Radio Link Failure Reporting for Mobility Parameter Adjustment

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Solution Overview

Problem

Wireless communication networks face challenges in determining and reporting radio link failures (RLF) during handover processes, leading to suboptimal mobility performance due to the serving access point's inability to independently detect RLF events.

Innovation Solution

Implementing a system where the target access point determines RLF events and reports them to the serving access point, allowing the network to adjust mobility parameters based on this information to improve handover performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the serving access point relies on its own measurements to detect radio link failure, then the detection process is simple, but the serving access point cannot independently determine RLF events during handover

Engineering Contradiction:
ImproveRLF detection accuracyVSAvoiddetection mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The target access point acts as an intermediary that detects RLF events during handover and reports them to the serving access point. This mediator approach enables accurate RLF detection without requiring the serving access point to directly monitor radio conditions during the handover process, resolving the contradiction between detection accuracy and system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the network does not track RLF events, then the system operation is simple, but mobility performance is suboptimal due to inability to adjust parameters

Engineering Contradiction:
Improvemobility performanceVSAvoidparameter tracking complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system implements feedback by having the target access point report RLF events to the serving access point, which then uses this information to adjust mobility parameters. This feedback loop enables continuous optimization of mobility performance based on actual handover outcomes, resolving the contradiction between improved productivity and increased complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary actions by tracking and analyzing RLF events over time, allowing the network to proactively adjust mobility parameters before performance degradation occurs. This preventive approach improves mobility performance by enabling parameter optimization based on historical failure patterns.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the target access point reports RLF events to the serving access point, then handover performance can be improved through parameter adjustment, but additional communication overhead is introduced

Engineering Contradiction:
Improvehandover reliabilityVSAvoidcommunication overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The system extracts only the critical RLF event information from the complex handover process and transmits it separately to the serving access point. This extraction approach enables improved handover reliability through parameter adjustment while minimizing communication overhead by transmitting only essential failure event data rather than complete handover process information.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2359626B1Mobility management based on radio link failure reporting
Publication Date: 2019.12.25 QUALCOMM INC
  • EP2359626B1 patent drawingFigure 1
  • EP2359626B1 patent drawingFigure 2
  • EP2359626B1 patent drawingFigure 3

AI summary

A communication node determines that radio link failure occurred during connected state mobility of an access terminal and reports the radio link failure to another communication node. For example, a target access point may determine that radio link failure occurred during handover of an access terminal and send a radio link failure report message to the access point that was previously serving the access terminal or to some other node (e.g., a network node). In the first case, the serving access point may adjust mobility parameters based on this radio link failure information and, optionally, other reported radio link failure information. In the second case, the other node may send a radio link failure report message to the serving access point, or the other node may adjust mobility parameters based on this radio link failure information (and, optionally, other reported radio link failure information) and send the adjusted mobility parameters to the serving access point.