On January 14, 2021, MCMC announced latest requirement for Voice Over LTE (VoLTE) which is an update from previous announcement of 3G Network Sunset.
The updates are as follows:
1. Scope : 4G-device that can make phone call via mobile network that supports VoLTE.
2. Previous announcement for new applications that are submitted after 6 November 2020:

3. Final update for report requirements of new applications:

4.Additional Note:
Full Approval shall be granted if applicant demonstrate compliance to VoLTE requirements through submitted test report.
Other certification requirements shall be fulfilled too in order to receive full approval. (e.g. IPV6 requirements)