Sidelink LBT Failure Reporting via MAC CE on Unlicensed Spectrum

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Solution Overview

Problem

There is a lack of effective means for reporting SL consistent LBT failure in Sidelink communication on unlicensed spectrum, which affects communication efficiency and service operation.

Innovation Solution

A terminal sends indication information to a network device to report the state of SL consistent LBT failure on a physical resource, using MAC CE to indicate the failure status of resource pools or resource block sets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If Sidelink communication uses unlicensed spectrum with LBT mechanism, then communication capacity and speed are improved, but LBT failure reporting capability deteriorates (no effective means for reporting SL consistent LBT failure)

Engineering Contradiction:
Improvecommunication capacityVSAvoidLBT failure reporting capability
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent applies universality by enabling the terminal to report SL consistent LBT failure information using the existing uplink communication channel with the network device. This allows the same communication infrastructure to serve dual purposes: both regular data transmission and failure reporting, thereby resolving the information loss issue without requiring separate dedicated reporting channels.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements feedback by establishing a reporting mechanism where the terminal sends LBT failure information back to the network device. This feedback loop enables the network device to receive real-time status updates about LBT failures, allowing it to adjust resource allocation and improve overall system performance, thus addressing the lack of reporting capability.

Inventive Principle:
Principle #23Feedback

2Reliability

If LBT failure reporting is implemented, then communication reliability is improved, but system complexity increases (requiring new indication information and reporting mechanisms)

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidreporting mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent reduces complexity by making the existing uplink channel serve multiple functions - both data transmission and failure reporting. This avoids the need for separate dedicated reporting infrastructure, thereby improving reliability while minimizing the increase in system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The terminal autonomously generates and sends LBT failure indication information when failures occur, without requiring complex external triggering mechanisms. This self-service approach simplifies the overall system architecture while ensuring reliable failure reporting, as the terminal independently manages its own failure notification.

Inventive Principle:
Principle #25Self-service

3Productivity

If SL consistent LBT failure state is reported, then resource utilization is improved, but information processing load increases (terminal and network device must process failure states)

Engineering Contradiction:
Improveresource utilizationVSAvoidinformation processing load
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the essential LBT failure state information for reporting, rather than transmitting complete detailed logs or continuous status streams. By taking out only the critical failure indication, the system improves resource utilization through better awareness while minimizing the information processing load on both terminal and network device.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies partial action by reporting LBT failure information only when actual failures occur, rather than continuously monitoring and reporting all channel access attempts. This event-driven approach optimizes resource utilization by providing necessary failure data while significantly reducing the processing load compared to continuous monitoring.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4708741A1Information sending method and apparatus
Publication Date: 2026.03.11 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4708741A1 patent drawingFigure 1~5
  • EP4708741A1 patent drawingFigure 6~10
  • EP4708741A1 patent drawingFigure 11~14

AI summary

Disclosed in embodiments of the present disclosure are an information sending method and an apparatus, applicable to the technical field of communications. The method executed by a terminal device comprises: sending indication information to a network device, wherein the indication information is used for indicating a physical resource sidelink (SL) continuous listen-before-talk (LBT) failure state. According to the method provided by the present disclosure, the terminal device can be supported to report the physical resource SL continuous LBT failure state, so as to inform the network device whether a physical resource triggers an SL continuous LBT failure, thereby improving the communication efficiency of the SL communication of the terminal device, and ensuring a normal communication service.