I'm curious... I know AT&T owns most of the US towers, but there are some dead spots where you just get NO SERVICE... I had a couple of questions about this. Most telecom companies have agreements to lease each others equipment so... 1) Is the IP4 w/ AT&T able to roam on T-Mobile's towers when there is low or no service?? (vice versa?) Especially in the mountains and areas of low coverage. 2) Is there anything sold that could connect via USB to extend the antenna strength of the IP4?