A.7.1 Introduction

24.3373GPPIP Multimedia (IM) Core Network (CN) subsystem IP Multimedia Subsystem (IMS) inter-UE transferRelease 17Stage 3TS

This subclause shows signalling flows for adding and releasing of mediacomponent by the controller UE. Four different scenarios are considered in this subclause:

– scenario where the controller UE adds a new media component on a controllee UE. The procedures in this subclause are the same as the procedures described in subclause A.4.3 with the exception that upon the receipt of a SIP REFER request from the controller UE, the SCC AS generates a SIP re-INVITE request within the dialog to the controllee UE instead of a SIP INVITE request;

– scenario where the controller UE releases a media component from the controller UE, see subclause A.7.2.1;

– scenario where the controller UE releases a media component from the controllee UE, see subclause A.14.2.2.1; and

– scenario where the controller UE releases a media component from the controllee UE and that causes the termination of the collaborative session, see subclause A.7.2.2.2.