I use an AVM Fritz WLAN Repeater to extend the range of WLAN in my flat. The last AVM update implemented Mesh functionality to my repeater. Is there any option to use Mesh on Turris Omnia and cross-connect this to other manufacturers repeater?
Hi,
I’ve got the same setup and no, as long as there’s no real MESH standard and every company sends its own horse on the track, you can’t run all this hardware in one neat MESH WLAN. 
Suppose there is IEEE 802.11s and it is supported on the Omnia [OpenWrt Wiki] 802.11s Based Wireless Mesh Networking.
However, AVM with their proprietary software appears scarce on information of how they implemented MESH, though it appears that their MESH works only with their products.
Perhaps Wi-Fi CERTIFIED EasyMesh™ would help, if ever broadly adopted, since it aims to
remove the need to stay within a single-vendor ecosystem to provide the benefits of multiple AP (also called “mesh”) networks. Using standardized technology gives service providers and consumers more choice and flexibility.