VoLTE (Voice over LTE) is the next evolution in wireless calling. The VoLTE technology platform allows users with a compatible phone to place and receive calls over the LTE network instead of the traditional voice network. Before VoLTE, only data was transmitted over the LTE network, and voice calls were carried over the HSPA network. In May 2014, Singtel introduced the world's first commercial "full-featured" VoLTE service in Singapore. Reliance Jio announced commercial launch of 100% VoLTE service without 2G/3G based services in India on 5th Sep 2016.
Difference Between 2G, 3G, 4G, LTE and VoLTE1G, 2G, 3G and 4G are simply increasing ‘generations’ (that’s what the G stands for) of technology used in mobile devices. The first generation (1G) was analog whereas 2G began the trend for digital transmission. 3G was an evolution over 2G mostly because data bandwidth was improved and users could then enjoy faster streaming and browsing. Voice calls could’ve been potentially better too, but not like what we will now see with 4G.
The VoLTE tech provided by Jio is completely IP based, meaning even voice calls connect over data network.