I have Uverse trio, (tv,phone,internet). The modem is an all in one box 3800HGV-B. It has built in wireless, and as far as I can tell, you can not set up another wireless device behind it.

U-verse is not a straight dsl router, it carrys the tv signal and the phone signal as well, there is no bridge mode, you cannot dumb modem it. The standard uverse at&t gateways are a one stop ...