Fourth ranked U.S. cellular carrier T-Mobile (News - Alert) announced that it will upgrade its nationwide data network this year to allow Apple’s iPhone and certain other smartphones to connect to the network, according to the Associated Press (News - Alert) (AP). Currently, T-Mobile stands alone among the four national U.S. cellular carriers by not offering the iPhone, the AP noted.

Once T-Mobile’s wireless network has been overhauled, iPhone users from Verizon and Sprint (News - Alert) NextTel could switch to T-Mobile. AT&T subscribers’ iPhones are locked into AT&T’s network, though methods exist to “unlock” iPhones. Other smartphones with AT&T (News - Alert) service are not locked into the network, and could be switched to T-Mobile as soon as the network is changed, the AP noted.

Unlike other cell carriers, T-Mobile offers a contract-free voice and text plan, starting around $70 a month. This plan also features a 5 gigabyte data allotment. Subscribers that exceed their data limit will see data transmission rates throttled. According to the AP, a similar plan from Verizon (News - Alert), which requires a contract, is priced around $140 a month.

Currently, iPhones that migrate from AT&T to T-Mobile can access voice and slow-speed data service, but high-speed data will remain unavailable until the network is upgraded. The changes to T-Mobile’s network are part of a $4 billion upgrade that will include the deployment of more rapid 4G LTE (Long Term Evolution) data services, according to the Los Angeles Times.

“T-Mobile's looking for a future, and they clearly are going to have to invest heavily to catch up with the huge investments that have been made by AT&T and Verizon," Jack W. Plunkett, a telecom analyst and chief executive at Plunkett Research, was quoted by the Los Angeles Times. "T-Mobile is trying to modernize and become relevant again." 

According to the AP, T-Mobile’s effort to roll out LTE service next year is part of an attempt to keep competitive with other carriers, including Verizon and AT&T who currently operate LTE networks. Sprint plans to launch its own LTE service later this year. Currently, only a few cellphones have LTE compatibility, but that is expected to change as consumers embrace the higher data speeds LTE offers.