5G Voice Call Procedures
This 5G voice call procedures page groups the main procedures used in this part of the 5G signaling library so you can jump quickly into the right flow for learning, trace reading, or troubleshooting.
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What This Covers
Covers VoNR and IMS-related signaling such as registration support, session establishment, emergency handling, and fallback-related voice flows.
These procedures are useful when you want a focused view of one 5G signaling family rather than the full 5G library.
Use this category page to jump into the main voice call procedures procedures without scanning the broader 5G call flow library.
VoNR Registration and Core Voice Entry
Procedures that prepare the UE for native voice service on 5G standalone.
- VoNR Registration — IMS registration over NR
- IMS Registration Refresh / Re-registration — Maintain IMS registration continuity over time
- IMS PDU Session Establishment for Voice — Voice-specific IMS data session setup
VoNR Call Handling
End-to-end procedures for outgoing calls, incoming calls, call modification, and release.
- VoNR Mobile Originated Call — UE initiates call
- VoNR Mobile Terminated Call — UE receives call
- VoNR Call Termination — End voice session
- VoNR Call Hold / Resume — Voice session modification
Emergency and Fallback Voice Paths
Voice procedures used when emergency service or fallback continuity changes the normal VoNR path.
- VoNR Emergency Call — Emergency voice service
- EPS Fallback — 5G to LTE voice fallback
- VoLTE Fallback / Voice Continuity Comparison — Compare fallback and continuity branches for voice
- SRVCC Procedure — Single Radio Voice Call Continuity to legacy CS voice