Voice over long term evolution (VoLTE) is a high standard communication system.
We are using 2G/3G/4G internet.So what is basically 2G/3G/4G?. They are just internet speed. Initially we were using 2G internet.Then due to advacement in techologies we got forward to 3G and 4G.We were just focusing on internet speed because everyone uses data.For example : suppose we get 10Mb/s speed on 3G network while we get 100Mb/s speed on 4G network.
But when you are making calls through your mobile phone, we get low quality calls (2G calls) though you are using 4G. Also it take time to reach your call to whom you are calling.When you are calling to your friend your internet connection stops and after your call it takes time to get back your internet connection.
Hence requirement for better quality calls was needed and hence VoLTE came into existence.In this system voice calls are made at high quality i.e. at LTE (4G) network.When you are making calls your internet connection get disconnected but soon after the call again you are connected to internet within no time.Hence after your call, in no time you can start using your internet.Also your battery life is extended by use of VoLTE.(In ordinary calls your switch to 2G/3G while making calls and then again to 4G.This consumes more battery).It is also possible to make video calls by using VoLTE system.
As VoLTE uses 4G network for calls it may become costly depending upon which network you are using.This system can only be used on devices which support VoLTE .If a person moves out from 4G coverage, his call might be dropped
Though this is an emerging technology and soon we will get use to it..