T-Mobile launched the Samsung Galaxy S III around the same time as other carriers, but due to its 4G LTE network not being deployed until this year, there was no LTE support. That’s about to change now after the Galaxy S III was spotted passing through the FCC with T-Mobile LTE support. Known as the Samsung SGH-T999L, consumers can anticipate its arrival on March 27th. The phone will also have support for HSPA+ over the 850, 1700, and 1900MHz bands, including LTE Band 17 which is utilized on AT&T smartphones. In other words, T-Mobile customers who unlock this upcoming version of the Samsung Galaxy S III, could use it on AT&T’s network.