AT&T announced Wednesday that it’s investing $14 billion into expanding its LTE network with ambitions to cover 300 million people by the end of 2014.

The company said that spectrum acquisitions and plans to implement more efficient spectrum technology on its cellular network are also part of the plan to improve its mobile Internet network.

“This is a major commitment to invest in 21st Century communications infrastructure for the United States and bring high-speed Internet connectivity,” said Randall Stephenson, AT&T’s chief executive officer in a statement. “We have the opportunity to improve AT&T’s revenue growth and cost structure for years to come, and create substantial value for shareowners.”

AT&T is also making investments on the wireline side, with plans to expand its fiber network, make speed upgrades and offer its U-verse TV, Internet and Voice over IP plans in 8.5 million additional customer locations. It is also expanding its high-speed Internet and VoIP access services, U-Verse IPDSLAM, to 24 million additional customers.

The company projected that the investments will increase earnings per share in the “mid-single-digit or better” range by the end of 2014 and that revenues and margins will grow.

In other AT&T news, the Federal Communications Commission announced Tuesday that AT&T has agreed to pay $700,000 to the U.S. Department of Treasury after mistakenly placing some unlimited data plan customers on monthly data plans. The company will also make individual refunds to those “grandfathered” customers who were allowed to keep their unlimited data plans after AT&T eliminated that option.

In a statement, AT&T spokesman Michael Balmoris said that the consent decree affects less than 0.03 percent of AT&T customers — only those who inadvertently had a monthly data plan added to their account after exchanging their phones for a new smartphone under warranty, under an insurance claim or as part of a relocation.

Balmoris added that AT&T had already identified many of those affected by the issue.

“We had already discovered and corrected the issue by Nov. 2010, and had given refunds to customers who contacted us. Based on a review of our refund process, we believe a vast majority of those customers affected by the billing error have already been made whole,” he said.

AT&T will, however, be notifying affected customers and offering them refund and plan options.