Only certain slices of it. The article you linked to mentions the frequencies in the US that must use DFS. This table in the article _it_ links to goes into muc

Only certain slices of it. The article you linked to mentions the frequencies in the US that must use DFS. This table in the article _it_ links to goes into much more detail. <https://en.wikipedia.org/wiki/List_of_WLAN_channels#4.9%E2%80%935.0_GHz_(802.11j)_WLAN https://en.wikipedia.org/wiki/List_of_WLAN_channels#4.9%E2%8...> Look for the cells that contain "DFS" to see on which channels APs are required to channel hop if they believe they have heard radar. In my personal experience, channel hopping works fine.