LTE, or Long Term Evolution, is the fourth generation of cellular data technology. VoLTE stands for Voice over LTE. A voice call is sent as regular data over the LTE data channel rather than being sent over the cellular voice channel. Voice quality is much better due to the higher rate at which the data is transmitted and received, and if the person you are calling uses VoLTE, you can speak at the same time. Most wireless carriers treat VoLTE as regular voice service and do not count it against a data plan, though this is not always the case.