NEW ORLEANS â€"  While much of the attention on T-Mobile's planned $4 billion network upgrade has centered around its plans to launch Long Term Evolution (LTE) technology next year, there is another key component to the strategy.

The company also is looking to free up space in another part of its spectrum that should finally allow iPhone users to run on its network at full speed. The company has about a million iPhone subscribers even though devices can only run at slow 2G speeds. T-Mobile USA also does not sell the iPhone itself.

At a dinner event in New Orleans late Monday, T-Mobile chief technology officer Neville Ray said the effort to reclaim some of its 1,900-MHz spectrum should reach a critical mass in the fourth quarter of this year, allowing the company to more aggressively court AT&T subscribers who are no longer under contract.

He declined to comment on whether the company would directly target iPhone users in a big marketing push planned for later this year.

"It would make sense," Ray agreed, but added, "We're not there yet."

Read more on T-Mobile's plans for the iPhone at AllThingsDigital.