PCell SCell Link Failure Recovery Prioritization

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in resource utilization and link failure handling, particularly when both primary cell (PCell) and secondary cell (SCell) fail, lacking a consistent mechanism for managing these failures effectively.

Innovation Solution

The implementation of methods and apparatuses for detecting and recovering from link failures in PCell and SCell, prioritizing PCell recovery over SCell recovery when both fail, using techniques such as contention-free and contention-based RACH procedures, and managing link failure recovery timers to optimize resource allocation and communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If link failure recovery procedures are handled independently for PCell and SCell without prioritization, then both cells can attempt recovery simultaneously, but resource utilization efficiency deteriorates and system complexity increases due to conflicting recovery procedures

Engineering Contradiction:

Improvelink failure recoveryVSAvoidresource utilization efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system performs preliminary detection of link failures in both PCell and SCell, then preemptively establishes a prioritization scheme before recovery procedures begin. The UE detects failures, determines priority based on cell type (PCell > SCell), and initiates recovery in a predetermined sequence, preventing resource conflicts before they occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The recovery procedure is segmented into distinct phases: detection phase, priority determination phase, and execution phase. By dividing the recovery process into separate stages with clear boundaries, the system can manage multiple failures systematically without procedural conflicts, improving resource utilization.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If PCell recovery is prioritized over SCell recovery when both fail simultaneously, then network stability is improved, but SCell recovery time increases

Engineering Contradiction:

Improvenetwork stabilityVSAvoidSCell recovery time

Core Design Contradiction:

Stability of the object's compositionVSLoss of time

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

While PCell recovery is being executed, the system does not idle the SCell recovery process entirely. Instead, the SCell recovery procedure is held in a ready state with resources pre-allocated, allowing seamless transition and continuous progress, minimizing actual waiting time.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If multiple link failure recovery procedures are handled simultaneously without a consistent mechanism, then recovery coverage is improved, but device complexity increases and ease of operation deteriorates

Engineering Contradiction:

Improverecovery coverageVSAvoidrecovery mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a universal recovery management mechanism that handles both PCell and SCell failures through a single consistent framework. The UE uses a unified priority determination logic (PCell > SCell) and a standardized procedure selection process that works for any combination of cell failures, simplifying the overall system architecture.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The recovery mechanism dynamically adapts its behavior based on the specific failure scenario. The UE assesses the current state, determines which cells have failed, applies the prioritization rules accordingly, and executes the appropriate recovery sequence. This dynamic decision-making reduces complexity compared to having separate fixed procedures for each failure type.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3949677B1Link failure recovery procedures and apparatuses for a primary cell (PCELL) and a secondary cell (SCELL)

Publication Date: 2024.04.10 QUALCOMM INC

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AI summary

Wireless communications systems and methods related to handling link failures in a first cell and a second cell are provided. A wireless communication device can detect a first link failure associated with a first cell and can detect a second link failure associated with a second cell. Additionally, the wireless communication device can perform a link failure recovery procedure. This may include prioritizing a first link failure recovery for the first cell over a second link failure recovery for the second cell. Other aspects and features are also claimed and described.