WLAN Solution

There is a 6 stored building. In sixth floor there is a adsl modem attached with a wireless Router and with the help of this router the user using Shared Internet connection both the desktop and Laptop and they have another setup in ground floor and there is 10 userrs in diffenent rooms (Brick Wall). Presently they are using their network with ethernet LAN.There is a uplink between 6th floor and ground floor. Now they want to establish wirelessless LAN instead of wired LAN between their premises.

Please give the WLAN solution.