Reports are coming in this afternoon that the Federal Communications Commission has approved AT&T’s plan to use its dormant WCS spectrum to expand its LTE network. The carrier acquired the spectrum years ago, but has been unable to use it due to concerns that it would knock out the popular Sirius satellite radio service…

The Wall Street Journal reports:

“WASHINGTON—Federal regulators signed off Wednesday on a plan that would resolve longstanding interference issues between AT&T Inc. and Sirius XM Radio Inc. and allow the wireless giant to expand its high-speed LTE network…

…This summer, the two companies jointly proposed a plan under which AT&T would use just 20 Mhz of the 30 Mhz it holds and leave the rest empty to protect Sirius’s service. AT&T could also use a different band for a fixed wireless broadband service.”

AT&T launched its LTE network late last year, and now offers the high-speed data in 77 markets. But with more than a year head start, Verizon is still the leader in US LTE deployment by a long shot, with coverage in more than 400 cities. AT&T, however, could substantially improve its footprint as a result of this new deal.

Unfortunately, this isn’t something that can happen over night. In response to the FCC’s approval announcement, the carrier said that it’s hoping to start deploying LTE over this newly-minted band by 2015. Here’s an excerpt from a blog post on the company’s website in regards to the Federal regulators’ decision:

“While we have not yet seen the final Order, we anticipate that the service rules adopted today will permit deployment of LTE technologies in the WCS band while ensuring that satellite radio services are protected from unreasonable interference.  AT&T took real risks to develop this under-utilized band and is committed to devoting the resources necessary to unlock its full potential.  We expect to commence deployment of LTE infrastructure in the band in as early as three years, allowing us to enhance our wireless broadband services.  Our customers will also win, as additional spectrum capacity becomes available to support surging mobile Internet usage.”

But it wouldn’t be surprising to see AT&T finish the rollout in less than three years. Word is, the carrier is facing a spectrum crisis, and is actively searching for new airwaves. Remember, it lost a lot of its [AWS] spectrum to T-Mobile as part of the breakup fee when the merger fell through late last year.