QUOTE
T-Mobile USA uses a radio frequency band (1700/2100 MHz)(AWS Band) for its 3G network . The carrier states it allows faster download and upload data speeds utilizing HSPA+ technology, which allows for simultaneous voice and data. Upgrades to HSPA+ are planned for 2009 through 2010 which may boost average download speeds near 7.2Mbps to a blazing 21Mbps[citation needed]. Their HSPA+ footprint should exceed nearly 21Mbps by the end of 2010[citation needed].
http://en.wikipedia.org/wiki/T-Mobile#United_States
T-Mobile Doubles 3G Speed, AT&T Follows Suit 1/5/10
QUOTE
AT&T has no plans for HSPA+, which can hit 21mbps, but T-Mobile does. It plans to roll out HSPA+ beginning this year and offer it nationwide by mid-year. HSPA+ is currently being tested in Philadelphia.
http://www.internetnews.com/infra/article....ollows+Suit.htm