Not completely sure but maybe on T-mobile you can get 4G using Band 2 (1900Mhz) with this phone. https://support.t-mobile.com/docs/DOC-4988
Frequencies: Band 2 (1900 MHz), Band 4 (1700/2100 MHz), Band 12 (700 MHz)
TDD : B40; FDD : B3,B5 Dual Band: B8/B1(900/2100Mhz) GSM: B8/B3/B2(900/1800/1900Mhz) Operating Frequency