Re: Extending BT HomeHub 3 wifi with Apple Airport Extreme?
I'm afraid it can't be done. You can run two separate networks with the Airport and the Homehub, but that's about it.
However, when you do run the two wireless networks separately (but WAN of the Airport plugged into a Homehub ethernet port), wireless interference is the order of the day. I found it best to stick with the one network and I chose the Airport (Timecapsule, but you catch my drift ;-).