Sidelink SL-DRX Timing in Unlicensed Bands Using COT

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Solution Overview

Problem

In sidelink communication using an unlicensed band, the configuration of SL-DRX (Sidelink DRX) on-period and the resulting interruptions need to be defined to manage channel occupancy effectively.

Innovation Solution

The SL-DRX on-period is configured considering COT (Channel Occupancy Time) to define interruptions and optimize channel access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If SL-DRX on-period is configured for sidelink communication in unlicensed band, then channel occupancy management is improved, but communication interruptions occur

Engineering Contradiction:
Improvechannel occupancy management efficiencyVSAvoidcommunication continuity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by configuring the SL-DRX on-period in advance before actual communication occurs. The interruption timing is pre-defined based on COT (Channel Occupancy Time) parameters, allowing the terminal to prepare for expected interruptions beforehand. This enables the terminal to manage channel occupancy efficiently while minimizing the impact of interruptions on communication continuity.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by moving object

If SL-DRX is enabled for power saving, then energy consumption is reduced, but channel access efficiency deteriorates

Engineering Contradiction:
Improveterminal power consumptionVSAvoidchannel access efficiency
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent implements periodic action through SL-DRX (Sidelink Discontinuous Reception) operation, where the terminal periodically activates and deactivates its receiver according to configured on-periods. This periodic operation allows the terminal to save energy during off-periods while maintaining the ability to access the channel efficiently during on-periods. The COT-based interruption definition ensures that periodic activation aligns with actual communication needs, balancing power saving and channel access efficiency.

Inventive Principle:
Principle #19Periodic action

3Duration of action of stationary object

If COT sharing is implemented, then channel occupancy time is extended, but interruption duration increases

Engineering Contradiction:
Improvechannel occupancy timeVSAvoidinterruption duration
Core Design Contradiction:
Duration of action of stationary objectVSLoss of time

Solution Approach 1:

The patent applies local quality by defining interruptions at specific local points within the COT (Channel Occupancy Time) period rather than uniformly throughout. The interruption timing is locally defined based on SL-DRX on-period configuration, allowing extended COT sharing to benefit from increased channel occupancy time while limiting interruption impact to specific predetermined intervals. This localized approach to interruption management optimizes the balance between extended channel access and minimal disruption.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4648532A1Communication in SL-DRX-related unlicensed band
Publication Date: 2025.11.12 LG ELECTRONICS INC
  • EP4648532A1 patent drawingFigure 1
  • EP4648532A1 patent drawingFigure 2
  • EP4648532A1 patent drawingFigure 3

AI summary

An embodiment of the present disclosure provides a method by which a UE performs communication. The method comprises the steps of: performing SL-DRX on from deactivation to activation of SL-DRX; performing SL-DRX off from activation to deactivation of the SL-DRX after a specific time from a time point when the SL-DRX on is performed; measuring signal strength of a specific channel at the time point when the SL-DRX on is performed, wherein the specific channel is included in an unlicensed band; on the basis of a result of the measurement being less than or equal to a threshold value, transmitting a sidelink to another UE through the specific channel; and on the basis of the result of the measurement being less than or equal to the threshold value, determining a channel occupancy time for the specific channel, wherein the specific time is based on the channel occupancy time.