QoS-Based Beam Selection for Make-Before-Break Handover

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently managing beams during make-before-break (MBB) handovers, particularly in scenarios where the transmission times of signals from different cells overlap, leading to difficulties in determining which signal to receive and maintain connectivity.

Innovation Solution

The proposed solution involves prioritizing transmit beams from multiple cells and selecting a receive beam based on communication metrics such as quality of service (QoS), latency, reliability, and priority requirements. This allows the user equipment (UE) to determine which signal to receive by comparing the priority of communication metrics associated with signals from different cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE receives signals from both source and target cells during MBB handover, then connectivity is maintained, but beam management complexity increases due to overlapping transmission times

Engineering Contradiction:
Improveconnectivity maintenanceVSAvoidbeam management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring the UE with multiple receive beams before the handover occurs. The UE is configured with a first receive beam for the source cell and a second receive beam for the target cell in advance, so that when overlapping transmissions occur during handover, the UE can immediately use the pre-configured beams without needing to dynamically select or switch beams during the critical handover period. This resolves the complexity by preparing the beam configuration beforehand.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the UE uses different receive beams for source and target cells, then signal reception is optimized, but determining which signal to receive becomes difficult when transmission times overlap

Engineering Contradiction:
Improvesignal reception optimizationVSAvoidsignal selection difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies feedback by having the UE report beam measurement information to the network. The UE measures qualities of the signals received through different beams and reports this information back to the network entity. This feedback mechanism enables the network to understand which beams are performing best and can use this information to make informed decisions about beam selection and handover timing, thereby resolving the difficulty of determining which signal to receive when transmissions overlap.

Inventive Principle:
Principle #23Feedback

3Reliability

If beam switching is performed during handover, then connectivity is maintained, but latency increases due to beam switching time

Engineering Contradiction:
Improveconnectivity maintenanceVSAvoidhandover latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-configuring multiple receive beams in the UE before the handover occurs. The UE is configured with the appropriate receive beams for both source and target cells in advance, eliminating the need for dynamic beam switching during the handover process. This pre-configuration allows the UE to immediately receive signals from both cells during overlapping transmission periods without experiencing beam switching latency, thereby maintaining connectivity while minimizing handover time.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If the UE monitors multiple communication metrics for beam prioritization, then signal selection is optimized, but processing complexity increases

Engineering Contradiction:
Improvesignal selection optimizationVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by having the UE monitor and evaluate a specific set of communication metrics that are most relevant for beam selection during handover. Rather than monitoring all possible metrics, the patent identifies and focuses on the key metrics (such as signal quality, beam direction, and transmission timing) that directly impact handover performance. This selective monitoring approach optimizes signal selection while minimizing the processing complexity that would result from monitoring and processing every possible metric.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4029310B1Quality of service (QOS) based beam determination for make-before-break (MBB) handover
Publication Date: 2025.04.02 QUALCOMM INC
  • EP4029310B1 patent drawingFigure 1
  • EP4029310B1 patent drawingFigure 2
  • EP4029310B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure provide techniques for beam management for make-before-break (MBB) handover. A method that may be performed by a user equipment (UE) includes establishing a first cell connection with a first base station (BS) while maintaining an existing second cell connection with a second BS, and determining that a first transmission time of a first signal transmitted by the first BS is less than a threshold time duration from a second transmission time of a second signal transmitted by the second BS. In some examples, the first signal is associated with one or more first communication metrics and the second signal is associated with one or more second communication metrics, wherein each of the one or more first communication metrics and the one or more second communication metrics comprise one or more quality of service (QoS) metrics.