Earlier this year in an announcements T-Mobile says they are going to improved voice calling with the arrival of its iPhone 5 later this month. And expecting to be the only wireless carrier in the US which delivers nation-wide HD Voice. Now it seems AT&T also on their way to support this technology. The company has released an official statement to confirm that HD Voice for their users. While they are expecting a 2013 release begins to route voice calling over its LTE network.