If the AVR and router are on the same circuit (breaker), a network over powerline adapter set can work, too. I tried Actiontec and that puked, but the TrendNet seems to work pretty well, although the house where I installed them is very old and I suspect the wiring is causing some issues with stability. Belkin makes them, as well as others. This way, running new cabling is unnecessary and the AVR, BD player, Smart TV can be connected to the adapter on the AV equipment end. If multiple pieces need to connect via ethernet cable, a network switch can go between the Network Over Powerline piece and everything else wired to the switch.