Hi @Decembersangel irrespective of whether you've got 4G or 5G signal, the VoLTE is a separate feature on your phone that utilises the network to make calls over your data connection. These calls function the same way as today by using up your calls allowance. Networks have stated that if your device does not support at least 4G, then you'll not be able to make calls. VoLTE brings benefits like higher quality audio, faster call connection and better coverage.
VoLTE is going to become increasingly important as the 3G switchoff happens since once that happens, there will be no 3G network for calls to fall back on, so they'll have to take place on 4G. This is why there is a recommendation to future-proof now and have a device that is VoLTE compatible for when this happens so that you don't experience any interruptions to your service.
On many devices you may not see a button or icon for those - not all networks have profiles for every manufacturer or device but a good way to indicate whether VoLTE works on your device is to simply:
Switch off Wifi
Make sure mobile data is on
Place a call
During the call check that you remain on 4G/5G
If you remain then VoLTE is working - no further action needed.
If however you end up dropping to 3G then you don't have VoLTE active. Mobile networks have contributed to the mess that is in understanding which models are supported by which network - not all phones will work everywhere! If the network you're intending to use has a list of compatible phones that is usually a good place to start in order to understand what your options are, if you want to make use of this.
In many years from now, VoNR (Voice over 5G) may become the standard that replaces this. Then we start to experience the 'real 5G', when we get to that! 😁
Hope this helps!
