The iPhone 5 GSM model A1428 supports UMTS/HSPA+/DC-HSDPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz); LTE (Bands 4 and 17) according to Apple's spec sheet. LTE Band 4 is 1700/2100, which is T-Mobile's AWS band for HSPA+. Would it be possible for the phone to use this band for HSPA+ if LTE is not available? If not, could it possibly be enabled through jailbreaking? I have T-Mobile and I'm not switching carriers anytime soon. I know that T-Mobile is refarming their spectrum to use 1900 for HSPA+, but that will take a while. So, would the iPhone 5 (model A1428) work on T-Mobile's 4G (HSPA+)? I'd try it, but I really don't want to spend $650 to be a guinea pig.