Description
The Visited Policy Control Function (V-PCF) is a fundamental component of the 5G Core (5GC) network architecture, specifically designed for handling policy control in roaming scenarios. When a User Equipment (UE) attaches to a 5G network outside its home operator's coverage (the Visited PLMN), the V-PCF in that visited network becomes responsible for policy decisions related to that roaming session. It is part of the visited network's Control Plane Function (CPF) set. The V-PCF interfaces with several key network functions. Crucially, it communicates with the Home PCF (H-PCF) in the subscriber's home network via the N24 reference point, a service-based interface. Through this interface, the V-PCF can retrieve subscriber-specific policy information, such as allowed network slice selections, subscribed QoS profiles, and spending limits. The V-PCF also interfaces with other visited network functions like the Access and Mobility Management Function (V-AMF) via the N15 interface for access and mobility-related policies, and with the Session Management Function (V-SMF) via the N7 interface for session management policies (PCC rules). The V-PCF acts as a policy decision point (PDP), translating the high-level service requirements from the H-PCF and network triggers into concrete policy rules. These rules govern aspects such as which network slice instance the UE can access, the QoS parameters for its Protocol Data Unit (PDU) sessions, and policies related to charging and traffic steering. The V-PCF then pushes these decisions to the relevant enforcement functions (like the V-SMF) within the visited network. This architecture ensures that the home operator's policy framework is consistently applied even when the subscriber's traffic is routed through a foreign network's user plane functions.
Purpose & Motivation
The V-PCF was introduced with the 5G System (5GS) in 3GPP Release 15 to provide a modern, service-based, and flexible policy control framework for roaming, superseding the earlier PCRF-based architecture used in 4G. The 5G system introduced new complexities like network slicing, diverse service requirements (eMBB, URLLC, mMTC), and a service-based architecture (SBA). A simple extension of the legacy V-PCRF concept was insufficient. The V-PCF was designed to be the central policy arbiter in the visited network, capable of handling policy decisions for these new 5G paradigms. It solves the problem of applying granular, slice-aware, and service-specific policies from the home network within the infrastructure of a different operator. By having a dedicated policy function in the visited domain that communicates seamlessly with the home domain, it enables advanced roaming features like seamless access to specific network slices, consistent application of QoS policies for mission-critical services, and support for edge computing scenarios in visited locations. It provides the necessary control plane separation and flexibility required for 5G's diverse use cases while maintaining operator autonomy and commercial agreements between home and visited networks.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (268 CRs across 6 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the V-PCF (Visited Policy Control Function) was newly introduced to enable the provisioning of VPLMN-specific UE policy information, including URSP rules, during roaming. This allows for local traffic routing within the visited network, as a V-PCF can provide a local DNN to the AMF. Additionally, the release clarified procedures for UE policy delivery and storage in the VPLMN, ensuring proper policy control in roaming scenarios.
- Updates of QoS Notification Control description and data model TS 29.514CR0028
- Correction on Notification control for GBR QoS flow TS 23.503CR0004
- Addition of Reflective QoS Timer in PDU session related policy information TS 23.503CR0005
- UE policies granularity and UE assistance for policy evaluation TS 23.503CR0011
- Update of UDR policy related subscription TS 23.503CR0021
- Corrections to description of session management related policy enforcement TS 23.503CR0025
+ 47 more changes
In Release 16, enhancements for the V-PCF included the introduction of a new UE Policy Control Request Trigger specifically for V2X communications and the ability for the V-PCF to provide a local DNN to the AMF, enabling VPLMN-specific URSP rules to route traffic locally. Furthermore, the release expanded policy control by specifying V2X policy provisioning and adding Network Identifier (NID) as an input for policy decisions. These updates provided the visited network with greater control over policy enforcement for specialized services like V2X and wireline access.
