8 Roles for call termination for inter UE transfer

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

8.1 Introduction

This clause specifies the procedures for call termination for inter UE transfer. Procedures are specified for the SC UE and the SCC AS.

8.2 SC UE

There are no additional procedures for the SC UE over those specified in 3GPP TS 24.229 [7].

8.3 SCC AS

8.3.1 Routing incoming session requests to a controller capable UE

When the SCC AS receives an incoming initial session establishment request it checks the request against the following stored user preference criteria to see if collaborative sessions are enabled for this session:

– URI in the P-Asserted-Identity header field;

– URI in the Request-URI;

– any ICSI value in the P-Asserted-Service header field; and

– media types in the SDP offer.

If the stored user preference criteria indicates that collaborative sessions are enabled for this session then the SCC AS shall include the media feature tag g.3gpp.iut-controller along with the explicit parameter in an Accept-Contact header field in the request before forwarding.