(AP) -- T-Mobile USA on Thursday said it will revamp its wireless data network this year, with the side effect of making it compatible with iPhones and some other smartphones sold by competing carriers.
T-Mobile is the smallest of the four nationwide carriers and the only one that doesn't sell the iPhone. But the reorganization of its wireless spectrum means that iPhone 4S users could migrate over from Sprint Nextel Corp. and Verizon Wireless when their contracts expire.
Owners of AT&T Inc. iPhones could move over too, if they figure out how to "unlock" their phones from AT&T's network.
AT&T does "unlock" other brands of smartphones on request, and they, too, will work on T-Mobile's revamped network.
Currently, T-Mobile undercuts the other carriers with a contract-free plan with unlimited calling and texting for $70 per month. It includes 5 gigabytes of data, after which speeds are throttled.
On a contract-based plan with Verizon, unlimited calling, texting and 5 gigabytes of data would cost $140 per month.
AT&T iPhones that are moved over to the current T-Mobile network can make phone calls and get low-speed data service, but don't get high-speed data.
The retooling of the wireless network is part of T-Mobile's plan, announced Thursday, to start "LTE" wireless data service next year. That technology provides for even higher download speeds, but relatively few phones can use it. Verizon and AT&T already have LTE networks, and Sprint is set to fire one up this year.
Another effect of the revamp is that many international visitors will be able to use their smartphones on T-Mobile's network. So far, the nationwide U.S. network that's been compatible with most phones from overseas has been AT&T's.
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