So with that already up and running, decide where you’ll be placing the PS3 in relationship to the router and then buy an Ethernet cable with enough length (and a bit more for slack) to stretch between the two. Ethernet cables come in different “speeds” (10BASE-T, 100BASE-TX and 1000BASE-T ) and so must be matched to that which your network can handle (check the router’s specs), although the faster speeds are backwardly compatible with slower.
In general, Ethernet cables are moderately priced, although they tend to cost more in shorter lengths proportionally. You can get them at electronic or game stores, Radio Shack, and online. The cable has a connector on each end that looks sort of like a fat version of the one that your phone cord plugs into the wall - one end of the Ethernet cable will go into one of the router’s inputs while the other will click into the corresponding Ethernet slot on the PS3’s back (it’s best not to have the console running when you plug it in).

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