I don’t think that’s possible with the SmartThings brand Wi-Fi mesh system, is it?
That’s true of many Wi-Fi mesh systems. Both bands are given the same SSID.
Back to the original question…
It’s true that your mobile phone will probably always connect to the 5 gigahertz if it’s available. But that shouldn’t cause any problems with controlling your 2.4 MHz Once everything has been connected to the system.
Specifically in a smartthings system your mobile doesn’t Communicate directly with the hub anyway. It always goes to the smartthings cloud.
So when you have a cloud to cloud integration, your mobile can be on a completely different band, or you can be outside of the home several kilometers away, it’s all the same thing. Your mobile talks to the smartthings cloud, the smartthings cloud talks to the device cloud, the device cloud uses the Internet to talk to the device.
The only time you should run into a problem is when you are doing the initial set up for a Wi-Fi device. Many of these do require that your mobile phone running the device manufacturer’s app be on the same network as the device, and again, for many of these, it Has to be the 2.4 band.
So that’s when your mobile phone connecting automatically to your 5 GHz band can cause a problem.
Some routers will allow you to turn off the 5 GHz band temporarily, but I don’t know if the smartthings Wi-Fi mesh router does. It might not.
The Workaround Tip
The workaround is the one you already mentioned: move far enough away that your mobile phone can’t reach the 5 GHz band and it switches itself to the 2.4 band. That’s awkward, but it should work for the one time set up.
And again, once it is set up, in a smartthings environment it shouldn’t matter what band your phone is using.
A lot of people run into this when trying to set up some of the video doorbells or cameras which only work on 2.4 MHz.
Hopefully if there’s an easier way to do this with the smartthings brand Wi-Fi mesh router, someone will mention it. I’m not that familiar with that model.
We should also ask which of the two models you have. Do you have the one that uses plume for network management? Or not?