5G PCF Fallback via Secondary Policy Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing 5G core networks face significant degradation in user experience when a primary Policy Control Function (PCF) fails, often resulting in session dropout or transfer to less advanced core networks.
Innovation Solution
Implementing a secondary PCF with pre-generated policies and a setup entity to manage communication between session management functions and both primary and secondary PCFs, ensuring seamless fallback and policy propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single primary PCF is used for policy control in 5G core networks, then device complexity is reduced, but reliability deteriorates when the primary PCF fails
Solution Approach 1:
The patent applies preliminary action by pre-configuring a secondary PCF with backup policy rules before the primary PCF fails. The secondary PCF is prepared in advance with the necessary policy control capabilities, allowing it to immediately take over when the primary PCF becomes unavailable, thus improving reliability without requiring complex real-time coordination during failure events.
Solution Approach 2:
The patent introduces an intermediary mechanism (the setup entity or SMF) that mediates between the primary and secondary PCFs. This intermediary manages the fallback process by detecting primary PCF unavailability and redirecting session management functions to the secondary PCF, thereby improving reliability while keeping the complexity management centralized rather than distributed across multiple PCFs.
2Reliability
If multiple PCFs are configured for redundancy, then reliability improves, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the policy control function into distinct primary and secondary instances, each with specific responsibilities. The primary PCF handles active session management while the secondary PCF maintains backup policy rules. This segmentation allows for simplified policy management where each PCF operates independently with well-defined roles, reducing the complexity of coordinating multiple active policy systems.
Solution Approach 2:
The patent uses copying by creating a replica (secondary PCF) of the primary PCF with identical policy control capabilities. The secondary PCF receives copies of policy rules from the primary PCF during normal operation, ensuring that the backup system is fully synchronized without requiring complex real-time coordination. This copying approach improves reliability while maintaining manageable complexity through standardized replication processes.
3Adaptability or versatility
If real-time coordination between multiple entities is implemented, then adaptability improves, but device complexity and processing overhead increase
Solution Approach 1:
The patent applies preliminary action by pre-establishing policy rule copies in the secondary PCF before any failure occurs. This eliminates the need for real-time coordination during failure events, as the secondary PCF already possesses the necessary policy information to take over immediately. The setup entity can simply redirect traffic without requiring complex negotiation or coordination protocols.
Solution Approach 2:
The patent implements self-service by enabling the secondary PCF to autonomously take over policy control functions when the primary PCF fails. The secondary PCF monitors its own operational status and can independently assume the primary PCF's responsibilities without requiring continuous coordination or control from other network entities. This self-service capability improves adaptability to failures while significantly reducing communication overhead and coordination complexity.
Data Source
AI summary
Systems, methods, and devices can be utilized for policy control function (PCF) fallback during the set up of a session utilizing a 5th Generation (5G) core network. An example method includes receiving, from a session management function (SMF), a request for a policy corresponding to a session. The request includes a first policy identifier corresponding to a first policy control function (PCF). The example method further includes determining that the first PCF is unavailable, generating a modified request by replacing the first policy identifier with a second policy identifier in the request. The second policy identifier corresponds to a second PCF. The example method also includes transmitting, to the second PCF, the modified second request.