Matter-over-Thread pairing only close by possible

Hardware
1

Hi there,

I’m running the following Matter-over-Thread setup:

  • SLZB-06 stick connected via USB to Home Assistant (located in the basement)
  • OpenThread Border Router with its own preferred network

I’m experiencing issues when pairing devices on a different floor:

  • Pairing works reliably when the device is in the same room as the SLZB-06.
  • Pairing fails when the device is one floor above (both for mains-powered and battery devices).
  • Once paired, devices work fine and can be controlled from other floors without any issues.
  • I also tried adding a Thread repeater on the ground floor, but pairing still fails even when the device is right next to the repeater.

So effectively, I always have to bring devices close to the Border Router for pairing.

Is this expected behavior, or could there be a configuration issue preventing other Thread routers from relaying the commissioning process?

For context: I also have an Echo (4th gen) on the ground floor, but I haven’t been able to join it to the same Thread network.

Thanks!

2

Thread is not like WiFI, where devices connect to a central access point.
Thread devices are devices with weak radios, but with the ability to have packets forwarded by repeater devices, which can make the network have a far better coverage than WiFi.
Most mains powered devices can act as repeater besides their normal function, so there is no need for devices that are repeaters-only.
Often a single repeater is not enough to close a radio dead spot, so many mains powered devices will have far more functionality than with repeaters for probably around the se price.

Also remember that a rebuilt of the routing can take some time when you move a device, so give it a hour to settle in the new location to be sure it has finished its mesh joining.

3

Thanks for your feedback. After
A) waiting a few hours and
B) realizing that a mains-powered device was only detected as an end device, not as a routing end device…

repairing fixed the issue.

Pairing now also works on the other floor.