Bands and Channels

802.11g's big benefit is that it operates in the same unlicensed, 2.4-GHz band in which 802.11b lives. This allows backward compatibility with existing 802.11b gear. Rather than discard old Wi-Fi equipment, you can use old equipment if you opt to move to the 802.11g standard. Unfortunately, many consumer products also use this band, and you can experience interference from a number of sources, including cordless telephones and microwave ovens.

802.11a also operates in the unlicensed 5-GHz band, which is largely uncluttered and offers many more nonoverlapping channels (assuming you use both indoor and outdoor channels) in which to operate than 802.11b and 802.11g.

Note

There is a tradeoff in range when it comes to the frequency band in which a radio broadcasts. 802.11b and 802.11g get a better range because they operate at a lower frequency than 802.11a. Lower frequencies propagate farther than higher frequencies. Longer waveforms also have an easier time penetrating obstacles, such as walls.