This is how it should work. Your wall cable should be plugged into the modem (in). Then connect your Wireless router(in) to the modem (out). If you have a desktop without wireless connection, connect the ethernet cable to the router (1,2,3,4..etc, any port will do). You will need to run the setup on your computer to configure the router. After setting up the router, your PS3 or other wireless devices should be able to find your wireless network and you can connect them without problem.