According to Ericsson Mobility Report 2017, VoLTE subscriptions are expected to cross 650 million in 2017.

Telecom operators including Reliance Jio and Bharti Airtel have launched VoLTE in more than 125 networks in over 60 countries across all regions.

The number of VoLTE subscriptions is projected to reach 5.5 billion by the end of 2023, accounting for more than 80 percent of the combined LTE and 5G subscriptions.
Wi-Fi calling has been implemented on over 55 networks in more than 30 countries. There are more than 1,300 VoLTE-enabled device models.

Ericsson said VoLTE technology will be the foundation for enabling voice calls over 5G access. New communication service use cases in a 5G context are being explored, such as combining them with augmented reality and virtual reality.