Usage of voice over Wi-Fi or voice over LTE is expected to be five times higher in 2016 than at the start of 2015. In some ways, you might argue that represents carrier innovation. It is.

On the other hand, with the shift to Internet Protocol, packetized voice is simply a way to keep providing the legacy service in the context of the new networks.

As with so many other technology innovations, incremental revenue is not necessarily expected. The upgrade is, in many ways, a cost of doing business. Deloitte expects that 100 mobile operators worldwide will be offering at least one packet-based voice service at the end of 2016, double the amount year-on-year, and six times higher than at the beginning of 2015.

Deloitte estimates that approximately 300 million customers will be using VoWiFi or VoLTE in 2016, five times higher than at the start of 2015. In principle, VoLTE could offer higher-value services that consumers or businesses will pay more money to use. It remains to be seen whether that is a big trend, or not.