Commissioning of the network installation

Well, whatever? The regular-priced ones can't do roaming, but if you use identical settings in the APs, you usually get fairly smooth transitions. Important to turn off auto channel and assign different channels to the APs with appropriate spacing.

Okay. That is doable (:

I talked to a friend today. He says the FritzBox should ideally be placed in the utility room, so centrally with the other network equipment.
Actually, I tend to agree with him, but how does it work with the Wi-Fi (2.4 and 5 GHz) and the DECT?

I have concerns that the signals will be absorbed by the calcium silicate walls - two walls and a wooden staircase are "in the way" for perfect reception in the living room.

So sand-lime brick is not an obstacle... reinforced concrete is... my Fritz is also in the utility room and I still have reception at the neighbor's...

Cool. Then I will try it that way for now. Telephony is also not a problem? A Siemens Gigaset xy via DECT on the FB?

What kind of Fritzbox do you have?
In my case, it is also located in the utility room and hardly reaches outside the room...

7490 - is located in the basement in a server cabinet (so it is partially shielded) and I have full reception there. However, on the ground floor, there is no sign of it anymore.