The basic is:
Line in --> ADSL modem --> Router --> PC
or
Line in --> ADSL modem --> Router --> Access point --(wirelessly)--> PC
And you mention about Router and Cable TV??
I don't think it has anything to do with your network.
Hello, I am living in a two-floor house and I want to move my ADSL connection into wireless.
At the present I have the ADSL modem connected to a hub and the 3 PCs are connected to the hub. The PCs are on the upper floor and I am wondering whether placing the wireless router on the ground floor would be a working setup. I need the router on the ground floor in order for it to be near the TV so the cable-TV can be installed.
I am going for a 802.11g protocol router and I am asking if I would be able to have a stable-full speed internet connection.
Thanks in advance.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic