which technology?

Hi,

I'm searching for the right solution for my problem. I have a LAN with
an Accesspoint in it for my wireless computer devices.
Next i want to install wired Devices (e.g. Xbox) that shall be
integrated into my LAN. The Problem is that i don't want to connect it
to my LAN Physically with cable.
Which technology or which device is needed? I read something about e.g.
Bridge, WDS or Repeater. So what do I need? I thought of the Airport
Express but officially it only has a "WAN" Port. Is it only WAN?
Forthermore are there cheaper or "more affordable" products?

Regards,
Jochen