HARQ Entity Reset for Component Carrier Reconfiguration

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Solution Overview

Problem

In LTE-Advanced wireless communication systems, there is no clear specification for resetting HARQ entities when component carriers are reconfigured, added, or removed, leading to data transmission failures due to mismatched new data indicators between user equipment and the network.

Innovation Solution

A method for resetting HARQ entities in a wireless communication device operating with multiple component carriers, where the HARQ entity associated with the reconfigured, added, removed, activated, or deactivated component carrier is specifically reset, with new data indicators set to default values and buffers managed accordingly, ensuring consistent context maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the UE resets all HARQ entities in multiple component carriers based on MAC entity reset mechanism, then the system structure becomes simple, but data transmission fails due to mismatched new data indicators between UE and eNB

Engineering Contradiction:
Improvesystem structureVSAvoiddata transmission
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the HARQ entity reset operation by component carrier. Instead of resetting all HARQ entities uniformly when MAC entity is reset, the invention selectively resets only the HARQ entity associated with the reconfigured component carrier while maintaining other HARQ entities in their current state. This segmentation resolves the contradiction by preserving transmission reliability for unaffected carriers while simplifying the overall reset mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by making the reset behavior carrier-specific. Each component carrier has its own HARQ entity that is reset independently based on whether that specific carrier is being reconfigured. This allows different parts of the system to have different states during reset, ensuring that only the affected carrier experiences reset while others maintain their transmission context, thus preventing data transmission failures.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the UE sets new data indicators to default value for all HARQ processes in all component carriers, then the reset mechanism is uniform, but new data indicators for other component carriers become mismatched between UE and eNB

Engineering Contradiction:
Improvereset mechanismVSAvoidnew data indicator alignment
Core Design Contradiction:
Ease of manufactureVSLoss of information

Solution Approach 1:

The patent segments the NDI reset operation by component carrier. Instead of applying a uniform reset to all carriers, the invention segments the reset action to only affect the specific carrier being reconfigured. This segmentation preserves NDI alignment information for other carriers, preventing the loss of synchronization between UE and eNB for ongoing transmissions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the reset operation from a global scope and applies it only to the specific HARQ entity associated with the reconfigured component carrier. By taking out the reset action from the universal MAC entity reset context and placing it within the specific carrier's HARQ entity, the invention prevents unnecessary NDI resets that would cause mismatching with the network.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the UE maintains HARQ entity context for reconfigured component carrier, then data transmission continues smoothly, but the reset mechanism becomes more complex

Engineering Contradiction:
Improvedata transmission continuityVSAvoidreset mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by making the reset behavior carrier-specific. Each component carrier has its own HARQ entity that is reset independently based on whether that specific carrier is being reconfigured. This allows different parts of the system to have different states during reset, ensuring that only the affected carrier experiences reset while others maintain their transmission context, thus preventing data transmission failures.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2518926B1Method of hybrid automatic repeat request entity handling and communication device thereof
Publication Date: 2014.10.29 HTC CORP
  • EP2518926B1 patent drawingFigure 1
  • EP2518926B1 patent drawingFigure 2
  • EP2518926B1 patent drawingFigure 3

AI summary

A method of hybrid automatic repeat request (HARQ) entity handling for a communication device capable of receiving and transmitting on a plurality of component carriers in a wireless communication system is disclosed. The method comprises resetting a HARQ entity associated to a component carrier of the plurality of component carriers when a component carrier configuration associated to the component carrier is changed.