5.2 Identities

23.4013GPPGeneral Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) accessRelease 18TS

5.2.1 EPS bearer identity

An EPS bearer identity uniquely identifies an EPS bearer for one UE accessing via E-UTRAN. The EPS Bearer Identity is allocated by the MME. When using an EPS Radio Bearer, there is a one to one mapping between EPS RB and EPS Bearer, and the mapping between EPS RB Identity and EPS Bearer Identity is made by E-UTRAN. The E-RAB ID value used at S1 and X2 interfaces to identify an E-RAB is the same as the EPS Bearer ID value used to identify the associated EPS Bearer. When using Control Plane CIoT EPS Optimisation for user data transport for the PDN connectivity service, the MME (for uplink) and UE (for downlink) uses the EPS Bearer Identity contained within the NAS PDUs to identify the associated EPS bearer.

When there is a mapping between an EPS bearer and a PDP context, the same identity value is used for the EPS bearer ID and the NSAPI/RAB ID.

In some SM signalling messages in GERAN/UTRAN, transaction identifier (TI) represents NSAPI. The TI is dynamically allocated by the UE for UE-requested PDP context activation, and by the network for network-requested PDP context activation. A corresponding allocation is also needed for EPS Bearers in order to successfully transfer Bearers to GERAN/UTRAN. The TI is deallocated when a PDP context/EPS Bearer has been deactivated. TI usage is defined in TS 23.060 [7].

5.2.2 Globally Unique Temporary UE Identity

The MME shall allocate a Globally Unique Temporary Identity (GUTI) to the UE. The GUTI is defined in TS 23.003 [9].

5.2.3 Tracking Area Identity (TAI)

This is the identity used to identify tracking areas. The Tracking Area Identity is constructed from the MCC (Mobile Country Code), MNC (Mobile Network Code) and TAC (Tracking Area Code).

A TAI should be associated with a single time zone. All TAIs served by one eNodeB shall be in the same time zone.

NOTE: Changes in the TAI of a cell can occur but are normally infrequent and linked with O+M activity.

5.2.4 eNodeB S1-AP UE Identity (eNodeB S1-AP UE ID)

This is the temporary identity used to identify a UE on the S1-MME reference point within the eNodeB. It is unique within the eNodeB.

5.2.5 MME S1-AP UE Identity (MME S1-AP UE ID)

This is the temporary identity used to identify a UE on the S1-MME reference point within the MME. It is unique within the MME.

5.2.6 Closed Subscriber Group ID

A CSG ID is a unique identifier within the scope of PLMN defined in TS 23.003 [9] which identifies a Closed Subscriber Group (CSG) in the PLMN associated with a CSG cell or group of CSG cells.

5.2.7 UE Radio Capability ID

The UE Radio Capability ID is a short pointer with format defined in TS 23.003 [9] that is used to uniquely identify a set of UE Radio Capabilities (excluding UTRAN and NB-IoT capabilities). The UE Radio Capability ID is assigned either by the serving PLMN or by the UE manufacturer, as follows:

– UE manufacturer-assigned: The UE Radio Capability ID may be assigned by the UE manufacturer in which case it includes the UE manufacturer information (i.e. a Vendor ID). In this case, the UE Radio Capability ID uniquely identifies a set of UE radio capabilities and the UE Radio Capability for Paging for this manufacturer in any PLMN.

– PLMN-assigned: If a UE manufacturer-assigned UE Radio Capability ID is not used by the UE or the serving network, or it is not recognised by the serving PLMN UCMF, the UCMF may allocate UE Radio Capability IDs for the UE corresponding to different sets of UE radio capabilities the PLMN may receive from the UE at different times. In this case, the UE Radio Capability IDs the UE receives are applicable to the serving PLMN and uniquely identify the corresponding sets of UE radio capabilities and the UE Radio Capability for Paging(s) in this PLMN. The PLMN assigned UE Radio Capability ID includes a Version ID in its format. The value of the Version ID is the one configured in the UCMF, at time the UE Radio Capability ID value is assigned. The Version ID value makes it possible to detect whether a UE Radio Capability ID is current or outdated.

NOTE: For the case the PLMN is configured to store PLMN assigned IDs in the UE manufacturer-assigned operation requested list defined in clause 5.11.3a, then the algorithm for assignment of PLMN Assigned UE Radio Capability ID shall assign different UE Radio Capability IDs for UEs with different IMEI/TAC value.

The type of UE Radio Capability ID (UE manufacturer-assigned or PLMN-assigned) is distinguished when a UE Radio Capability ID is signalled.