802.11 operates over two major spectral bands: the ISM band covering 2.4 GHz - 2.485 GHz spectrum and the 5 GHz band.

The ISM band is divided into 14 channels at different frequencies. The center frequencies are separated by 5 MHz (i.e. 2412, 2417, 2422, etc). However, the bandwidth is +/- 10 MHz. Hence, there is a significant spectral overlap on adjacent channels (i.e choosing an adjacent channel to another network is almost as bad as choosing the same channel).


Geographical location dictates which channels can be used:

  • US: Channels 1-11
  • Europe: Channels 1-13
  • Japan: Channels 1-14

Setting The Channel:

The Access Point (AP) administrator chooses a channel for a specific AP. Interference is possible. The channel selected can be the same as that chosen by a neighboring AP!

In the US, channels 1, 6, and 11 are non-overlapping (at the -3 dB points), so these are typically selected for APs.
In Europe, channels 3, 8, and 13 are typically used.

© 2024 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.