I flew from Texas into Lanzhou, China for a family trip yesterday. There is no mobile connectivity at all here. I used UPROAM to add over $50 into my international roaming account, but I cant call, cant text and have no data. The cell signal is strong, however. My PLUM Gator phone covers the required frequency bands. It seems that this is an issue related to mintSIM. If this issue is not fixed soon, I'll have to switch the provider in the coming year.