T-Mobile gaining iPhone compatibility, launching 4G LTE in 2013 On Thursday, T-Mobile USA announced that its 4G LTE network will launch in 2013 and along the way the company will modify its existing 3G and 4G networks to be compatible with Apple's iPhone, no matter what carrier a consumer purchased their phone from. The moves are a part of a new road map that T-Mobile is calling its Challenger Strategy, which includes $4 billion in network upgrades as the nation's fourth-largest carrier attempts to catch up with AT&T and Verizon, which have both launched 4G LTE networks, and Sprint, which is building out its 4G LTE service to launch later this year. AT&T, Sprint and Verizon all sell Apple's iPhone and while T-Mobile doesn't, it has been vocal about wanting to carry the hugely popular device. Philipp Humm, T-Mobile USA's president and chief executive, described the company's Challenger Strategy as an effort to "relaunch the brand" of T-Mobile. As T-Mobile's network upgrades take place, the carrier's service will "be compatible with a broader range of devices, including the iPhone," Humm said on Twitter. In July, T-Mobile released an iPhone-compatible microSIM card that only worked with AT&T's version of the iPhone 4 in an effort to steal subscribers from its rival. But with its three largest competitors each selling the iPhone, T-Mobile has seen its users defect in large numbers. The network improvements will enable any U.S. iPhone owner to bring their phones over to T-Mobile and purchase calling and data service, though the carrier didn't say specify when the new compatibility would arrive. T-Mobile doesn't have a deal in place with Apple to sell the iPhone itself, and that is unlikely to change this year as the company will be spending massive amounts of money on the network upgrades. "Not carrying the iPhone led to a significant increase in contract deactivations in the fourth quarter of 2011," Humm said in a statement. In 2012 and 2013, T-Mobile USA will invest to get the business back to growth, including an incremental $1.4-billion investment in its network modernization initiative, which will total a $4-billion investment over time. T-Mobile said Thursday that it lost 706,000 U.S. subscribers as its parent company, Deutsche Telekom, reported a loss of 1.3 billion euros, or $1.73 billion, for the last three months of 2011. Last year, Deutsche Telekom agreed to sell T-Mobile USA to AT&T for $39 billion, but after U.S. regulators opposed the deal, the sale was called off and the German parent company was paid $4 billion in break-up fees and given licenses to AT&T-owned wireless spectrum -- known as AWS, or advanced wireless solutions spectrum -- in major U.S. markets, and the ability to allow its customers to roam on parts of AT&T's wireless network. T-Mobile's network is built largely on AWS spectrum, which is something Humm said the company will need more of to pull off its Challenger Strategy and 4G LTE plans. Sprint drops to loss under weight of costly iPhone T-Mobile releases Micro SIM cards for Apple iPhones T-Mobile on prices, tablets and how the iPhone 'fundamentally changed our industry'