To prepare for the 3G network shutdown, your device will need to support 4G or 5G, and VoLTE (Voice over LTE/HD calling/4G voice) for uninterrupted data and voice services.

Note that some 4G devices lack VoLTE, limiting voice calls over 4G networks and are known as 4G non-VoLTE. Also, most 5G phones support 4G VoLTE, due to backward compatibility.

To determine whether your current device is 3G, 4G non-VoLTE, 4G VoLTE or 5G you can check;

1. Manufacturer information:
   • Contact your mobile device manufacturer for information about the network capabilities of your device.
2. Device specifications:
   • Search for your phone model online to find its specifications on the manufacturer's website or on trusted tech review sites.
   • Look for terms like "3G", "4G LTE", "VoLTE" or "5G" in the network specifications.
   • If you see "5G", "VoLTE" or a similar indication, your phone is likely using Voice over LTE.
3. Device settings:
   • For Android: Go to 'Settings' > 'About phone' > 'Network' or 'Status'.
   • For iOS: Go to 'Settings' > 'General' > 'About'.
4. Network indicators:
   • Check the network indicator on your phone’s status bar for icons like "3G", "4G" or "LTE".
   • If you see "5G", "VoLTE" or a similar indication, your phone is likely using Voice over LTE.
5. Test VoLTE features:
   • Make a call and see if you can use data services with 4G or 5G during the call to determine if your phone supports VoLTE.
   • If you can use 4G or 5G data while on a call, your device is likely to be using VoLTE, as non-VoLTE phones switch to 3G and cannot sustain high-speed data while on a call.

Remember, you'll need a 4G VoLTE or 5G device to continue using both voice and data once 3G network services are switched off.