Belkin g wireless router?

I have just bought a second hand router to use with my ps3 and pc i have the pc connected with a wired connection which is fine and my ps3 is wireless but for some reason i keep getting signer out of the psn network. I didn't receive any installation manuals or cds with the router so i have asked a few questions on a ps3 forum but nobody seems to be able to help. browsing the internet is fine on the ps3 i just cannot play any games online. could any body tell me were i am going wrong.