This is a followup to a previous post about sharing wireless across buildings. I have Internet access at point A. I can get a good wireless signal at point B. From point B, I can send a good wireless signal to point C. But point A and point C cannot be connected wirelessly due to obstructions. Further, points A, B, and C are in different buildings, so certainly can't be connected together with wires.
My question is: How can the guy at point C connect to the Internet through point B? It must be possible, at least from a physics perspective. All the diagrams I've seen about wireless access points has the AP attached to the first router with a cable. Seems this ought not to be necessary. Am I missing something simple?