802.11g and 802.11b both use the 2.4 GHz ISM band.
Occasional interference from Bluetooth devices, cordless telephones, and microwave ovens are unavoidable because of this government-mandated frequency band for the two standards.
This interference and vulnerability to such can be controlled by both the b and g iterations of the 802.11 family via the use of the OFDM or the orthogonal frequency-division multiplexing signaling method for the 802.11g and the DSSS or direct-sequence spread spectrum signaling method for the 802.11b.
802.11a utilizes the 5 GHz U-NII band.
In contrast to the inferior 2.4 GHz ISM frequency band wherein all the channels tend to overlap, the 5 GHz U-NII band offers over 23 non-overlapping channels at a minimum.
Improved or worsened performance with higher or lower channels may be achievable depending on the environment as well.
Another factor that can affect the effectiveness of an 802.11 standard—specifically part of the radio frequency—tend to vary between nations and regions as well.
In the United States, 802.11a and 802.11g products may be used without the need for a license, as outlined in the US FCC Rules and Regulations (Part 15).
As for the frequencies used by channels 1-6 of 802.11g and 802.11b, they fall within the amateur 2.4 GHz radio band.
The FCC Rules and Regulations (Part 97) mandates that licensed amateur radio operators may use 802.11b/g appliances; it allows for enhanced power output but discourages encryption or commercial content.
Just like with TV and radio broadcasts, the 802.11 standard divides bands into channels as well, except with the protocol, there's greater overlap and channel width allowed.