VoNR initial procedures
Before the device can conduct VoNR calls, it must pass through a series of initial procedures. These procedures are as follows:
- Subscriber provisioning
- IMS connectivity establishment
- IMS registration
- Third-party registration
Subscriber provisioning
Several network elements must be provisioned appropriately with subscriber information for VoNR services. Some of these elements are the UDM, the Home Subscriber Server (HSS), the TAS and Service Centralization and Continuity (SCC) application servers, the Policy Control Function (PCF), and AAA servers in case of Wi-Fi calling.
The information indicating whether a subscriber is permitted access to the IMS for voice services is contained within the subscriber profile in the UDM, which acts as a central repository of subscriber information. The subscriber profile contains appropriate QoS profiles for the subscriber, and it also contains whether roaming is supported. Likewise, the UDM...
