概要
- LTE網絡Initial Attach
- IMS Client 註冊
- VoLTE Call 的建立
- VoLTE Call 的釋放
- IMS Client 去註冊
VoLTE Protocol Stack
域的選擇(Domain Selection)
- UE Capability - CS voice or PS voice
- Home Operator perference - SMS over IMS or SGs
- User settings - Voice-centric or Data centric
- Visited operator preference / visited network capability