What is H-PCRF (Home policy and charging rules function)

H-PCRF (Home Policy and Charging Rules Function) Explained Technically

In the context of mobile network architectures, particularly those employing Packet Switched Streaming Service (PSS) or Next Generation Packet Core (NG-Core), H-PCRF (Home Policy and Charging Rules Function) plays a crucial role in policy control and charging for roaming subscribers.

Here's a breakdown of its functionality:

Purpose:

• Acts as the policy and charging enforcement entity for a Mobile Network Operator's (MNO's) home network.
• Defines and enforces policies related to service delivery, Quality of Service (QoS), and charging for roaming subscribers visiting other networks (Visited PLMNs - Public Land Mobile Networks).
• Communicates with the PCRF (Policy and Charging Rules Function) of the Visited PLMN to ensure consistent policy enforcement and seamless service experience for roaming subscribers.

Relationship with PCRF:

• Each PLMN has its own PCRF responsible for policy control and charging within its network.
• The H-PCRF in the home network acts as the authoritative source for policies and charging rules applicable to its subscribers when they roam.
• The H-PCRF communicates with the Visited PLMN's PCRF using Diameter protocol to exchange policy and charging information for roaming subscribers.

Functionality of H-PCRF:

• Policy Enforcement: The H-PCRF defines and enforces policies for roaming subscribers based on their subscriptions, network conditions, and MNO agreements with the Visited PLMN. These policies could include:
  • Service limitations (e.g., data usage caps, allowed applications)
  • QoS parameters (e.g., priority levels, bandwidth allocation)
  • Charging rules (e.g., flat rates, per-usage charges)
• Charging Information: The H-PCRF provides the Visited PLMN's PCRF with charging information specific to the roaming subscriber. This information is used for accurate billing by the home network.
• Real-time Control: The H-PCRF can dynamically update policies and charging rules for roaming subscribers based on real-time network conditions or user behavior.

Benefits of H-PCRF:

• Consistent Policy Enforcement: Ensures that roaming subscribers experience service delivery and charging according to their home network policies.
• Efficient Charging: Enables accurate billing for roaming services by providing the Visited PLMN with relevant charging information.
• Improved User Experience: Contributes to a seamless roaming experience by ensuring consistent service rules and avoiding unexpected charges.

Technical Considerations:

• The specific functionalities of H-PCRF depend on the chosen 3GPP standard for packet core networks (e.g., 3GPP TS 23.214).
• The H-PCRF interacts with various network elements within the home network, including the Service Delivery Platform (SDP) and subscriber databases.
• Security measures are crucial to ensure the integrity and confidentiality of policy and charging information exchanged with the Visited PLMN's PCRF.

Comparison with V-PCRF (Visited PCRF):

Conclusion:

H-PCRF plays a vital role in modern mobile network architectures, particularly for roaming services. It ensures consistent policy enforcement, efficient charging, and a seamless user experience for roaming subscribers by collaborating with the PCRF of the Visited PLMN. As mobile network technologies evolve, H-PCRF will continue to be a key element in managing roaming services and ensuring a consistent user experience across different network operators.