TS 38.331 – NR Radio Resource Control (RRC)
3GPP TS 38.331 is the 3GPP Technical Specification for NR Radio Resource Control (RRC). Its official 3GPP title is “Radio Resource Control (RRC) protocol specification”. It is published in 5 releases (Rel-15 to Rel-19); the latest version is 19.4.0 in Rel-19.
Defines 5G NR RRC signaling, configurations, procedures, and ASN.1 messages between UE and NG-RAN, including mobility, measurements, sidelink, IAB, MBS, and interworking.
Releases and versions of TS 38.331
| Release | Latest version | Links |
|---|---|---|
| Rel-19 | 19.4.0 | Read · Download (3GPP) |
| Rel-18 | 18.11.0 | Read · Download (3GPP) |
| Rel-17 | 17.18.0 | Read · Download (3GPP) |
| Rel-16 | 16.22.0 | Read · Download (3GPP) |
| Rel-15 | 15.30.0 | Read · Download (3GPP) |
Scope of TS 38.331
Category: Radio Access (RRC). Technology generation: 5G. Network layer: RAN.
Who should read this specification?
- Network operators
- Device manufacturers
- Regulators and standards bodies
- Researchers and academics
Implementation notes
Complexity level: Expert. Implementation difficulty: High.
Key technologies
Excerpt from TS 38.331
1 Scope
The present document specifies the Radio Resource Control protocol for the radio interface between UE and NG-RAN.
The scope of the present document also includes:
- the radio related information transported in a transparent container between source gNB and target gNB upon inter gNB handover;
- the radio related information transported in a transparent container between a source or target gNB and another system upon inter RAT handover.
- the radio related information transported in a transparent container between a source eNB and target gNB during E-UTRA-NR Dual Connectivity.
The RRC protocol is also used to configure the radio interface between an IAB-node and its parent node [2], and the radio interface between an NCR-node and gNB [2].
Excerpt from the official 3GPP document (Rel-19). Read the full specification with interactive table of contents.
Specifications referenced by TS 38.331
- TS 36.331 E-UTRA Radio Resource Control (RRC) Protocol
- TS 33.501 5G Security Architecture
- TS 38.104 NR Base Station RF Requirements
- TS 38.213 NR Physical Layer Control Procedures
- TS 38.133 NR Radio Resource Management Requirements
- TS 38.211 NR Physical Channels and Signals
- TS 38.212 NR Multiplexing and Channel Coding
- TS 38.214 NR Physical Layer Data Channel Procedures
- TR 21.905 3GPP Terminology and Definitions
- TS 38.304 NR UE Idle and Inactive State Procedures
- TS 23.003 Numbering, Addressing and Identification
- TS 36.101 LTE UE Radio Transmission and Reception
Specifications that reference TS 38.331
- TS 23.501 5G System Architecture
- TS 23.502 5G System Procedures
- TS 33.501 5G Security Architecture
- TS 23.401 Evolved Packet System Architecture
- TS 36.331 E-UTRA Radio Resource Control (RRC) Protocol
- TS 38.300 NR and NG-RAN Overall Description
- TS 36.300 E-UTRAN Radio Interface Protocol Architecture
- TS 26.114 IMS Multimedia Telephony Client
- TS 29.571 5G Common Data Types
- TS 24.501 5GS NAS Protocol Specification
- TS 38.101 UE Radio Transmission and Reception
- TS 28.622 Generic Network Resource Information Service
Other specifications in the 38 series
- TS 38.314 NR Performance Measurements Specification
- TS 38.321 NR MAC Protocol Specification
- TS 38.322 NR Radio Link Control (RLC) Protocol Specification
- TS 38.323 PDCP Protocol Specification
- TS 38.340 Backhaul Adaptation Protocol (BAP) Specification
- TS 38.351 Sidelink Relay Adaptation Protocol (SRAP)
- TS 38.355 Sidelink Positioning Protocol (SLPP) Specification
- TS 38.391 Ambient IoT MAC Protocol
Frequently asked questions
What is 3GPP TS 38.331?
3GPP TS 38.331 is the 3GPP Technical Specification for NR Radio Resource Control (RRC). Defines 5G NR RRC signaling, configurations, procedures, and ASN.1 messages between UE and NG-RAN, including mobility, measurements, sidelink, IAB, MBS, and interworking.
Which 3GPP releases include TS 38.331?
TS 38.331 is published in 5 releases, from Rel-15 to Rel-19. The latest version on 3GPP Explorer is 19.4.0 (Rel-19).
What category does TS 38.331 belong to?
TS 38.331 belongs to the Radio Access (RRC) category of 3GPP specifications. It applies to 5G networks.
View the full specification with interactive table of contents, version history, and AI analysis.
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