AI-RRM disabling 2.4 Ghz radios on multipe AP's and creating dead spots for wireless coverage

[AxL1971]

We enabled AI-RRM with Flex Radio Assignment. We have noticed on multiple AP's (CW9166I) the 2.4Ghz radio are disabled.

As an example on one of the floors in the office we have 15 access points (the office floor has a large footprint), AI RRM has decided to disable 2.4 Ghz radio on 13 access points and only enabled on 2 access points, however these access points are on opposite side of the floor thus we have dead spots across the office. The only way was to manually renable the 2.4 Ghz radio.

My understanding was AI RRM was meant to improve wireless performace, and not create a problem as we have discovered.

Anyone else noticed this issue.

Just for clarity the issue is not on the 5Ghz or 6Ghz radio only 2.4 Ghz radio

[Mloraditch]

Yes: https://community.meraki.com/t5/Wireless/AI-RRM-making-dubious-decisions/m-p/272353#M37741

I would open a support case so it gets investigated and noted/attached to/as a bug

[AxL1971]

we did open a case and came to the conclusion to just renable the 2.4 Ghz radio for the AP's that had them disabled

[RaphaelL]

Disable FRA ?

[AlexanderN]

@AxL1971 please DM the network link. This is indeed related to FRA but it's not an expected behavior. Thanks!

[cmr]

The expected behaviour in my experience is exactly half of the APs have 2.4GHz turned off, regardless of location.  Turning 13/15 off seems mad!  Hopefully @AlexanderN might find an answer.

[Ryan_Miles]

I too have seen a few locations with 15-30 APs and FRA disabling a 60-70% of the radios. It might be within spec and I've not heard any specific complaints from anyone.

@AlexanderN happy to provide dash link privately if you want to give it a look.

[AlexanderN]

Disabling 2.4GHz radios, specifically? Sure, please do.

[GIdenJoe]

Haha, well I would try to avoid running 2.4 GHz altogether but if you really need it then yes it shouldn't do that.

[AxL1971]

thankfully for corporate network only use 5 Ghz, the 2.4 Ghz is used for personal devices.

[AlexanderN]

I did not get the network link for the OP, however, after reviewing a few networks that @Ryan_Miles provided the engineering team concluded that the high impact on 2.4GHz by FRA was likely caused by APs being deployed in a compact area with strong signal coverage.

The OP also mentions floors which could contribute to the issue if the floors are thin and there is a signal leakage between floors. FRA will assume a cell size based on the neighboring AP distance, but if this AP is on the different floor this assumption will be incorrect.

All in all, we will look into improving FRA to handle this case. 

[AxL1971]

@AlexanderN I have just DM you link to network, apology for late as I missed that message 

[AlexanderN]

81% of 2.4GHz radios have been shut down by FRA. Although client SNR remains acceptable, 25% of clients are still using the 2.4GHz band. The coverage from neighboring active radios remains strong. Client RF health scores are also good. While FRA appears to be aggressive, it seems to benefit both the network and the client experience.

Currently, FRA considers client count before shutting down a radio—typically, only radios with fewer than three clients are shut down. Additionally, radios with no clients are automatically taken down during the night.

However, this approach could be improved. FRA should consider the average client count over the course of a day, rather than making decisions based solely on instantaneous or nighttime client presence. We will take action to enhance FRA accordingly.

Finally, based on the AP notes, this is a multi-floor deployment and FRA is might not be able to fully account for such scenarios. This would require further improvements. 

[AnythingHosted]

I had something very similar when I enabled AI-RRM during beta phase. Had multiple issues with things changing, causing devices (ring doorbell/camera) to go offline trying to connect to an AP much further away. 

I ended up disabling it completely.