- Access and mobility related policy information for 5G-RG TS 23.503CR0236
- Update to Policy Framework for TSC TS 23.503CR0310
- Introduction of background data transfer policy information in URSP TS 24.526CR0043
- Specifying and adding reference for V2X Policy TS 24.526CR0052
- Adding NID as input for policy decisions TS 29.507CR0061
- Serving PLMN UE AMBR control TS 29.507CR0062
+ 55 more changes
In Release 17, the V-PCF (Visited Policy Control Function) gained new capabilities for dynamic access and mobility (AM) policy control and enhanced UE policy provisioning. Specifically, it can now provide a VPLMN-specific URSP rule to a roaming UE, enabling local traffic routing when the V-PCF supplies a local DNN to the AMF during SMF selection. Furthermore, enhancements were made for policy control based on network slice data rates and for supporting ProSe (Proximity Services) UE policies.
- BSF enhancement on PCF Discovery for dynamic AM policy TS 23.503CR0506
- Access and mobility policy control functionality to enable dynamic change of AM Policies TS 23.503CR0520
- Policy control based on satellite backhaul information TS 23.503CR0539
- ProSe Policy TS 23.503CR0533
- Policy control of data rate per network slice TS 23.503CR0552
- Policy control enhancement for local notification TS 23.503CR0587
+ 44 more changes
In Release 18, enhancements for the V-PCF included the introduction of VPLMN-specific offloading policy for HR-SBO and the ability for a V-PCF to provide a local DNN to the AMF, enabling a VPLMN-specific URSP rule to route traffic locally. Furthermore, policy control was extended to support new scenarios such as dynamic satellite backhaul and L4S, while also introducing support for Packet Delay Variation monitoring and reporting.
- NWDAF- assisted URSPs introduced in policy decision TS 23.503CR0769
- Policy control for dynamic satellite backhaul TS 23.503CR0788
- DN Performance Analytics usage in PDTQ policy TS 23.503CR0799
- Policy update to support policy control enhancements for multi-modal services TS 23.503CR0835
- Updates on PDU session related policy information TS 23.503CR0871
- VPLMN Specific Offloading Policy for HR-SBO TS 23.503CR0925
+ 64 more changes
In Release 19, key enhancements for the V-PCF included the introduction of a VPLMN-specific URSP rule to route traffic based on a local DNN provided by the V-PCF, and new support for spending limits for UE Policy with CHF information in roaming scenarios. These changes refined the control of UE and AM Policy Associations and improved policy handling for local offloading and edge computing.
- Minimize number of UE and AM Policy Associations TS 23.503CR1288
- Local Offloading Policy to support Local Handling of Edge Computing TS 23.503CR1348
- KI#1 Clarification on Local Offloading Policy TS 23.503CR1401
- PCF use of QoS and policy assistance information analytic TS 23.503CR1303
- PDU Set support in QoS Notification Control and Alternative QoS TS 23.503CR1441
- 23.503 Support of uplink rate control for QoS flows at RAN TS 23.503CR1531
+ 23 more changes
In Release 20, the V-PCF's capabilities were expanded to include policy control based on new abnormal user plane traffic analytics and traffic pattern analytics. Furthermore, enhancements were introduced for service adjustment based on exposure and for UE policy control supporting network energy saving, including the addition of BDT and PDTQ. These updates provided the visited network's policy function with more dynamic, analytics-driven control mechanisms for QoS and service management.
- Policy control based on abnormal user plane traffic analytics and traffic pattern analytics TS 23.503CR1599
- Service Adjustment based on Exposure - Policy TS 23.503CR1600
- Adding BDT, PDTQ and UE policy control for network energy saving TS 23.503CR1612
- Policy control based on new Abnormal User Plane Traffic Analytics TS 23.503CR1613
- Correction on QoS and policy assistance analytics TS 23.503CR1627
Explore further
Broader topics and technologies where V-PCF plays a role.
Defining Specifications
3GPP specifications that define or reference V-PCF, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.503 vk00 | 5G Policy and Charging Control Framework | Rel-20 |
| TS 24.502 vj20 | 5G Core Access via Non-3GPP Networks; Stage 3 | Rel-19 |
| TS 24.526 vj30 | UE Policies for 5GS; Stage 3 | Rel-19 |
| TS 29.507 vj40 | 5G Access & Mobility Policy Control Service | Rel-19 |
| TS 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |
| TS 29.525 vj40 | 5G UE Policy Control Service Stage 3 | Rel-19 |