Situation: router/modem in the basement; normal users in living; heavy users/filesharing on first floor. Could I use an Airport Express, make it pickup the signal from the router and setup a wired network between the heavy users, so that everyone still has internet connections but that the heavy users can share files between them where they are connected wired? But if you're connected to the original router you should still be able to share files with the heavy users and vice versa. Is that possible? Or should I just pull an ethernet cable from the router to the first floor. The problem is that it's difficult to get the wire over there without breaking the whole house.