VoLTE (voice over LTE) refers to the delivery of communication services – voice, video and text - over on the 4G LTE (long term evolution) network.
Video calling over LTE is referred to as ViLTE (video over LTE).
VoLTE also allows multi-media streaming and file sharing services on LTE.
As an IP-based service, VoLTE works only on IP networks.
One of the prerequisites for VoLTE is the IMS (IP multimedia subsystem) architecture within the network’s core infrastructure and the use of compatible end-user devices that are VoLTE enabled.
VoLTE services introduced by Mobile Network Operators today offer automatic switchover to circuit-switched voice when the receiving user is not VoLTE enabled. At the same time, calls from circuit-switched voice will be converted into network packets to enable these calls to be received on LTE.
The introduction of VoLTE was driven primarily by the need for an alternative to circuit-switched voice for users of LTE data. Users of LTE data had to roll back to 3G every time they needed to make a voice call or text a message. With VoLTE, users can fulfil their communication needs and access the Internet using just their 4G connection.