802.11k - set up correctly?

According to this article

https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-1/Enterprise-Mobility-8-1-Design-Guide/Enterprise_Mobility_8-1_Deployment_Guide/Chapter-11.html <-- Fig 11-9

and this

it seems all three Information Elements / Tags need to be present in the beacon frame to signify 802.11k is set up properly:

Country Element
Power Constraint Element
RM Enable Capabilities Element

I am trying to enable 802.11k by adding option ieee80211k '1' into /etc/config/wireless. With this, I check with Wireshark, and find only two of the three tags being broadcast by my routers.

The missing entry is the Power Constraint Element.

I then even tried to manipulate the /lib/netifd/hostapd.sh file to force add local_pwr_contraint=3 into hostapd.conf. It does get added and picked up by hostapd I believe (I see it in the hostapd.conf), and I was hoping this would somehow get the beacon frame to contain this "Power Constraint" tag, but nope, still nothing.

My questions are - is this Power Constraint Element even needed for 802.11k to be functional? And if yes, is there any way to make openwrt include this tag in the beacon frame?


I'm in the exact same situation as you.
I've run a tcpdump on my OpenWRT router with 802.11k enabled and a 802.11k-compatible device and I can confirm that 802.11k neighbor reports work without the Power Constraint element. The reports are correctly requested by the device and sent by the router.
From additional research it seems that the Power Constraint element was added in 802.11h, which is only relevant for 5Ghz networks. And 802.11k is indeed supposed to work on 2.4GHz networks so it makes no sense that the feature would depend on a 5GHz-exclusive feature.
Hope this helps.

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