There's a few different options:
The cheapest and best is a long Ethernet cable from the router all the way to the device. These usually can be up to 100 meters. If you don't have any available ethernet ports on the router you can add a gigabit ethernet switch. I understand if a cable is hard or inconvenient to run.
Another option is a wireless gaming adapter. They basically convert from wireless to wired. Another option is a powerline adapter. These you get two transceivers one goes near your router and one goes near your device. You connect each by Ethernet. This actually then sends the network through the powerlines already in your wall.
Hope this helps.
