Summary

In summary, we have looked at some of the key concepts and drivers behind VoNR. Circuit-switched networks are slowly being phased out and replaced with voice networks supported by IMS call control. The voice requirements for the 5G system have been defined, so the standard bodies, specifically the 3GPP, have already been looking at what the 5G system needs to support with respect to voice. There is already a great deal of interest in ultra-high-definition voice services.

We have also looked at VoNR’s high-level system architecture. It is comprised of three elements: the 5G access network, the IMS, and Policy and Charging Control (PCC). With respect to the 5G access network, we have looked at some key elements such as the gNB, UPF, AMF, SMF, and UDM. Regarding IMS, we have seen there are elements such as CSCFs, HSS, SCC, and TAS.

We have also analyzed VoNR’s initial procedures. Before making and receiving calls, the VoNR subscribers must conduct these initial...