Airport Extreme Base Station Main and two Airport Extreme Base Station network extensions work just fine. We have an out-building that is covered in steel with no windows - wireless signal will not penetrate. Purchased TP-Link antenna and connected it to a TP-Link WR542G router inside the building. I can access the set up for the TP-Link using ethernet from my computer to the router, but I can't get it to interface wirelessly with the Airport network. Has anyone tried this? Is there another way to connect to the network from inside the building?