PCRF Failover via Shared Database for Policy Control

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Solution Overview

Problem

Current Policy and Charging Control (PCC) architectures in telecommunication networks lack efficient failover mechanisms and scalability without increasing complexity and equipment costs, particularly in handling PCRF failures and session management across multiple PCRFs.

Innovation Solution

Implementing a method where multiple PCRFs share a common database to store and retrieve session information, allowing seamless failover and load balancing, with each PCRF acting as a stateless frontend for policy decision-making while the database manages session data, enabling efficient handling of IP-CAN sessions across network nodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single PCRF is used for policy decision-making, then the system is simple to manage, but the system lacks reliability and cannot provide failover mechanisms

Engineering Contradiction:

Improveservice continuity during PCRF failureVSAvoidPCC architecture complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system segments the PCRF functionality into multiple independent PCRF instances (first PCRF, second PCRF) that share a common database. This segmentation allows individual PCRFs to fail without affecting the entire system, as other PCRFs can take over using the shared database, thereby improving reliability while maintaining manageable complexity through modular deployment

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A common shared database is introduced as an intermediary between multiple PCRFs and the PCEF. This database acts as a mediator that stores session information and policy data, enabling any PCRF to retrieve necessary information and make policy decisions, thus providing failover capability without requiring complex direct peer-to-peer communication between PCRFs

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If multiple PCRFs are deployed for load balancing and scalability, then the system can handle increased loads, but the complexity of session management across PCRFs increases

Engineering Contradiction:

Improvesession handling capacityVSAvoidsession management complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The common database serves multiple functions simultaneously: it stores session information, maintains policy data, enables failover, and supports load balancing across multiple PCRFs. This universal repository allows any PCRF to handle any session by querying the database, providing scalability and high productivity while keeping session management relatively simple through a unified access interface

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system changes the state management parameter from stateful (each PCRF maintaining its own session state) to stateless (PCRFs querying external state from the common database). This parameter change allows multiple PCRFs to handle sessions without complex state synchronization, as each PCRF independently retrieves current session information from the database, thereby improving productivity while managing complexity

Inventive Principle:

Principle #35Parameter changes

3Reliability

If stateful PCRF solutions are used to maintain session information locally, then failover is simplified, but the equipment costs and complexity increase

Engineering Contradiction:

Improvefailover capabilityVSAvoidequipment cost and implementation complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of each PCRF maintaining its own complete copy of session information (which would require expensive redundant hardware and complex synchronization), the system uses a single shared database that all PCRFs access. This copying approach provides failover capability by allowing any PCRF to retrieve session information from the shared database, achieving reliability while reducing equipment costs and implementation complexity

Inventive Principle:

Principle #26Copying

Data Source

PatentUS9735971B2High-availability, scalable policy and charging control systems, and methods therefor

Publication Date: 2017.08.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

In a method carried out by a first and second policy and charging rules functions (PCRF) (201, 202), the first PCRF receives (s10), from a policy and charging enforcement function (PCEF) (100), an IP-CAN session establishment indication, determines (s20) first policy decision information, causes (s30) a database (300) accessible by both PCRFs to store, in association with a session identifier, session information comprising the session data and the first policy decision information; and provides (s40), to the PCEF, the first policy decision information. Later, the second PCRF receives (s50), from the PCEF, a session modification indication, obtains (s60) therefrom the session identifier, retrieves (s70), from the database, the session information, determines (s80) second policy decision information; causes (s90) the database to store session information comprising the modified session data and second policy decision information; and provides (s100), to the PCEF, the second policy decision information. The invention also relates to a system putting into practice such method.