Final answer:
The non-overlapping channels recommended for use in a 2.4-GHz WLAN in the United States are Channels 1, 6, 11 to prevent interference and optimize network performance. (option A)
Step-by-step explanation:
When using the 2.4-GHz band for multiple access points in a WLAN located in the United States, the non-overlapping channels that should be selected are Channels 1, 6, 11. These channels are recommended because they do not overlap with each other's frequency ranges, reducing the chance of interference and improving network performance. Each of the 2.4GHz channels is 20MHz wide, but the frequency spread means that neighboring channels overlap - except for 1, 6, and 11, which are spaced sufficiently apart to avoid this issue.
Wi-Fi channels in the 2.4 GHz band have a bandwidth of 20 MHz, and their frequency ranges slightly overlap. To avoid interference, it is recommended to use non-overlapping channels. Channels 1, 6, and 11 are spaced far enough apart to minimize interference between adjacent channels.
Selecting channels like 2, 7, 12, or 3, 8, 13 may seem like they are non-overlapping, but they overlap with adjacent channels, leading to interference issues.
To optimize performance and minimize interference in a WLAN operating in the 2.4 GHz band in the United States, it is advisable to select non-overlapping channels 1, 6, and 11.