Content for TR 23.826 Word version: 9.0.0
6 Architecture Alternatives p. 9
6.1 VCC in the Visited Network - Alternative 1 p. 9
6.1.1 Architectural Details p. 9
6.1.1.1 General p. 9
6.1.1.2 Reference Architecture p. 10
6.1.1.3 Initial Call establishment p. 11
6.1.1.3.1 Emergency Calls established in or transferred to IMS p. 11
6.1.1.3.2 Emergency Calls established in or transferred to CS p. 12
6.1.1.4 Domain Transfers p. 14
6.1.1.5 Enhancements to Initial Call Establishment and Domain Transfers p. 14
6.1.1.5.1 General p. 14
6.1.1.5.2 Alternative message flows p. 15
6.1.1.6 Negotiation of VCC Support p. 16
6.1.2 Impact p. 17
6.1.3 Assessment p. 17
6.1.4 Procedures p. 18
6.2 VCC in the Visited Network - Alternative 2 p. 37
6.2.1 Architectural Details p. 37
6.2.2 Impact p. 39
6.2.2.1 Negotiation of VCC Support p. 39
6.2.2.2 Domain Transfer p. 40
6.2.2.3 Modified VDN and VDI p. 42
6.2.3 Assessment p. 43
6.2.4 Procedures p. 43
6.2.4.1 IMS Emergency Call Origination p. 43
6.2.4.2 CS Emergency Call Origination p. 45
6.2.4.3 Domain Transfer IMS to CS - Procedure A p. 47
6.2.4.4 Domain Transfer IMS to CS - Procedure B p. 49
6.2.4.5 Domain Transfer CS to IMS - procedure C p. 51
6.2.4.6 Domain Transfer CS to IMS - Procedure D p. 52
6.3 VCC in the Visited Network - Alternative 3 p. 54
6.4 Emergency Session Continuity in the Visited Network - Alternative 4 p. 64
7 Evaluation p. 73
8 Conclusion p. 80
8.0 General p. 80
8.1 Placement of Session Transfer Function p. 80
8.2 PS to CS Session Transfer p. 81
8.3 CS to PS Session Transfer p. 81
9 Recommendation p. 81
$ Change history p. 82
