|Please do not use CAP LETTERS. It is considered shouting.|
You said, "UVERSE MODEM SYSTEM". I am betting this new Modem is an all-in-one Modem, Router, Switch and WAP. If this is the case and you still want to use your old router, you will need to call their tech support and see if you can configure their device into bridge mode.
The other option is to for go your router and connect all of your devices into their system.