In this clause, the identities used by NR connected to 5GC are listed. For scheduling at cell level, the following identities are used:

• C-RNTI: unique UE identification used as an identifier of the RRC Connection and for scheduling;
• CG-SDT-CS-RNTI: unique UE identification used for Configured Grant-based SDT in the uplink;
• CI-RNTI: identification of cancellation in the uplink;
• CS-RNTI: unique UE identification used for Semi-Persistent Scheduling in the downlink or configured grant in the uplink;
• INT-RNTI: identification of pre-emption in the downlink;
• MCS-C-RNTI: unique UE identification used for indicating an alternative MCS table for PDSCH and PUSCH;
• P-RNTI: identification of Paging and System Information change notification in the downlink;
• SI-RNTI: identification of Broadcast and System Information in the downlink;
• SP-CSI-RNTI: unique UE identification used for semi-persistent CSI reporting on PUSCH.

For power and slot format control, the following identities are used:

• SFI-RNTI: identification of slot format;
• TPC-PUCCH-RNTI: unique UE identification to control the power of PUCCH;
• TPC-PUSCH-RNTI: unique UE identification to control the power of PUSCH;
• TPC-SRS-RNTI: unique UE identification to control the power of SRS.

During the random access procedure, the following identities are also used:

• RA-RNTI: identification of the Random Access Response in the downlink;
• MSGB-RNTI: identification of the Random Access Response for 2-step RA type in the downlink;
• Temporary C-RNTI: UE identification temporarily used for scheduling during the random access procedure;
• Random value for contention resolution: UE identification temporarily used for contention resolution purposes during the random access procedure.

For NR connected to 5GC, the following UE identity is used at NG-RAN level:

• I-RNTI: used to identify the UE context in RRC_INACTIVE.

For UE power saving purpose, the following identities are used:

• PS-RNTI: used to determine if the UE needs to monitor PDCCH on the next occurrence of the connected mode DRX on-duration.
• PEI-RNTI: used to determine if the UE needs to monitor the associated PO.

For IAB the following identity is used:

• AI-RNTI: identification of the DCI carrying availability indication for soft symbols of an IAB-DU.

For Network-Controlled Repeater the following identity is used:

• NCR-RNTI: identification of the DCI carrying side control information.

For MBS, the following identities are used:

• G-RNTI: Identifies dynamically scheduled PTM transmissions of MTCH(s);
• G-CS-RNTI: Identifies configured scheduled PTM transmissions of MTCH(s) scheduled with configured grant;
• MCCH-RNTI: Identifies transmissions of MCCH and MCCH change notification.

For sidelink, the following identities are used:

• SL-RNTI: unique UE identification used for NR sidelink communication scheduling;
• SL-CS-RNTI: unique UE identification used for configured sidelink grant for NR sidelink communication;
• SL Semi-Persistent Scheduling V-RNTI: unique UE identification used for semi-persistent scheduling for V2X sidelink communication;
• SL-PRS-RNTI: unique UE identification used for SL-PRS transmission scheduling on dedicated SL-PRS resource pool;
• SL-PRS-CS-RNTI: unique UE identification used for configured sidelink grant for SL-PRS transmission on dedicated SL-PRS resource pool.

The following identities are used in NG-RAN for identifying a specific network entity:

• AMF Name: used to identify an AMF.
• NR Cell Global Identifier (NCGI): used to identify NR cells globally. The NCGI is constructed from the PLMN identity the cell belongs to and the NR Cell Identity (NCI) of the cell. The PLMN ID included in the NCGI should be the first PLMN ID within the set of PLMN IDs associated to the NR Cell Identity in SIB1, following the order of broadcast.
• gNB Identifier (gNB ID): used to identify gNBs within a PLMN. The gNB ID is contained within the NCI of its cells.
• Global gNB ID: used to identify gNBs globally. The Global gNB ID is constructed from the PLMN identity the gNB belongs to and the gNB ID. The MCC and MNC are the same as included in the NCGI.
• Tracking Area identity (TAI): used to identify tracking areas. The TAI is constructed from the PLMN identity the tracking area belongs to and the TAC (Tracking Area Code) of the Tracking Area.
• Single Network Slice Selection Assistance information (S-NSSAI): identifies a network slice.
• Network Slice AS Group (NSAG): identifies an association to a slice or a set of slices. An NSAG is defined within a TA, used for slice-based cell reselection and/or slice-based RACH configuration. Values of NSAG IDs associated with different slice or set of slices shall be unique within a TA, also when slice-based cell reselection and slice-based RACH configuration are both supported in the TA.
• Network Identifier (NID): identifies an SNPN in combination with a PLMN ID.
• Closed Access Group Identifier: identifies a CAG within a PLMN.
• Local NG-RAN Node Identifier: used as reference to the NG-RAN node in the I-RNTI.

The core network may provide two transport layer addresses of different versions to enable that a NG-RAN node can select either IPv4 or IPv6.

The following identities are used for NR sidelink communication:

• Source Layer-2 ID: Identifies the sender of the data in NR sidelink communication. The Source Layer-2 ID is 24 bits long and is split in the MAC layer into two bit strings:
  • One bit string is the LSB part (8 bits) of Source Layer-2 ID and forwarded to physical layer of the sender. This identifies the source of the intended data in sidelink control information and is used for filtering of packets at the physical layer of the receiver;
  • Second bit string is the MSB part (16 bits) of the Source Layer-2 ID and is carried within the MAC header. This is used for filtering of packets at the MAC layer of the receiver.
• Destination Layer-2 ID: Identifies the target of the data in NR sidelink communication. For NR sidelink communication, the Destination Layer-2 ID is 24 bits long and is split in the MAC layer into two bit strings:
  • One bit string is the LSB part (16 bits) of Destination Layer-2 ID and forwarded to physical layer of the sender. This identifies the target of the intended data in sidelink control information and is used for filtering of packets at the physical layer of the receiver;
  • Second bit string is the MSB part (8 bits) of the Destination Layer-2 ID and is carried within the MAC header. This is used for filtering of packets at the MAC layer of the receiver.
• PC5 Link Identifier: Uniquely identifies the PC5 unicast link in a UE for the lifetime of the PC5 unicast link as specified in TS 23.287. The PC5 Link Identifier is used to indicate to upper layers the PC5 unicast link in which sidelink RLF was declared and corresponding PC5-RRC connection was released.

V2X sidelink communication related identities are specified in clause 8.3 of TS 36.300.