What does "Avoid 5G DFS channel" mean in Nebula AP's radio settings?

Zyxel_Nami

The "Avoid 5G DFS channel" setting in Nebula AP's radio settings allows the AP to choose non-DFS channels to provide a stable WiFi service.

DFS, or Dynamic Frequency Selection, is a mechanism that governs the use of certain 5GHz channels to prevent interference with radar operations, such as those used by weather and military systems. These systems are protected by regulations that require wireless networks to employ DFS and Transmission Power Control (TPC) to automatically avoid frequency conflicts upon detecting radar signals. The IEEE 802.11h standard outlines the requirements for DFS implementation.

Mainly, DFS channels fall within the U-NII band, including channels 52 - 140. If your Nebula APs are operating in an area known to have RADAR devices, the "Avoid 5G DFS channel" option is highly recommended to enable.