VoLTE
Voice over LTE carries calls as IP packets on the LTE bearer, so a device needs VoLTE support once older networks retire.
Definitions only — a term explained here is not a service we sell.
Voice over LTE (VoLTE) carries calls as IP packets over LTE, with the IMS core handling session control. Where 2G and 3G are retired, a device without VoLTE can use data but cannot place or receive calls.
Why the network generation matters
A 4G-only network has no circuit-switched fallback, so without VoLTE the device has no voice service and an emergency call can fail in some markets. Where 3G or 2G still runs, SRVCC can hand the call over.
The device and the operator both have to enable VoLTE. The model needs certification and the correct IMS settings, including the IMS APN, so a capable chipset is not enough. Check roaming support, then test a real call, a handover and a call while data is active. Cellular bearers compared sets voice beside the other bearers.