You may not have heard of voice over LTE (VoLTE) technology, but that does not mean you are not using it!
Carriers around the world are deploying this technology to get rid of GSM or CDMA-based circuit networks. The first commercial solution was presented in South Korea in August 2012 and most mobile terminals already support it.
The main idea is to use a single network (the packet network), which is now devoted to 4G data service. This network uses SIP signaling, just like the VoIP technology does to establish and manage phone calls, and voice packets are IP packets. This way, an all-IP network is created.
Voice over LTE provides high-definition voice quality thanks to the Adaptive Multirate Wide Band (AMR-WB) codec. As a result, the quality of the phone call is up to 6 times higher than that of GSM calls in circuit networks.
Also, the set-up time is up to two times quicker. Communications require less bandwidth (thanks to the greater spectral efficiency of the LTE data network) and resources used by carriers in circuit networks can be shifted to the LTE packet network. IP and Robust Header compression (RoHC) is used in voice packets, thereby reducing the overhead created by IP headers. The packet network allows for the native deployment of Rich Communication Services (RCS) like video calls, instant messaging, chats or file transfer (right from the telephony application of the terminal).
The commercial applications that already offer these services use more network resources, consume more data, and significantly reduce the battery life of cellphones (battery consumption of over 40%). Other benefits of VoLTE are those generated when using LTE technology to obtain better coverage thanks to OFDMA, as well as better operation at the cell border than with classical circuit networks.
The network is based on a reduced deployment of the IP Multimedia Subsystem (IMS) and replaces the previous development based on Voice over LTE via Generic Access Networks.
VoLTE can be incorporated using voice over WiFi, thus connecting indoor environments with bad LTE coverage. Switching from one network to the other can be easily done, without communications being cut off. Some cloud solutions can fully implement VoLTE/VoWiFi services, replicating the network infrastructure on virtual machines.
Just as with other mobile technologies, we at Teldat have carefully studied VoLTE technology from its inception and are closely following its progress, figuring out how to best implement it in our products and solutions.