A.1 Introduction

23.2793GPPCombining Circuit Switched (CS) and IP Multimedia Subsystem (IMS) servicesRelease 17Stage 2TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

This annex describes the flows and architecture for CSI originations towards IMS termination with CSI interworking.

CSI interworking is the ability to perform the interworking between e.g. a pure IMS voice/video session and a combination of a CS call and an IMS session.