Description
The Group ID for Network Selection (GIN) is a network identifier defined in 5G system specifications starting from 3GPP Release 17. It is structurally part of the Public Land Mobile Network (PLMN) ID or used in conjunction with it. A PLMN ID is typically composed of a Mobile Country Code (MCC) and a Mobile Network Code (MNC). The GIN provides an additional level of grouping, allowing multiple distinct PLMNs (each with their own MNC) to be logically associated under a single group identifier. This group could represent a consortium of operators, a corporate network spanning multiple countries, or a service provider with agreements with several access networks. The GIN is signaled in system information blocks (SIBs) over the radio interface and is used by the User Equipment (UE) during the cell selection and reselection procedures.
Architecturally, the GIN is broadcast by the Radio Access Network (RAN) in SIB1 and other relevant system information, as specified in TS 38.331 (Radio Resource Control protocol). The NG-RAN node (gNB) is configured with this parameter by the Operation and Maintenance (OAM) system or the Core Network. When a UE is searching for a suitable cell, it reads the PLMN ID and, if present, the GIN from the broadcast channels. The UE's policy, which may be pre-configured in the Universal Subscriber Identity Module (USIM) or provided by the network via ANDSP (Access Network Discovery and Selection Policy), can instruct it to prioritize cells broadcasting a specific GIN. For example, a UE belonging to a global enterprise may be configured to select any network broadcasting the enterprise's GIN, regardless of the specific MNC, ensuring connectivity on preferred partner networks while roaming.
How it works involves both the network and the UE. The network operator configures the gNBs belonging to a consortium to broadcast the agreed-upon GIN value. The UE, during its initial PLMN selection or higher-priority search, evaluates not just the PLMN ID but also the GIN. If the UE's policy contains a GIN entry with higher priority than the registered PLMN's HPLMN (Home PLMN) or other PLMNs, it may attempt to camp on a cell broadcasting that GIN. This mechanism is detailed in TS 23.501 (System Architecture) and TS 38.304 (User Equipment procedures in idle and inactive modes). The GIN thus adds a new dimension to network selection, moving beyond a strict one-to-one PLMN identity to a more flexible group-based model. This is particularly powerful for non-public networks (NPNs) and seamless roaming agreements, where service continuity and policy-driven access are paramount.
Purpose & Motivation
GIN was created to address the limitations of traditional PLMN-based network selection in increasingly complex 5G deployment scenarios. Prior to GIN, a UE selected a network based solely on its PLMN ID (MCC+MNC). This was insufficient for modern use cases like: 1) A global enterprise that has service agreements with multiple local operators in different countries – without GIN, each operator would be a separate PLMN, requiring complex policy lists in the UE. 2) Roaming consortia where members want to offer a unified "network brand" to users. 3) Network slicing scenarios where a slice provider might be a different entity than the infrastructure PLMN owner. The GIN provides a logical grouping mechanism to solve these problems.
Historically, network selection was driven by the Home PLMN and a list of Equivalent Home PLMNs (EHPLMN). This was a rigid, flat list. The introduction of GIN in Rel-17, part of the broader enhancements for 5G system efficiency and support for non-public networks, allows for a hierarchical or tag-based selection policy. It enables more dynamic and user-centric network attachment. For operators, it simplifies the management of roaming agreements and allows for new business models where service provision can be decoupled from a specific MNC. The motivation was to enhance mobility, especially for vertical and enterprise users, by providing a standardized way to identify a "group of networks" that should be treated with a common policy, thereby improving the user experience during automatic network selection.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (300 CRs across 6 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the Group ID for Network Selection (GIN) was newly introduced as an identifier to be used during SNPN selection. Its purpose is to enhance the likelihood of a UE selecting a preferred SNPN that supports either a Default Credentials Server or a Credentials Holder. This provides a mechanism for more efficient network discovery and selection based on group-specific credential management capabilities.
