What is more important when roaming on T-Mobile internationally--having a phone with more LTE Bands or more UMTS bands or it doesn't matter? T-Mobile says that their international roaming includes unlimited data capped at 128kbps for free. Although I travel the whole world, I mostly travel to Europe and want to make sure I have a phone that can make the most of the data roaming feature by having the capability to connect to as many mobile networks as possible.