19.4 Study on Multimedia Session Continuity uid_350051

Resources: S2

References

Document	Title/Contents
WID(s)
SP-070818	SID on Multimedia Session Continuity
Impacted Specifications
-	-
New Dedicated Specifications/Reports
TR 23.893	Feasibility Study on Multimedia Session Continuity; Stage 2

Supporting Individual Members: Orange, Telecom Italia, SK Telecom, China Mobile, Ericsson, Fujitsu Laboratories of Europe, Huawei, LG Electronics, Marvell, Motorola, NEC, Nokia, Nokia Siemens Networks, RIM, Samsung, Telcordia, Toshiba.

This study took into account ongoing activities in TISPAN and other bodies, and aligns with the following studies to result in a common framework for Service Continuity.

• System enhancements for fixed broadband access to IMS (FBI) (UID_32074)

• Voice Call Continuity between CS and IMS (incl. I-WLAN) (VCC) (UID_32091)

• Study on centralized IMS service control (FS_ICS) (UID_330012)

• 3GPP System Architecture Evolution (FS_SAE ) (UID_32085)

• Study on Mobility between 3GPP-WLAN Interworking and 3GPP Systems (FS_SM3GWLAN) (UID_350017)

• Personal Network Management (PNM) (UID_31081)

Service Continuity Stage 1 was included in TS 22.278 "Service requirements for the Evolved Packet System (EPS)".

In the context of studying the general issue of IMS sessions continuity, it was also felt necessary to investigate the following enhancements to the Rel-7 specified continuity mechanisms:

• Support of network based control of domain transfer;

• Handling of the components of a session (PS-PS session continuity), including handling of non-voice components in conjunction with PS-CS continuity;

• Support of session-level continuity between CS and non-3GPP IP accesses for MMSC.

Continuity at the IMS session layer are applicable to both EPC and non-EPC networks, and thus cannot depend solely on the existence of transport layer mobility mechanisms in the EPS.

TR 23.893 studied IMS-level MMSC including potential enhancements to IMS specifications relevant to MMSC e.g.:

• Identification of Session Continuity scenarios;

• PS-PS session continuity;

• PS-PS session continuity in conjunction with PS-CS continuity;

• Session continuity between 3GPP and non-3GPP systems (e.g. TISPAN, WiMAX);

• Network-initiated Multimedia Session Transfer;

• Mobility of media components of a session between different terminals under the control of the same user;

• Coexistence and/or potential interactions with possible underlying mobility solutions defined by 3GPP. Solutions developed within TR 23.893 should not have any impacts to underlying mobility solutions.

Consistent user experience was investigated where Services Continuity between heterogeneous access systems (e.g. different radio accesses) is needed.

Charging impacts have been studied, especially the ability to generate appropriate accounting parameters as subscribers move between various access networks.

Security in each domain is covered by existing security specifications in that specific domain; i.e. CS security aspects are covered by existing CS security specifications, IP-CAN security aspects by existing IP-CAN security specifications, non-3GPP systems security aspects by existing non-3GPP systems specifications and IMS security aspects by existing IMS security specifications. Voice Call Continuity across these domains should not compromise the security mechanisms of the individual domains.

TR 23.893 conclusions are given in clause 9 on:

• MMSC scenarios

• MMSC architecture and anchoring solution

• session transfer operator policy

• relationship between ICS and MMSC

• specification of session split/merger functionality

• T-ADS (Terminating - Access Domain Selection) and session split/merger functionality for MMSC and ICS (IMS Centralized Services)

• applicable scope of MMSC

• Single Radio MMSC

• Session Transfer Information

• UE Transfer information flows

• Keep and Release Control Mechanism in UE Transfer Mode