In the United States and Canada there are 11 channels available for use in the 802.11b 2.4GHz WiFi Frequency range. This standard is defined by the IEEE.
|Channel||Lower Frequency||Center Frequency||Upper Frequency|
There are only 3 non-overlapping channels available in the 802.11b standard.These are Channels 1,6, and 11. For WiFi access points that are located near each other it is recommended that they each use one of the above non-overlapping channels to minimize the effects of interference.
This overlapping of 2.4GHz channels are better visualized from the chart below.