T-Mobile’s wireless network will be compatible with the iPhone later this year, despite the fact that the company is the only major US telecom that doesn’t sell Apple’s handset. The fourth largest wireless provider has hired Ericsson and Nokia Siemens Networks to build out a 4G LTE network valued at $4 billion.

The deal will see the two contractors install Release 10 capable hardware at all 37,000 T-Mobile cell towers which is said to increase signal quality and enhance overall performance. The move comes just a week after the company acquired the AWS spectrum licenses from AT&T as part of their breakup deal following an acquisition attempt that was ultimately shot down by regulators.

The new spectrum, combined with what T-Mobile already has, will allow the telecom to deploy LTE service in 75 percent of the top 25 markets.

In addition to the LTE rollout, T-Mobile will also see their 4G HSPA+ service expand in the 1900 MHz band in several markets this year. The company notes that early testing has shown up to a 33 percent increase in data speeds and better in-building coverage. The 1900 MHz range will also allow customers to use the iPhone on T-Mobile’s network.

The underlying question is when will T-Mobile finally ink a deal with Apple to carry the popular smartphone? A deal could already be brewing as evident by this build-out but that’s pure speculation at this point. Most suspect that Apple will release the next iPhone in Q4 like they did last year, so perhaps we will get an answer then.

The press release suggests that Release 10 hardware installation will begin in 2012 while LTE deployment won’t happen until sometime in 2013.