I recently upgraded my dual-boot Windows 11 / Fedora machine to a motherboard with WiFi7, and learned some things that might - or might not - be helpful to those considering a WiFi7 upgrade. I won’t take all the credit - Julien Turbide’s blog post has a very thorough discussion of what he did and discovered, and it provided me with some important a-HA! moments.
WiFi7 differs from earlier WiFi standards in a very important - and frustrating - way. A WiFi7 interface self-configures to the regulatory domain (i.e., geographic region or country) by listening for signals on all of the defined 5 GHz and 6 GHz channels and comparing this to established profiles for each country. NOTE: I will use “country” in the rest of this post instead of “regulatory domain”.
Self-configuration is done every time a WiFi7 interface is started. My computer is off more than it is on - so self-configuration is being done for every boot-up.
The process of self-configuration may take anywhere from seconds to minutes to complete. Success or failure depends upon the signals received on the defined channels in the 5 GHz and 6 GHz frequency bands. This includes WiFi access points, other possible licensed users of these bands, and any interfering noise - atmospheric, solar, or man-made - that may be present.
Self-configuration is not fool-proof. It is possible for an interface to fail to identify the region it is in, which will limit the interface to low-power transmit/receive on the 2.4 GHz band. See Julien Turbide’s blog post for both his findings, as well as an example of a script to force a WiFi7 interface to re-scan on interface start-up.
Licensed users of the 5 GHz and 6 GHz bands are defined by country. Licensed users may include military, government, spacecraft, amateur (ham), and/or commercial radio systems. For example, in the U.S., the 6 GHz band may (still) have point-to-point telecommunications systems (I know of one system in a rural area of northern California that’s probably still active). A list of potential conflicts can be found (among other places) at Wikipedia.
Unlike earlier iterations of WiFi, it is not possible to force the country by using either iw reg set or by manipulating the wireless-regdom file. With earlier versions of WiFi, it is possible to force a WiFi interface to a particular country - such as the U.S. - when a computer is located in a country - such as Greece - where some of the transmit channels will cause harmful radio interference.
With all that said…the biggest issue I encountered is that disabling Secure Boot on my machine - whether intentionally or by booting a “Live ISO” of Fedora 43 from a USB stick - disabled the WiFi7 interface on my motherboard. I am not sure if this is an intended security feature, or if this is a BIOS bug. But…after resetting the CMOS 4 times, I downgraded my machine to a WiFi6 interface.
