Description
The Home Policy Control Function (H-PCF) is a critical component within the 5G Core (5GC) architecture, specifically defined within the Policy Control Framework. It operates as the policy decision point for subscribers roaming outside their home network. The H-PCF resides in the Home Public Land Mobile Network (HPLMN) and interfaces with the Visited PCF (V-PCF) located in the Visited PLMN (VPLMN) via the N24 interface. Its primary role is to provide home-routed policy control, ensuring that the home operator's policies, including Quality of Service (QoS), charging rules, and access control, are enforced even when the user equipment (UE) is attached to a foreign network.
Architecturally, the H-PCF is part of the Policy Control Function (PCF), which is the unified policy framework in 5G. For roaming scenarios, the PCF is logically separated into V-PCF and H-PCF. The V-PCF interacts directly with the Session Management Function (SMF) in the visited network to enforce session-level policies. When a policy decision requires input from the home network—such as for subscriber-specific service entitlements, spending limits, or home-defined QoS profiles—the V-PCF queries the H-PCF. The H-PCF then makes the authoritative policy decision based on subscriber data from the Unified Data Repository (UDR) and potentially other home network functions.
The H-PCF works by receiving policy requests from the V-PCF over the N24 interface, which is based on HTTP/2 and uses JSON-based service-based interfaces (SBIs). These requests contain information about the UE's session, such as requested QoS, data network name (DNN), and subscription identifiers. The H-PCF evaluates this against home network policies and subscriber profiles. It then returns policy decisions, which may include authorized QoS parameters, charging methods (online/offline), and service-specific rules. The V-PCF translates these decisions into instructions for the SMF and other functions. This separation allows the visited network to handle local policy enforcement while deferring to the home network for subscriber-specific and potentially sensitive policy logic.
Key components involved with the H-PCF include the N24 interface for V-PCF communication, the Npcf interface for internal PCF service-based interactions, and integration with the UDR via the Nudr interface for accessing subscription and policy data. Its role is pivotal in maintaining service consistency, enabling advanced charging models like sponsored data, and supporting regulatory requirements for roaming. By centralizing home policy decisions, the H-PCF simplifies the visited network's policy control complexity and ensures that home operator business rules are consistently applied globally.
Purpose & Motivation
The H-PCF was introduced in 3GPP Release 15 as part of the new 5G System (5GS) architecture to address the limitations of previous policy control frameworks in roaming scenarios, particularly those from the Evolved Packet Core (EPC). In 4G EPC, roaming policy control was handled by the Home PCRF (H-PCRF) interacting with a Visited PCRF (V-PCRF) via the S9 interface. While functional, this approach had complexities in service chaining, latency due to multiple signaling hops, and limited flexibility for new 5G services like network slicing and edge computing.
The creation of the H-PCF was motivated by the need for a more agile, cloud-native, and service-based policy framework in 5G. The 5GC architecture adopted a Service-Based Architecture (SBA) with HTTP/2 and JSON, replacing the Diameter-based protocols used in EPC. The H-PCF, as part of this new framework, is designed to support dynamic policy decisions required for 5G use cases, such as network slicing, where a roaming subscriber's slice access must be authorized by the home network. It also enables more efficient home-routed traffic models and supports integration with network exposure functions for third-party services.
Furthermore, the H-PCF solves the problem of consistent policy enforcement across administrative domains. It allows home operators to retain control over subscriber experiences and charging, which is crucial for service differentiation and revenue assurance. By decoupling the policy decision point (H-PCF) from the policy enforcement point (in the visited network), it facilitates smoother inter-operator agreements and reduces the visited network's burden in managing foreign subscriber policies. This design is essential for the global scalability of 5G services and the support of complex IoT and enterprise roaming scenarios.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (231 CRs across 6 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the Home Policy Control Function (H-PCF) saw enhancements for UE policy delivery, including the ability to store UE Policy in the VPLMN and the introduction of a Reflective QoS Timer in PDU session related policy information. It also clarified and corrected procedures for initial UE policy provisioning, UE policy configuration, and policy control request triggers for updating the AM Policy Association. Furthermore, refinements were made to the enforcement of Application Detection Control and the granularity of UE policies, including UE assistance for policy evaluation.
- 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
+ 36 more changes
In Release 16, the Home Policy Control Function (H-PCF) saw enhancements including the introduction of background data transfer policy information in URSP and updates to the policy framework for Time-Sensitive Communication (TSC) and ATSSS. It also gained the capability to use a Network Identifier (NID) as an input for policy decisions and introduced new policy control request triggers for V2X communications. Furthermore, the release specified V2X policy provisioning and added serving network policy control, clarifying the applicability of UE policies across different PLMNs.
- 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 29.525CR0036
- Correction on UE Policy Association Establishment TS 29.525CR0071
+ 45 more changes
In Release 17, the H-PCF (Home Policy Control Function) saw significant enhancements, particularly in the areas of UE policy control for 5G Proximity Services (ProSe) and dynamic policy control based on network analytics. These included extending UE policy control for ProSe-based services and support for ProSe UE-to-Network relay, as well as new policy controls for data rate management per network slice with the assistance of the NWDAF. Additionally, Release 17 introduced policy control based on satellite backhaul information and enhancements for local notification and dynamic access and mobility (AM) policy changes.
- 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
+ 38 more changes
In Release 18, the H-PCF (Home Policy Control Function) saw enhancements to support new policy control capabilities including dynamic satellite backhaul, Packet Delay Variation monitoring, and L4S (Low Latency, Low Loss, Scalable throughput). It also gained functionality for Network Data Analytics Function-assisted URSPs, DN Performance Analytics in PDTQ policy, and policy updates for multi-modal services. Furthermore, the release introduced support for VPLMN-specific offloading policies, A2X policy provisioning, and policy control based on Round-Trip latency requirements.
- 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
+ 58 more changes
In Release 19, the Home Policy Control Function (H-PCF) introduced enhancements for local offloading policy to support edge computing and refined QoS notification control to include direction-specific (UL/DL) information. It also added support for spending limits in UE policy within roaming scenarios and improved policy association management based on UDM subscription data. Furthermore, the release included corrections and clarifications for energy-saving policy considerations and for the handling of UE and AM policy associations.
- 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
+ 19 more changes
In Release 20, the Home Policy Control Function (H-PCF) introduced new policy control capabilities based on abnormal user plane traffic analytics and traffic pattern analytics. It also gained functions for service adjustment based on exposure and for network energy saving, incorporating policy control for Background Data Transfer (BDT) and UE policy control. These enhancements expanded the PCF's role in managing QoS, gating, and charging decisions using new analytics inputs.
- 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 H-PCF plays a role.
Defining Specifications
3GPP specifications that define or reference H-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 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |
| TS 29.525 vj40 | 5G UE Policy Control Service Stage 3 | Rel-19 |