3gpp tr ab cde

Shared Subscription Data Update

Summary based on the input provided by Nokia in CP-171050.

720001

Shared Subscription Data Update

eSDU

1

C4

CP-160644

CT4 have developed protocol optimizations for the Diameter based S6a/d and MAP based GR/D interfaces allowing (parts of) subscription data, which are shared by multiple UEs (e.g. MTC-UEs), to be modified by means of administrative actions without generating signalling floods on the interfaces between HSS/HLR and serving nodes (MME/SGSN/VLR).

The mechanism follows the conclusion from TR 29.813 [1] and makes use of a backward compatible extension of the reset mechanism. Instead of sending one Insert/Delete-Subscriber-Data message per UE sharing the modified data, only one extended Reset message per serving node is sent. Serving nodes supporting the mechanism will update the stored subscription data for all the sharing UEs while serving nodes not supporting the mechanism mark impacted UEs as "not confirmed", resulting in updating the data at the next radio contact.

References

[1] TR 29.813: "Study on S6a/S6d Shared Data Update".

[2] CP-160683: "CR pack on Shared Subscriber Data Update"

4. Service Domain Centralization

Summary based on the input from T-Mobile USA in SP-171020.

720022	Service Domain Centralization	SeDoC	1	S2	SP-160675
700040	Study on Service Domain Centralization	FS_SeDoC	2	S2	SP-160306
730044	Service Domain Centralization	SeDoC	2	S2	SP-160675

This work item updates 23.292 (IMS Centralized Services) to introduce optional interworking functionality that enables networks supporting both ICS and IMS to use only the IMS service domain (eliminating service logic and databases in the CS domain); the feature addresses both the service logic execution and the authentication of a network's own subscribers, and also the necessary functionality to support roaming without requiring any functional support in the other network.

In some networks, it is an overhead to maintain two separate service domains, and ensure constancy of user experience when user devices move between the domains either due to coverage, capacity, roaming, or service requirements. This work item enhances the existing ICS capabilities and introduces two new functional entities to the network that enable all the services of a subscriber to be supported by only the IMS service domain. The new functional entities that are introduced are a MSC Server enhanced for SeDoC and a ICS interworking function (ICS IWF).

The MSC Server Enhanced for SeDoC is used in place of a MSC Server (or MSC Server enhanced for ICS), and provides some of the same functions of these systems; the most notable differences are:

- Call control solely done in IMS (no CS services are supported)

- No VLR functionality (since all services are now provided by the IMS domain)

- Mapping between CS procedures and IMS procedures for

- Call control

- Supplementary services management

- Authentication and transport of encryption keys

- Emergency Services

- Support for SMS and location services typically provided by the MSC

The ICS IWF provides support for inbound and outbound roamers in networks that do not support IMS or ICS such that the other network does not need any support for IMS or ICS (including no support for SeDoC). For an outbound roamer (i.e. a SeDoC subscriber), the ICS IWF maps the procedures between the VPLMN and the HLR into IMS procedures. For an Inbound roamer, the ICS IWF maps the procedures between the HPLMN and the MSC into IMS procedures. The ICS IWF may be used independently from SeDoC to enhance ICS roaming scenarios.

The MSC Server Enhanced for SeDoC uses the IMS domain for authentication and subscription management interacting with the HSS, a new procedure is introduced to authenticate the subscriber and obtain the CS encryption keys. In the roaming case, the ICS IWF function maps the parameters between IMS authentication and MSC/HLR authentication procedures, presenting only the MSC/HLR procedure to the roaming partner network. The subscriber's service and authentication information is now only required in the HSS and any profile in the HLR is no longer used (and may be eliminated).

To support Emergency Services via the MSC Server enhanced for SeDoC, a requirement that ICS use CS capabilities for emergency calling is relaxed, allowing for IMS to provide the emergency services for the subscriber (as already defined in TS 23.167[2]); accordingly, the ICS architectures are updated to include the E-CSCF and references to the IMS procedures for emergency services support using the IMS E-CSCF are added.

References

[1] TR 23.719 – Service Domain Centralization

[2] TS 23.167 IP Multimedia Subsystem (IMS) emergency sessions

5.