You cannot just go out an purchase another modem, connect it to your cable outlet and expect it to work.
1. The modem needs to be recognized by the cable company, usually by the Mac address, and configured
2. Your cable company will probably want extra money as you now have another account on that cable spur, that's if they allow you to do it at all.
The normal way to add extra connections to your cable modem is to use a router, wireless or not, and connect all the other peripherals to the router.
You either run a cat5 Ethernet cable from the router to the Blueray player, assuming that it has an Ethernet port or you go wireless.
What is your concern with going wireless?
I want to interface my blueray player to the internet. The room where I plan to do this has a cable connection but no network connection (i have cable internet and do not want go wireless). I bought another cable modem and have connected it to the cable line but I can't get anything to communicate. What do I need to do?