Master Cell Group Failure Recovery in Dual Connectivity Wireless Devices

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Solution Overview

Problem

In dual connectivity wireless devices, radio link failures can disrupt data communication, and existing technologies lack efficient methods for recovering from master cell group failures without necessitating full radio resource control re-establishment, leading to potential data interruptions.

Innovation Solution

Implementing a method where a wireless device can continue using a secondary cell group link during master cell group link failure, allowing for recovery of the master cell group link without requiring a full radio resource control re-establishment, thereby minimizing data interruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full radio resource control re-establishment procedure is performed upon master cell group link failure, then the link reliability is restored, but data communication interruptions occur and service continuity is broken

Engineering Contradiction:

Improvelink reliabilityVSAvoiddata communication interruption time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the cell group into master cell group and secondary cell group, allowing independent failure handling. When master cell group link fails, the secondary cell group continues operating, enabling partial service continuity. The recovery procedure is segmented into failure detection, secondary cell group takeover, and gradual master cell group recovery, avoiding complete service interruption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The secondary cell group acts as an intermediary during master cell group failure. It temporarily assumes the role of providing data communication services while the master cell group is being recovered. This intermediary mechanism prevents complete service breakdown and reduces interruption time.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a full radio resource control re-establishment procedure is performed, then the connection is restored, but the complexity of the recovery process increases

Engineering Contradiction:

Improveconnection restorationVSAvoidrecovery procedure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The recovery procedure is segmented into multiple stages: failure detection stage, secondary cell group activation stage, and master cell group recovery stage. This segmentation simplifies each individual stage while maintaining overall reliability, avoiding the need for a single complex all-or-nothing re-establishment procedure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic recovery strategies where the system adapts its recovery approach based on the failure state. If the master cell group can be quickly recovered, a simplified procedure is used. If recovery takes longer, the secondary cell group maintains services dynamically, reducing the apparent complexity for the user.

Inventive Principle:

Principle #15Dynamics

3Productivity

If the master cell group link is immediately re-established, then service continuity is maintained, but the stability of the recovered link may be compromised

Engineering Contradiction:

Improveservice continuityVSAvoidlink stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The secondary cell group is pre-configured and pre-activated as a backup before master cell group failure occurs. When failure happens, the preliminary preparation allows immediate takeover, maintaining service continuity. The gradual recovery of the master cell group then stabilizes the link composition over time.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system provides beforehand cushioning by having the secondary cell group ready to absorb the impact of master cell group failure. This cushioning mechanism prevents sudden service disruption and allows stable, gradual transition during recovery, protecting against link instability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS11564136B2Master cell group failure recovery for dual connectivity wireless devices

Publication Date: 2023.01.24 APPLE INC

AI summary

Apparatuses, systems, and methods for a wireless device to perform master cell group failure recovery in a dual connectivity cellular communication system. The wireless device may establish a first wireless link to a cellular network via a first cell group. The first cell group may be configured as a master cell group for the wireless device. The wireless device may establish a second wireless link to the cellular network via a second cell group. The second cell group may be configured as a secondary cell group for the wireless device. The wireless device may determine that link failure for the first wireless link has occurred. The wireless device may perform master cell group link failure recovery using the second wireless link based at least in part on the link failure for the first wireless link.