- Selection of NAS procedures for E-UTRA connected to both EPC and 5GC TS 23.501CR0147
- Clarification on PCF selection TS 23.501CR0015
- Adding the new clause about SMSF selection TS 23.501CR0016
- Corrections to UPF selection and resolution of related Editor's Note TS 23.501CR0044
- Slice selection cleanup TS 23.501CR0047
- Corrections to Combined N3IWF/ePDG Selection TS 23.501CR0057
+ 35 more changes
In Release 16, the Group ID for Network Selection (GIN) was introduced as a new identifier specifically for SNPN (Standalone Non-Public Network) selection. Its primary purpose is to increase the likelihood of a UE selecting a preferred SNPN that supports either a Default Credentials Server (DCS) or a Credentials Holder (CH). This enhancement provides a more targeted network selection mechanism for devices operating in SNPN environments.
- CIoT Introduction of CN Selection and Steering TS 23.501CR0896
- ATSSS-SMF and UPF selection TS 23.501CR0761
- Trusted non-3GPP Access Network Selection TS 23.501CR0783
- eSBA communication schemas related to general discovery and selection TS 23.501CR0799
- eSBA communication schemas related to UDM and UDR discovery and selection TS 23.501CR0800
- Use of analytics for SMF selection TS 23.501CR0940
+ 94 more changes
In Release 17, the Group ID for Network Selection (GIN) was introduced as a new identifier specifically for SNPN selection. Its purpose is to enhance the likelihood of selecting a preferred SNPN that supports either a Default Credentials Server (DCS) or a Credentials Holder (CH). This function is detailed for UEs with SNPN credentials from a CH using an AAA Server.
- NWDAF discovery and selection TS 23.501CR2575
- NWDAF discovery and selection based on provided ML models TS 23.501CR2585
- UP path selection enhancement based on analytics info provided by NWDAF TS 23.501CR2586
- NWDAF discovery and selection for model sharing TS 23.501CR2614
- KI #1-1, I-SMF selection TS 23.501CR2634
- Adding some parameters for local NEF selection TS 23.501CR2656
+ 52 more changes
In Release 18, the Group ID for Network Selection (GIN) function was enhanced to support the selection of Standalone Non-Public Networks (SNPNs) that provide a specific authentication service. Specifically, the GIN identifier is now used during SNPN selection to increase the likelihood of selecting a preferred SNPN that supports a Default Credentials Server (DCS) or a Credentials Holder (CH). This provides a more targeted network discovery mechanism for devices with specific group authentication requirements.
- N3IWF selection enhancement for support of S-NSSAI needed by UE TS 23.501CR3707
- Discovery and Selection of the NWDAF Supporting Federated Learning in 5GC TS 23.501CR3772
- KI#4 23.501 AF traffic influence for common EAS, DNAI selection TS 23.501CR3788
- Common EAS/DNAI selection by AF TS 23.501CR3789
- Assistance to Member Selection Functionality for Application Operation TS 23.501CR3910
- Service area provisioning and LADN aspects for enhanced group management TS 23.501CR3914
+ 64 more changes
In Release 19, the Group ID for Network Selection (GIN) function was enhanced to improve the selection of a Standalone Non-Public Network (SNPN) that supports a Default Credentials Server or a Credentials Holder. This enhancement specifically aids UEs with SNPN credentials from a Credentials Holder using an AAA Server during the SNPN selection process. The update provides a more targeted mechanism to increase the likelihood of connecting to a preferred SNPN that can authenticate the UE based on its group credentials.
- RVAS with target NF selection enhancement. TS 23.501CR5364
- NF discovery and selection by target PLMN TS 23.501CR5399
- Support of UPF selection according to the conclusion in FS_UPEAS_Ph2 TS 23.501CR5441
- Exposure enhancements for static UE IP address assignment and 5G VN group's User Plane Security Policy TS 23.501CR5492
- I-SMF selection/insertion based on local offloading allowed indication TS 23.501CR5604
- Support of L-PSA UPF Selection Considering N6 Delay TS 23.501CR5437
+ 24 more changes
In Release 20, the Group ID for Network Selection (GIN) was introduced as a new identifier specifically for SNPN selection. Its purpose is to increase the likelihood of a UE selecting a preferred SNPN that supports either a Default Credentials Server (DCS) or a Credentials Holder (CH). This enhancement provides a more targeted network selection mechanism for devices relying on group-based credentials.
- SMF and PCF Selection for UIA_ARC TS 23.501CR6504
Explore further
Broader topics and technologies where GIN plays a role.
Defining Specifications
3GPP specifications that define or reference GIN, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.501 vk00 | 5G System Architecture Stage 2 | Rel-20 |
| 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 |