TS 24.501 – 5GS NAS Protocol Specification
3GPP TS 24.501 is the 3GPP Technical Specification for 5GS NAS Protocol Specification. Its official 3GPP title is “Non-Access-Stratum (NAS) protocol for 5G System (5GS)”. It is published in 6 releases (Rel-15 to Rel-20); the latest version is 20.1.0 in Rel-20.
Defines 5G NAS mobility and session management procedures, security, registration, network slicing, interworking, and IoT support.
Releases and versions of TS 24.501
| Release | Latest version | Links |
|---|---|---|
| Rel-20 | 20.1.0 | Read · Download (3GPP) |
| Rel-19 | 19.8.0 | Read · Download (3GPP) |
| Rel-18 | 18.14.0 | Read · Download (3GPP) |
| Rel-17 | 17.18.1 | Read · Download (3GPP) |
| Rel-16 | 16.15.0 | Read · Download (3GPP) |
| Rel-15 | 15.7.0 | Read · Download (3GPP) |
Scope of TS 24.501
Category: Core Network (NAS). Technology generation: 5G. Network layer: CoreNetwork.
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 24.501
1 Scope
The present document specifies the non-access stratum (NAS) procedures in the 5G system (5GS) used by the protocols for:
- mobility management between the user equipment (UE) and the access and mobility management function (AMF) for both 3GPP access and non-3GPP access; and
- session management between the user equipment (UE) and the session management function (SMF) for both 3GPP access and non-3GPP access.
The 5GS mobility management (5GMM) protocol defined in the present document provides procedures for the control of mobility when the user equipment (UE) is using the NG radio access network (NG-RAN), non-3GPP access network, or both. The 5GMM protocol also provides control of security for the NAS protocols.
The 5GS session management (5GSM) protocol defined in the present document provides procedures for the handling of 5GS PDU sessions. Together with the bearer control provided by the access stratum, this protocol is used for the control of user-plane resources.
For both NAS protocols the present document specifies procedures for the support of inter-system mobility between the NG-RAN and the evolved universal terrestrial radio access (E-UTRAN), between the NG-RAN and the non-3GPP access network connected to the EPC, and between the non-3GPP access network connected to the 5G core network (5GCN) and the E-UTRAN.
For both NAS protocols the present document specifies procedures for the support of mobility between the NG-RAN and the non-3GPP access network connected to the 5GCN.
In addition, the present document specifies the procedures in the 5GS for UE policy delivery service between the UE and the policy control function (PCF) for both 3GPP access and non-3GPP access.
The present document is applicable to the UE, the access and mobility management function (AMF), the session management function (SMF), and the PCF in the 5GS.
The clauses in the present document are common for both 3GPP access and non-3GPP access unless it is explicitly stated that they apply to 3GPP access only or non-3GPP access only.
Excerpt from the official 3GPP document (Rel-19). Read the full specification with interactive table of contents.
Specifications referenced by TS 24.501
- TS 23.503 5G Policy and Charging Control Framework
- TS 24.007 Layer 3 Architecture for GSM/UMTS/EPS/5GS
- TS 24.008 NAS Call, Mobility and Session Procedures
- TS 24.011 Short Message Service (SMS) Support Procedures
- TS 24.229 IMS SIP/SDP Call Control Protocol
- TS 24.301 EPS NAS Mobility and Session Management
- TS 24.302 Access to EPC via non-3GPP networks; Stage 3
- TS 24.368 NAS Configuration Management Object
- TS 24.502 Non-3GPP Access Network Discovery and Selection
- TS 24.526 5GS UE Policies
- TR 21.905 3GPP Terminology and Definitions
- TS 24.623 XCAP Protocol for Supplementary Services
Specifications that reference TS 24.501
- TS 23.501 5G System Architecture
- TS 23.502 5G System Procedures
- TS 33.501 5G Security Architecture
- TS 24.008 NAS Call, Mobility and Session Procedures
- TS 24.229 IMS SIP/SDP Call Control Protocol
- 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 38.331 NR Radio Resource Control (RRC)
- TS 29.571 5G Common Data Types
- TS 23.503 5G Policy and Charging Control Framework
- TS 24.301 EPS NAS Mobility and Session Management
Other specifications in the 24 series
- TS 24.482 MCS Identity Management & Authentication
- TS 24.483 Mission Critical Services Management Objects
- TS 24.484 Mission Critical Services Configuration Management
- TS 24.486 V2X Application Enabler (VAE) Protocol Spec
- TS 24.502 Non-3GPP Access Network Discovery and Selection
- TS 24.503 TISPAN Endorsement of SIP/SDP Call Control
- TS 24.504 Communication Diversion (CDIV) Protocol Specification
- TS 24.505 Protocol Description of the Conference Service
Frequently asked questions
What is 3GPP TS 24.501?
3GPP TS 24.501 is the 3GPP Technical Specification for 5GS NAS Protocol Specification. Defines 5G NAS mobility and session management procedures, security, registration, network slicing, interworking, and IoT support.
Which 3GPP releases include TS 24.501?
TS 24.501 is published in 6 releases, from Rel-15 to Rel-20. The latest version on 3GPP Explorer is 20.1.0 (Rel-20).
What category does TS 24.501 belong to?
TS 24.501 belongs to the Core Network (NAS) category of 3GPP specifications. It applies to 5G networks.
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