Until these changes are made, anyone using the iPhone on the T-Mobile network, jailbroken or unlocked, suffers on slow 2.5G EDGE.
The company has long advertised HSPA+ as fast enough to be called 4G, and intends to use 1900-megahertz spectrum for an upgraded HSPA+ network. T-Mobile plans to have several of its markets covered by upgraded HSPA+ by the end of the year.
That 1900-megahertz spectrum will also allow the carrier to support an unlocked iPhone other than in EDGE mode on its network. There is, of course, still the change it may gain access to the iPhone 5, as well.
Meanwhile, the company has also announced that it has hired Ericsson and Nokia Siemens to handle its 4G LTE build-out. In February, T-Mobile USA announced it would become the last of the Big Four wireless carriers to launch LTE, starting in 2013.
T-Mobile added that it secured the spectrum it plans to use for LTE from AT&T last week as part of the merger breakup fee, when AT&T's proposed acquisition of the nation's No. 4 wireless carrier failed. With that new spectrum and its own, T-Mobile hopes to cover 75 percent of its top 25 markets with LTE.
T-Mobile, however, has insufficient bandwidth to do a broader deployment of LTE.