Description
A Standalone Non-Public Network (SNPN) is a complete, independent 5G system defined by 3GPP starting from Release 16. It is a non-public network (NPN) that operates using 5G New Radio (NR) and the 5G Core (5GC) network functions, but it is not reliant on a Public Land Mobile Network (PLMN) for its core network services. An SNPN is identified by a unique combination of a PLMN ID (which is specifically designated for NPN use) and a Network Identifier (NID). This SNPN Identifier (comprising PLMN ID and NID) allows UEs to discover and select the correct private network. The architecture includes all essential 5G network functions: the Next Generation Node B (gNB) for radio access, the Access and Mobility Management Function (AMF), Session Management Function (SMF), User Plane Function (UPF), Authentication Server Function (AUSF), Unified Data Management (UDM), and others, all deployed within the private domain.
How an SNPN works involves dedicated procedures for network discovery, selection, and access control. A UE configured for SNPN access scans for cells broadcasting the SNPN Identifier. Upon discovery, the UE initiates registration with the SNPN. A critical aspect of SNPN operation is authentication and credential management. SNPNs support two primary models: using credentials managed by the SNPN operator itself, or using credentials provided by a separate Credential Holder. The 5G Authentication and Key Agreement (5G-AKA) or EAP-based methods are used, often involving a private authentication server. The network can enforce strict access control, allowing only pre-authorized UEs (e.g., company devices, sensors) to connect.
The role of an SNPN is to provide a secure, isolated, and performant communication platform for vertical industries. It enables features like network slicing, ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC) tailored to the specific needs of a factory, port, hospital, or energy grid. The operator of the SNPN has full control over the network's configuration, policy, and data, ensuring that sensitive traffic remains on-premises and is not routed through public networks. This makes SNPNs a cornerstone for Industry 4.0, enabling advanced use cases like automated guided vehicles, real-time process control, and augmented reality-assisted maintenance.
Purpose & Motivation
SNPNs were created to meet the stringent requirements of industrial and enterprise digital transformation, which public networks could not fully satisfy. Public networks are designed for broad consumer coverage and general-purpose services, often lacking the guaranteed performance, ultra-low latency, data sovereignty, and deep customization needed for critical industrial operations. Previous approaches like local Wi-Fi or LTE-based private networks were either not standardized for seamless mobility and service integration (Wi-Fi) or lacked the full feature set and architectural clarity of 5G (pre-Rel-16 private LTE).
The primary problems SNPNs solve are: 1) **Isolation and Security**: Providing a physically or logically isolated network where sensitive data never leaves the premises, crucial for intellectual property protection and operational technology (OT) security. 2) **Predictable Performance**: Offering dedicated resources with guaranteed Service Level Agreements (SLAs) for latency, reliability, and bandwidth, which is essential for time-sensitive industrial automation. 3) **Operational Autonomy**: Allowing the enterprise to own and operate the network independently, without dependency on a public mobile network operator's priorities or timelines. The motivation for standardizing SNPNs in 3GPP was to create a globally harmonized, interoperable framework for private 5G, avoiding proprietary solutions and fostering a healthy ecosystem of network equipment and devices.
Classification
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (468 CRs across 4 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 16, the SNPN (Standalone Non-Public Network) function was introduced, enabling new capabilities such as support for network slicing within an SNPN, procedures for handover between an SNPN and a PLMN, and mechanisms for a UE to access PLMN services via an SNPN and vice versa. It also defined specific configuration parameters for UEs operating in SNPN access mode, including the N3IWF FQDN format, and introduced SNPN-specific attempt counters for non-3GPP access. Furthermore, the release standardized deployment scenarios and clarified handling for various abnormal cases and 5GMM cause values applicable in an SNPN.
- FQDN format of N3IWF in a standalone non-public network TS 23.501CR0841
- Configuration parameters for a UE operating in SNPN access mode TS 24.368CR0051
- Handling of non-integrity protected messages in an SNPN TS 24.501CR1453
- Serving network name in SNPN TS 24.501CR1511
- Alternative 2: Handling of a UE not allowed to access SNPN services via a PLMN by subscription with 5GMM cause value #72 TS 24.501CR2252
- N3IWF FQDN configured in a UE to support access to PLMN/SNPN services via SNPN/PLMN TS 24.502CR0079
+ 89 more changes
In Release 17, the SNPN function was enhanced to support mobility between SNPNs and between an SNPN and a PLMN, including specific impacts on AMF selection. It introduced support for using credentials owned by a separate Credentials Holder, enabling IMSI-based SUPIs and AAA servers for primary authentication. Furthermore, the release expanded service support for SNPNs, including configurations and requirements for IMS voice, emergency services, and session continuity when using an N3IWF.
