AT&T Inc. is planning to launch voice-over-LTE (VoLTE) services by the end of this year, a move that will likely make it the first of the big three U.S. operators to do so.

"We're going to be prepared to do some initial markets by the end of the year," reiterated Bill Smith, president of network operations at AT&T. (See AT&T Amplifies Its 4G Voice.)

VoLTE marks a significant break from previous 2G and 3G voice services because it converts conversations into data packets over an IP network. This will allow operators to support video calls and enhanced messaging capabilities.

AT&T, however, doesn't have blanket coverage of the U.S. with LTE yet. It has just hit 212 live markets with the new technology and expects to have covered nearly 90 percent of the country by the end of the year, but will still support 3G calls on its VoLTE handsets.

"Our solution allows you to fall back to the UMTS network" when VoLTE capabilities aren't available, Smith says.

So where might AT&T launch first with VoLTE? Smith says that's ultimately down to the marketing department, echoing the comments of Verizon Wireless's CTO last week. (See Verizon Preps Network, Waits on Marketing Nod for VoLTE and AT&T Searches for VoLTE Product 'Leader'. )

— Dan Jones, Site Editor, Light Reading Mobile