Verizon and AT&T, two companies that are very much at war with each other, are joining together for the betterment of technology. The two cellular giants will work to bring HD voice calling to their networks in 2015 in the United States over existing LTE networks.
HD Voice calling will greatly improve the call quality of a phone that is capable of tapping into either service provider's LTE data network.
In addition to voice calls, the efforts of the two companies will also provide LTE support for video calling and rich messaging. Voice over LTE, or VoLTE, is only supported on a select few devices, which include Apple's iPhone 6/6+, Samsung's Galaxy S5 and LG's G2 cell phones. Outside of the 2015 expectancy, no detailed launch window was provided.
Source: Verizon Wireless