From Devialet Tech Support: How Phantom, Dialog & Wifi Router communicate

[GarthP]

Until recently I didn't know about the in built PLC and when the wireless wasn't reliable I opted to use TP-Link PLN devices, plugged into the same sockets as the Phantoms had been. Works brilliantly.

I have other issues (see blow up thread) which some are suggesting is down to plugging into the passthrough power sockets on the PLNs but I feel dubious about that.