Technically, no US provider has "4G" which is supposedly 100mb/s..
Please note:
The ITU's definition of 4G is not just about speed. There are many other requirements, starting with an all-IP network.
100Mbps is just the ITU's suggested target mobile speed for R&D. It's not a hard requirement. Heck, 4G charts start at 10Mbps for mobile usage. Of course, just having 10Mbps does NOT equal 4G, because of all the other requirements.
In the end, though, as I've pointed out even before the ITU flip-flopped around, the public definition of "4G" will be whatever the carriers say it is. The ITU said EDGE was 3G, and every carrier ignored that silliness as well.