Voice over LTE probably isn’t the coolest feature to consumers. But I assure you that being able to do this is a big deal for both the carriers and consumers. And today the President of AT&T Labs, Krish Prabhu, said that they are just about ready to release devices that will be able to do this task. at the PCIA Conference. The feature will work between two compatible devices and offer users HD quality voice transmission. The first smartphone able to make VoLTE calls should hit the carrier by the end of the year. AT&T is also currently testing their network to ensure that next year they can commit to a wider release of VoLTE-capable devices.
AT&T is not the only carrier making this move. You should also expect Verizon to release a VoLTE compatible handset this year with a wider release of the technology next year. T-Mobile offers an HD calling service but it is not over their LTE network. Sprint so far has not made any mentions of their plans.