Sidelink HARQ RTT Timer Management for PSFCH Resource Association

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Solution Overview

Problem

In sidelink communications, terminals enter a sleep state if there is no active timer during the operation of the sidelink HARQ RTT timer, leading to inefficiencies and resource wastage.

Innovation Solution

A method and device for determining physical sidelink feedback channel (PSFCH) resources associated with a physical sidelink shared channel (PSSCH) to start or restart the sidelink HARQ RTT timer, even in cases of listen before talk (LBT) failures, thereby extending the terminal's sleep duration and conserving resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the terminal enters sleep state during sidelink HARQ RTT timer operation, then energy consumption is reduced, but communication responsiveness deteriorates

Engineering Contradiction:

Improveenergy consumptionVSAvoidcommunication responsiveness

Core Design Contradiction:

Use of energy by moving objectVSSpeed

Solution Approach 1:

The patent implements dynamic timer management where the sidelink HARQ RTT timer is selectively started or restarted based on PSFCH resource association. The terminal transitions between active and sleep states dynamically rather than maintaining a fixed state, allowing energy savings while ensuring timely wake-up when feedback is needed

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent performs preliminary determination of PSFCH resource association before entering sleep state. By pre-identifying which PSFCH resources are associated with PSSCH and configuring appropriate timers in advance, the terminal ensures it will wake up at the correct time to receive feedback without needing to remain continuously active

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the terminal remains active to handle LBT failures, then communication reliability is improved, but energy consumption increases

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses feedback mechanisms where the terminal determines PSFCH resource association and configures sidelink HARQ RTT timers based on this determination. The feedback from resource association analysis enables intelligent timer management that maintains reliability by ensuring timers are active when feedback is expected while allowing sleep when no feedback is anticipated

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent changes the operational parameters of the HARQ RTT timer based on PSFCH resource association status. When PSFCH resources are associated with PSSCH, the timer is started or restarted with specific timing parameters; when not associated, the terminal can enter sleep state, effectively changing the timer's operational state to match communication needs

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4615152A1Method for starting or restarting sidelink HARQ RTT timer, and apparatus

Publication Date: 2025.09.10 BEIJING XIAOMI MOBILE SOFTWARE CO LTD

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AI summary

The present invention provides a method for starting or restarting a sidelink HARQ RTT timer, and an apparatus, which can be applied to a mobile communication technology. The method comprises: determining a physical sidelink feedback channel (PSFCH) resource associated with a physical sidelink shared channel (PSSCH); starting or restarting the sidelink HARQ RTT timer for the PSFCH resource associated with the PSSCH. The method can achieve starting or restarting of the HARQ RTT timer when a plurality of PSFCH resources are introduced.