Operators are also launching voice over Wi-Fi, which provides coverage to areas not reached by cellular networks and helps consumers cut their costs by carrying the calls on their ordinary internet connection.
Popular chat apps such as WhatsApp and Messenger use VoIP for their call facilities.
According to a report by Zion Research, global demand for the VoIP services market was valued at over $83 billion in 2015 and is expected to reach over $140 billion in 2021 with a compound annual growth rate of above 9.1 percent between 2016 and 2021.