- KI#3: Support for IMC for SNPN TS 23.228CR1239
- Informative guideline on supporting session/service continuity between SNPN and PLMN when using N3IWF TS 23.501CR2563
- SNPN support AAA Server for primary authentication and authorization TS 23.501CR2611
- SNPN with separate entity hosting subscription TS 23.501CR2625
- General introduction of Enhancements to Support SNPN along with credentials owned by an entity separate from the SNPN TS 23.501CR2684
- Homogeneously support SNPN connectivity for UEs with credentials owned by Credentials Holder TS 23.501CR2799
+ 166 more changes
In Release 18, the SNPN function was expanded to support new access methods, including Non-3GPP and wireline access, and to enable new use cases like network-supported off-campus wireless (NSWO) and cellular hotspots. The release also introduced specific NAI (Network Access Identifier) formats for registration via trusted access and for N5CW devices, along with new FQDN (Fully Qualified Domain Name) constructs for emergency services and N3IWF onboarding. Furthermore, it added support for the Common API Framework (CAPIF) within SNPNs and provided clarifications for network selection and access control for localized services.
- NAI format for 5G registration via trusted access using SNPN TS 23.003CR0648
- Definition of NAI format for support of NSWO using SNPN Credentials TS 23.003CR0663
- NAI format for N5CW device 5G registration via trusted access using SNPN TS 23.003CR0665
- Visited Country Emergency SNPN FQDN TS 23.003CR0671
- FQDN for SNPN N3IWF supporting Onboarding TS 23.003CR0674
- SNPN Identifier based N3IWF FQDN TS 23.003CR0687
+ 136 more changes
In Release 19, the SNPN function was enhanced with new requirements for the interconnection of SNPNs and expanded support for 5G Proximity Services (5G ProSe) within SNPNs. This included updates to numerous 5G ProSe procedures such as discovery, UE-to-network relay selection, and direct link management, as well as defining the format of the SNPN ID for these applications. Furthermore, the release introduced mechanisms for ensuring appropriate cell reselection for localized services and for an SNPN to enable secure event notification from an SNPN Credential Provider.
- Add requirements for Interconnect of SNPN in 22.261 TS 22.261CR0776
- Format of SNPN ID description for 5G ProSe applications TS 23.003CR0703
- Information for ensuring appropriate cell reselection for localized services in SNPN TS 24.501CR6486
- Update on 5G ProSe Discoverer request procedure to support 5G ProSe in SNPN TS 24.554CR0634
- Update on UE-to-network relay selection procedure to support 5G ProSe in SNPN TS 24.554CR0637
- Update on QoS handling for 5G ProSe layer-3 UE-to-network relay with N3IWF to support 5G ProSe in SNPN TS 24.554CR0639
+ 53 more changes
Explore further
Broader topics and technologies where SNPN plays a role.
Defining Specifications
3GPP specifications that define or reference SNPN, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 22.261 vk30 | 5G System Service Requirements | Rel-20 |
| TR 22.848 vj00 | Study on Interconnect of SNPN | Rel-19 |
| TS 23.003 vj50 | Numbering, addressing and identification in 3GPP | Rel-19 |
| TS 23.041 vj30 | Cell Broadcast Service and Public Warning System | Rel-19 |
| TS 23.167 vj11 | IMS Emergency Sessions | Rel-19 |
| TS 23.222 vj80 | Common API Framework for 3GPP Northbound APIs | Rel-19 |
| TS 23.228 vj50 | IMS Stage-2 Service Description | Rel-19 |
| TS 23.287 vj00 | 5G V2X Architecture Enhancements | Rel-19 |
| TS 23.289 vk10 | Mission Critical services over 5G System | Rel-20 |
| TS 23.316 vj30 | Wireline and Wireless Convergence Access Support | Rel-19 |
| TS 23.501 vk00 | 5G System Architecture Stage 2 | Rel-20 |
| TS 23.503 vk00 | 5G Policy and Charging Control Framework | Rel-20 |
| TS 23.700 vk00 | XR Services Application Enablement Layer | Rel-20 |
| TS 24.008 vj50 | 3GPP TS 24008: Core Network Protocols | Rel-19 |
| TS 24.166 vj00 | IMS Conferencing Management Object | Rel-19 |
