Thirded. What Tony and Tom said. To add to that, you should not need the same brand router or firmware. You can mix and match and do that just fine.

Doug: What you're referring to is a wireless repeater or wireless range extender. That would likely be the best option if he did not already have a wired network. I do this same thing in a concrete building where the primary router is on the third floor and I'm in the basement.