Multi AP, multi SSID configuration best practices

Hi there, I have been running OpenWRT for ages and the network has progressively grown with multiple VLANs and separate SSIDs per each of them (segregating home automation, guests, kids etc...).
In our new house there is the need for multiple APs, which I did install, all wired, on different channels and running the latest OpenWRT.
However, I miss a mechanism to obtain seamless roaming among them - Ubiquiti style.
Often times, devices keep the connection to the last AP they connected to, even when being in front of a much stronger one.
Any suggestion on how to improve my setup?
thanks a lot!

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Thanks for your kind reply.
How do I see whether it is working, other than relying on gut feeling...? Any logs?
thanks again!

Enable 802.11r FT function maybe a good choice.

But recently, I found a compatibily issue on 802.11r. My old Notebook with Intel WiFi Link 5300 / 5100 card, it doesn't work when the router FT enabled (notebook WiFi cannot connect to the router).

Oh that video. I watch loads of his videos. He is one BRILLIANT teacher.

Thanks. I understood better.
The remaning questions that I have are:

  1. Having multiple SSIDs on different network, shall I set a different mobility domain per SSID?
  2. I see that R1 key holder has a default value even though i set "generate PMK locally". Does it matter? If so, does it need to be different per SSID?
  3. During the fast transition, do the APs neeed to talk one another over the network? I have some VLANs on unmanaged interface, hence without an IP address...
    Thanks again!

I donot know the answer of your questions, in my small home, only one SSID, I have set the two bands of router in FT mode, the roaming works fine.

Personally, I don't recommend fast roaming (802.11r) as it may cause other issues, especially with some devices (even modern ones) that just don't play nice.

The first thing you should be doing is tuning your radios. This means ensuring that all neighboring APs are set on unique, non-overlapping channels. The power level must also be adjusted -- specificially decreased to make the overlap between any two adjacent APs as small as possible. This will ensure that the signal quality from any individual AP will drop rapidly enough as the device roams through the space to then trigger the device to specifically look to roam to a better signal strength AP. When the power levels are too high, the quality may be good enough that the client device doesn't really see the necessity to roam and thus "hangs onto" the more distant AP much longer than it should.

I think that Chris from Crosstalk Solutions does a great job explaining all this... he talks about it in the context of Unifi, but the same priniciples apply to any wifi system, provided that the tuning controls are exposed to the user (in OpenWrt, they are).

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