What are the 2.4 GHz Wi-Fi channel characteristics, and why are only channels 1, 6, and 11 recommended for simultaneous use?

• A.The 2.4 GHz band has exactly 3 channels (numbered 1, 6, and 11); other channel numbers do not exist.
• B.Channels 1, 6, and 11 are recommended because they have higher transmit power limits than other channels.
• C.The 2.4 GHz band (2.400-2.483 GHz) has 14 channels (1-14, regional variation). Each 802.11 channel occupies 22 MHz of bandwidth. The channel spacing is 5 MHz. Channels 1, 6, and 11 are the only three channels with 25 MHz separation between center frequencies, making them non-overlapping (22 MHz channel width + 3 MHz guard band). Any other combination (e.g., channels 1, 3, 6) results in overlapping frequencies, which creates adjacent-channel interference (ACI) - more disruptive than co-channel interference because partially overlapping signals cause noise, not just medium sharing.