RF5G NR RNTI: Usage and Values Explained
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This document explains 5G NR RNTI (Radio Network Temporary Identifier), detailing its usage as UE identities, network identifiers, and the specific purposes they serve within the 5G NR system. RNTI is a crucial component for managing radio resources and identifying devices within the network.
- It’s similar in concept to LTE RNTI.
- Definitions are found in 3GPP TS 38.202 and 38.321 specifications.
The following tables illustrate the possible combinations of physical channels received simultaneously by a UE in the downlink.
RNTI Downlink Reception Types 5G NR
Table 1: RNTI for downlink reception types
RNTI Downlink Reception Type Combinations 5G NR
Table 2: Downlink Reception Type Combinations
Usage and Values of 5G NR RNTI
Table 3 shows RNTI values used to distinguish different types of RNTIs in 5G NR, while Table 4 outlines their usage.
RNTI Values
Table 3: RNTI Values
RNTI Usage
Table 4: RNTI Usage
5G NR UE Identifiers
Table 5 defines the various types of 5G NR UE identifiers.
- C-RNTI, CS-RNTI, INT-RNTI, P-RNTI, SI-RNTI, and SP-CSI-RNTI are used for scheduling at the cell level.
- SFI-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, and TPC-SRS-RNTI are used for power and slot format control.
- RA-RNTI and Temporary C-RNTI are used during the random access procedure.
- I-RNTI is used for NR connected to 5GC at the NG-RAN level.
| UE Identities | Description |
|---|---|
| C-RNTI | Unique UE identification used as an identifier of the RRC Connection and for scheduling |
| CS-RNTI | Unique UE identification used for Semi-Persistent Scheduling in the downlink |
| INT-RNTI | Identification of pre-emption in the downlink |
| 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 |
| 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 |
| RA-RNTI |
|
| Temporary C-RNTI |
|
| I-RNTI | It is used to identify the UE context in RRC_INACTIVE. |
Table 5: 5G NR UE Identifiers
5G NR Network Identifiers
Table 6 defines different types of 5G NR Network identifiers.
| Network Identities | Description |
|---|---|
| AMF Name | It is used to identify an AMF. |
| NCGI (NR Cell Global Identifier) | It is 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. |
| gNB ID | It is used to identify gNBs within a PLMN. The gNB ID is contained within the NCI of its cells. |
| Global gNB ID | It is 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. |
| TAI (Tracking Area identity) | It is 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. |
| S-NSSAI | It stands for Single Network Slice Selection Assistance information. It identifies a network slice. |
Table 6: 5G NR Network Identifiers
References
- 3GPP TS 38.202
- 3GPP TS 38.300
- 3GPP TS 38.321
