Pretty cool app that will let you get user-provided coverage on a per-carrier basis.
Here is the web based map
http://www.rootmetrics.com/compare-carriers/Note: When looking at the map, grid hex's that don't have a color haven't been reported yet. Poor signal is red (bad) or black (worse).
You can install the app on your phone from the play market (it's available for Apple as well).
https://play.google.com/store/apps/deta ... V0cmljcyJdThe app not only lets you view coverage, but you can have it report your coverage as well.
I can't speak for other providers, but senior management at T-Mobile USA watches this stuff.
The more people who use it particularly the 'reporting' feature, the more information the providers have to improve network performance...