Samsung
Turn VoLTE Calls On or Off auf Samsung
VoLTE (Voice over LTE) sends your calls over the same LTE network your phone uses for data, instead of dropping down to a 2G or 3G voice channel. That switch is why VoLTE calls connect faster, sound clearer and typically use less battery than a traditional call setup.
The toggle sits inside your mobile network settings and is tied to your carrier profile. If a call keeps falling back to a weaker network, or connection times feel slow, checking this switch is a fast way to rule out a settings issue before blaming your carrier.
Where to find the VoLTE toggle
On Samsung phones running Android with Samsung One UI, go to Settings ➔ Connections ➔ Mobile networks ➔ Enable or disable VoLTE calls SIM 1 / 2.
On dual SIM devices, each SIM gets its own separate entry, so you can enable VoLTE for one line and leave the other on standard voice calling.
If the option is greyed out or missing entirely, your carrier profile likely does not support VoLTE on that SIM, or the feature has not been activated on your account yet. In that case, turning the toggle on or off in settings will not change anything until the carrier enables support server-side.