As the standardization of 5G at the first stage has been successfully completed, 5G networks will be put into commercial use. In addition to the expansion of 5G network coverage and maturity of the terminal ecosystem, carriers need to consider the factors of various 5G network deployment options when deploying 5G networks.
Although data services drive 5G evolution, voice/video communication services are still important services of carriers. Like 4G networks, how to provide voice/video communication services must be first determined for 5G commercialization.
Voice over 5G (Vo5G) will be realized through extension of certain existing infrastructure, such as IP Multimedia Subsystem (IMS), and introduction of new hardware and software, such as millimeter wave based 5G radio frequency equipment, often referred to as 5G New Radio (5G NR). Vo5G will take advantage of Voice over New Radio (VoNR), ultimately replacing Voice over LTE (VoLTE) as the preeminent technology for voice communications, and causing further displacement of 3G systems.
What is Vo5G ?
3GPP has specified that 5G uses the 4G voice/video communication architecture and still provides voice/ video communication services based on
the IMS. The 4G radio access technology is LTE, and the voice/video over the LTE network is called VoLTE. The 5G radio access technology is NR, and the voice/video over the 5G network is called voice/video over NR (VoNR). VoLTE and VoNR are different access modes for IMS voice/video communication services.
In the 4G voice solution, VoLTE is the target voice/video communication solution for 4G networks. With the expansion of 4G network coverage and
maturity of the terminal ecosystem considered, global carriers have experienced the evolution from CSFB to VoLTE.
5G Voice Solution Options:
As shown in the preceding figure, in addition to VoNR, the voice/video communication solutions EPS fallback (EPS FB), RAT fallback (RAT FB), and
voice/video over eLTE (VoeLTE) (Note 1) need to be implemented by using the 5G core network (5GC).
These solutions are not defined in the 4G era.Therefore, VoNR cannot represent all 5G voice/video communication solutions. The industry needs to use Vo5G to summarize all 5G voice/video communication solutions. Vo5G should include VoNR, VoeLTE, EPS FB, and RAT FB.
Huawei recently released the Vo5G (Voice over 5G) Technical White Paper. Based on the development of Vo5G standard and the voice and video codec standard,Huawei has analysed Vo5G evolution solutions in different 5G networks and specified directions for 5G voice evolution. It also points out that deploying the IMS and accelerating the commercial use of VoLTE are the only way to move towards Vo5G.
According to the white paper, Vo5G has been standardised with the standard process of 3GPP 5G, and Vo5G must be provided based on IMS. VoLTE will become the basic voice network in the 5G era and work with Vo5G to ensure the continuity of voice services. Therefore, deploying the IMS and accelerating the commercial use of VoLTE is the only way to move towards Vo5G.
For me details you can check Mind Commerce Vo5G Market Report.
For more details : You can review Huawei white paper