It is best to switch off the WLAN in the normal router and connect one of the Deco's as a master to the router via a network cable. The easiest way to configure the Deco's is via mobile. When they are placed, check the transmission rates with the tool and, if necessary, move the devices slightly and test them again. This can increase reception and data rates considerably, especially if you want to distribute them over several floors. I bought a set of 3 and only need 2 devices due to the optimisation and have one as a reserve, so to speak, in case something happens.

These devices connect via WLAN. The master device is connected to the router, then the extensions must be paired with the master.