4.6 Identifiers

23.6823GPPArchitecture enhancements to facilitate communications with packet data networks and applicationsRelease 17TS

4.6.1 General

Identifiers relevant for the 3GPP network are specified in TS 23.003 [4].

4.6.2 External Identifier

A subscription used for MTC has one IMSI and may have one or several External Identifier(s) that are stored in the HSS. If there are several External Identifiers, the HSS shall store one default External Identifier and one or more additional External Identifiers.

NOTE 1: If several External Identifiers are mapped to one IMSI, some functions might not work in this release of the specification.

External Identifier shall be globally unique. It shall have the following components:

a. Domain Identifier: identifies a domain that is under the control of a Mobile Network Operator (MNO). The Domain Identifier is used to identify where services provided by the operator network can be accessed (e.g. MTC-IWF or SCEF provided services). An operator may use different domain identifiers to provide access to different services and/or MTC Service Providers.

b. Local Identifier: Identifier used to derive or obtain the IMSI. The Local Identifier shall be unique within the applicable domain. It is managed by the Mobile Network Operator.

NOTE 1: Use of External Identifiers is not restricted to MTC only.

NOTE 2: Use of IMSI outside the 3GPP operator domain is dependent on the operator policy.

4.6.3 External Group Identifier

A subscription used for MTC may be associated to one or several IMSI-Group Identifier(s) (see TS 23.003 [4]) that are stored in the HSS.

A subscription may be associated to one or several External Group Identifier(s) that are stored in the HSS. The External Group Identifier shall be formatted the same as the External Identifier that is described in clause 4.6.2. The Local Identifier is used to derive or obtain an IMSI-Group Identifier. An External Group Identifier maps to an IMSI-Group Identifier. An IMSI-Group Identifier maps to zero, one or several External Group Identifiers.

The External Group Identifier is used on the interface between the SCS/AS and the SCEF and on the interface between the SCEF and the HSS. This identifier is used in procedures such as group message delivery, communication pattern provisioning, and monitoring event configuration and deletion. When the External Group Identifier is used in the communication pattern provisioning or monitoring event configuration and deletion procedures, the HSS shall be able to resolve the External Group Identifier to an IMSI-Group Identifier and the associated External Identifier or MSISDN for each of the IMSIs in the IMSI-Group. The purpose of this association is to enable the SCEF to determine what UE Identifier to use (MSISDN or External Identifier) and derive APN from SCS/AS Identifier and the MSISDN or External Identifier to route non-IP data to the UE when non-IP data is sent to an External Group Identifier.

NOTE: Additional information can assist HSS to resolve the IMSI-Group Identifier to MSISDN or External Identifier for each of the IMSIs in the IMSI-Group, e.g. Provider Information, Service information (e.g. NIDD, MONTE). How the HSS resolves to one of the UE Identifier(s) (MSISDN or External Identifier) in a UE’s subscription is implementation specific.