It wirelessly connects via the WPS Button and allows for up to 5 DECT Phones if I read it correctly.
So it connects to the router via Wi-fi. Ok
I know the instruction steps points to it using Wi-Fi, I haven't tested them yet, but the Smart Hub 2 might also support DECT Devices.
I would try it on my own AP, sadly UniFi AP doesn't support WPS, so I would have to rename the Wi-Fi SSID to match my own AP, have it connect up to the SH2, then disable the SH2 Wi-Fi and in theory it should then auto connect to my AP.
Paul