Originally Posted by
N1120A
That could just be a very reliable HSPA+42 network. I get 50-60 Mbps all the time on US and Canadian LTE on T-Mo.
I don't think HSPA can do 15Mbps up so it will have been LTE.
If it was an iOS device, the carrier profile controls what is shown in the status bar.
Every UK carrier has them set to display 3G for HSPA+, and 4G for LTE, unlike the US where "4G" = HSPA and LTE = actual 4G LTE.