The technology is growing faster and faster nowadays, the smartphones are developing day by day with the latest processor, battery, cameras, etc. Similarly, processor making companies like Qualcomm and MediaTek creates an innovative and powerful processor every year. In the year 2017 4G VoLTE technology was very much used by smartphones manufacturers and users but there is a problem with that, you don't get the dual 4G VoLTE in both the sim cards and this lead to use only one sim active if you have both 4G sims.
MediaTek finds a solution with that and made a new processor which will allow you to use both the sim cards at 4G VoLTE technology that means you can now use 4G internet with 2nd sim also.
MediaTek's Helio P23's Cat-7 (DL) / 13 (UL) 4G LTE modem is the world's modem which will allow you to use the dual 4G VoLTE technology in your phone. This technology will help in improving the internet speed, signal strength, HD voice and video calls, etc.