| TS 24.167 vj00 | 3GPP IMS Management Object Specification | Rel-19 |
| TS 24.175 vj00 | Multi-Device and Multi-Identity in IMS Management Object | Rel-19 |
| TS 24.229 vj50 | IMS call control protocol based on SIP and SDP | Rel-19 |
| TS 24.275 vj00 | MO for MMTEL Basic Communication Part | Rel-19 |
| TS 24.323 vj00 | IMS Service Level Tracing Management Object | Rel-19 |
| TS 24.368 vj40 | NAS Configuration Management Object | Rel-19 |
| TS 24.391 vj00 | USSD over IMS Management Object Specification | Rel-19 |
| TS 24.417 vj00 | OIP/OIR Management Object Specification | Rel-19 |
| TS 24.424 vj00 | XCAP over Ut for Supplementary Services MO | Rel-19 |
| TS 24.501 vj50 | 5G NAS Protocols Specification | Rel-19 |
| TS 24.502 vj20 | 5G Core Access via Non-3GPP Networks; Stage 3 | Rel-19 |
| TS 24.554 vj40 | 5G Proximity Services (ProSe) Protocols | Rel-19 |
| TS 24.555 vj30 | 5G ProSe UE Policies Specification | Rel-19 |
| TS 24.558 vj50 | Edge Enabler APIs Stage 3 | Rel-19 |
| TS 24.571 vj20 | Control Plane LCS Procedures | Rel-19 |
| TS 24.578 vj00 | UE policies for A2X services in 5GS | Rel-19 |
| TS 24.587 vj30 | V2X Services Protocols for 5G System | Rel-19 |
| TS 24.588 vj00 | UE Policies for V2X Services in 5GS | Rel-19 |
| TS 28.203 vi10 | Charging management | Rel-18 |
| TS 28.557 vj00 | Management of Non-Public Networks (NPN) | Rel-19 |
| TS 28.622 vk20 | Telecommunication Management; Generic NRM Information Service | Rel-20 |
| TR 28.807 vh00 | Study on NPN Management | Rel-17 |
| TR 28.828 vi00 | Charging Aspects for Non-Public Networks | Rel-18 |
| TR 28.907 vj00 | Enhanced Management of Non-Public Networks | Rel-19 |
| TS 29.214 vj20 | Policy and Charging Control over Rx | Rel-19 |
| TS 29.222 vj40 | Common API Framework (CAPIF) for 3GPP Northbound APIs | Rel-19 |
| TS 29.244 vj40 | PFCP Specification for Control/User Plane Separation | Rel-19 |
| TS 29.502 vj50 | 5G System; Nsmf Service Based Interface; Stage 3 | Rel-19 |
| TS 29.507 vj40 | 5G Access & Mobility Policy Control Service | Rel-19 |
| TS 29.508 vj40 | 5G Session Management Event Exposure Service | Rel-19 |
| TS 29.509 vj50 | AUSF Service Based Interface Protocol | Rel-19 |
| TS 29.510 vj50 | NRF Service Based Interface Protocol | Rel-19 |
| TS 29.512 vj40 | 5G Session Management Policy Control Service | Rel-19 |
| TS 29.513 vj40 | 5G PCC Signalling Flows & QoS Mapping | Rel-19 |
| TS 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |
| TS 29.523 vj20 | 5G Policy Control Event Exposure Service | Rel-19 |
| TS 29.525 vj40 | 5G UE Policy Control Service Stage 3 | Rel-19 |
| TS 29.526 vj30 | Nnssaaf Service Based Interface Stage 3 | Rel-19 |
| TS 29.536 vj30 | NSACF Service Based Interface Protocol | Rel-19 |
| TS 29.558 vj40 | Enabling Edge Applications | Rel-19 |
| TS 29.561 vj30 | 5G Interworking with External Data Networks | Rel-19 |
| TS 31.102 vj40 | USIM Application Specification | Rel-19 |
| TS 31.111 vj30 | USIM Application Toolkit (USAT) Specification | Rel-19 |
| TS 32.255 vk10 | Telecom Management; Charging for 5G Data Connectivity | Rel-20 |
| TS 32.422 vk00 | Telecom Management: Trace Control & Configuration | Rel-20 |
| TS 33.776 vj00 | Study of ACME for 5G SBA | Rel-19 |
| TS 33.819 vg10 | 5GS Security for Vertical & LAN Services | Rel-16 |
| TS 37.320 vj00 | Minimization of Drive Tests (MDT) Overview | Rel-19 |
| TS 37.483 vj10 | E1 Application Protocol (E1AP) | Rel-19 |
| TS 38.300 vj00 | NG-RAN Overall Description | Rel-19 |
| TS 38.304 vj00 | UE RRC_IDLE and RRC_INACTIVE Procedures | Rel-19 |
| TS 38.331 vj00 | NR Radio Resource Control (RRC) Protocol Specification | Rel-19 |
| TS 38.401 vj10 | NG-RAN Architecture Specification | Rel-19 |
| TS 38.413 vj10 | NG Application Protocol (NGAP) | Rel-19 |
| TS 38.423 vj10 | Xn Application Protocol (XnAP) specification | Rel-19 |
| TS 38.463 vj00 | E1 Application Protocol (E1AP) | Rel-19 |
| TS 38.473 vj10 | 5G F1 Application Protocol (F1AP) | Rel-19 |
