Based on the recent numbers from GSMA it seems that over 50 % of the world population is now in a reach of 4G services. The number of VoLTE deployments in 2016 (May) is already close to the number of all the deployments for the year 2015.
VoLTE Deployments
But it is not just the VoLTE which is moving forward. Also the VoWifi technology is quite appealing and gaining its momentum.
VoWifi Deployments
For RCS we can still see some new deployments. However right now the RCS is a bit stagnating.
RCS Deployments
In total the number of new deployments is rising up significantly and we don’t even count in the WebRTC and M2M (Sigfox, Lora, ..) technologies.
All-IP Deployments
Sure, one thing is the number of deployments, and the other is the number of subscribers. But clearly we can see that telco engineers have a lot of work (and stress as well :-)). Also the prognosis, that with the 4th Generation all the communication will move to OTTs, were a way too optimistic/pessimistic (depends on angle). The statistics along with some more detail information can be found on GSMA pages.
GSMA Statistics
Real Time Communication 