RIC-Based Stale UE Context Detection in O-RAN

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Solution Overview

Problem

In 5G networks, there is a need for an improved system and method to manage resource allocation mismatches, particularly for UE contexts, which can lead to stale contexts and resource exhaustion, causing critical service outages.

Innovation Solution

The proposed solution utilizes an RIC-based technique to detect and clean up stale RAN resources. This involves periodic polling of RAN nodes, telemetry data analysis, performance measurement counters, and resource status reporting to identify and correct mismatches in UE contexts across different RAN nodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If resource allocation is managed across distributed RAN nodes without centralized coordination, then network autonomy and distributed operation are improved, but resource allocation mismatches and stale UE contexts occur leading to service outages

Engineering Contradiction:
Improvedistributed operationVSAvoidservice continuity
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the RIC receives resource allocation information from multiple RAN nodes, analyzes mismatches, and sends correction commands back to the nodes. This closed-loop feedback system enables autonomous detection and resolution of stale UE contexts while maintaining distributed operation, thus resolving the contradiction between distributed autonomy and service reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The RIC acts as an intermediary between distributed RAN nodes, coordinating resource allocation and detecting mismatches. This intermediary layer enables centralized coordination without direct node-to-node communication, allowing distributed nodes to operate autonomously while preventing resource allocation conflicts that would compromise service continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If periodic polling and telemetry analysis are implemented to detect stale UE contexts, then detection accuracy is improved, but signaling overhead and network load increase

Engineering Contradiction:
Improvestale context detection accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The system performs preliminary actions by configuring RAN nodes to report resource allocation information at specific events (UE context release, handover completion) before stale contexts actually occur. This event-driven reporting reduces the need for continuous periodic polling, maintaining high detection accuracy while minimizing signaling overhead and energy consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic polling at optimized intervals rather than continuous monitoring. The RIC periodically requests resource allocation status from RAN nodes at configurable time intervals, balancing detection accuracy with signaling overhead. This periodic action reduces network load compared to continuous monitoring while still effectively identifying stale UE contexts.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4557807A1Method to detect stale ues in different ran nodes
Publication Date: 2025.05.21 MAVENIR SYST INC
  • EP4557807A1 patent drawingFigure 1
  • EP4557807A1 patent drawingFigure 2
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AI summary

A method for detecting stale UEs in O-RAN systems based on combining information derivable from the Radio Intelligent Controller consisting in a radio intelligent controller (RIC) polling a centralized unit control plane (CU-CP), a centralized unit user plane (CU-UP), and a distributed unit (DU) to receive information regarding allocated RAN resources associated with a user equipment (UE); and correlating, by the RIC, the received information regarding the allocated RAN resources associated with the UE to determine whether the CU-CP, CU-UP and DU are in sync with respect to the allocated RAN resources associated with the UE. A discrepancy in the allocated RAN resources among the CU-CP, CU-UP and DU indicates stale RAN resource allocation by at least one of the CU-CP, CU-UP and DU.