Sidelink Resource Reselection for Continuous LBT Failure Recovery

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Solution Overview

Problem

There is a lack of effective solutions for handling sidelink (SL) consistent listen before talk (LBT) failures in unlicensed spectrum scenarios, which hampers communication efficiency in applications such as vehicle-to-everything (V2X) and intelligent driving.

Innovation Solution

A method and apparatus for handling SL consistent LBT failures by performing resource reselection when triggered on a resource block set (RB set), ensuring timely recovery of sidelink communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If listen before talk (LBT) is performed in unlicensed spectrum for sidelink communication, then spectrum utilization is improved, but communication reliability deteriorates due to consistent LBT failures

Engineering Contradiction:
Improvespectrum utilizationVSAvoidcommunication reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the resource block set into multiple individual resource blocks and further divides each resource block into multiple candidate resources. This segmentation allows the terminal to perform LBT failures detection at the resource block set level while maintaining the ability to identify and avoid specific failing resources, thereby resolving the contradiction between spectrum utilization and communication reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary detection of LBT failures by monitoring a counter value that tracks consecutive LBT failures on resource block sets. When the counter reaches a threshold, the system proactively triggers resource reselection before complete communication failure occurs, ensuring timely recovery and maintaining reliability while continuing to utilize the unlicensed spectrum.

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If resource reselection is performed upon detecting SL consistent LBT failures, then communication recovery time is reduced, but signaling overhead and processing complexity increase

Engineering Contradiction:
Improvecommunication recovery timeVSAvoidprocessing complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent implements a dynamic resource reselection mechanism where the decision to reselect resources is based on the real-time value of the LBT failure counter. The counter is dynamically incremented upon detecting LBT failures and reset when successful transmissions occur. This dynamic approach enables timely communication recovery while avoiding unnecessary resource reselection and reducing processing complexity by using a simple counter-based decision criterion.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4712660A1Method and apparatus for processing sidelink continuous listen-before-talk failure
Publication Date: 2026.03.18 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4712660A1 patent drawingFigure 1~4
  • EP4712660A1 patent drawingFigure 5~7
  • EP4712660A1 patent drawingFigure 8

AI summary

Disclosed in embodiments of the present disclosure are a method and apparatus for a sidelink (SL) continuous listen-before-talk (LBT) failure, applicable to systems such as Internet of vehicles, V2X, and V2V. The method comprises: when detecting that an SL continuous LBT failure is triggered on a resource block set (RB set), a terminal device performs resource reselection. By implementing the embodiments of the present disclosure, when detecting that an SL continuous LBT failure is triggered on an RB set, a terminal device can perform resource reselection, ensuring timely recovery of SL communication when the SL continuous LBT failure occurs in the terminal device, thereby improving the communication efficiency of the SL communication of the terminal device.