If internet is already available through RJ45 in your room, then you purchased a wrong device.
Solution:
If you want to extend your existing internet connection through wireless interface, then you need to purchase an "ACCESS POINT" instead of GATEWAY.
ADSL Gateways is combination of ADSL modem and wireless gateway, where you need to connect your gateway to ADSL enabled telephone line thorugh RJ11 connector and wireless interface (sometime RJ45 interface for LAN) are avilable for client computers.
If internet is already available through RJ45 in your room, then you purchased a wrong device.
Solution:
If you want to extend your existing internet connection through wireless interface, then you need to purchase an "ACCESS POINT" instead of GATEWAY.
ADSL Gateways is combination of ADSL modem and wireless gateway, where you need to connect your gateway to ADSL enabled telephone line thorugh RJ11 connector and wireless interface (sometime RJ45 interface for LAN) are avilable for client computers.
Kind regards,