In most countries all routers have the same maximum power so you see little variation on distance and wall penetration. You may encounter folk that think one router rules them all but unless you go rogue and get some illegal high power router that you can't buy at a store, the answer is this is not how this is solved.
I use powerline networking if walls stand in the way.
Currently I have a Linksys router that supports the 802.11g protocol but the range is not sufficent. The computer that is the most distance one sometimes can't even connect to the network. Problem is that the access point is located in a small office that needs to cover the computers in the main house.
I know I have to buy a 802.11n router since what I've been able to find out has better range that the g protocol, but I don't know how this works through walls?
The range between access point -> edge computer is about 65 feet.
Is the Apple Airplus Express/Extreme good?