What is required for Wi‑Fi channels to be nonoverlapping?

For Wi-Fi channels to be nonoverlapping, they must use disjoint frequency ranges. This means that the frequency spectrum used by one channel does not overlap with the spectrum used by another channel. Overlapping channels cause co-channel interference, degrading Wi-Fi performance and reliability. For example, in the 2.4 GHz band, channels 1, 6, and 11 are commonly used because they are non-overlapping. Different security settings, unique SSIDs, or different transmission speeds do not prevent channel overlap; these are configuration options that do not affect the underlying frequency usage of the channels.