NR V2X Sidelink DRX Reset Handling for MAC CE Cancellation

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Solution Overview

Problem

In wireless communication systems, unnecessary generation and signaling of DRX command MAC CEs occur during sidelink interface MAC resets, leading to inefficient resource utilization and increased latency.

Innovation Solution

Implementing a method and apparatus to cancel triggered SL DRX command MAC CE reporting based on a requested MAC reset for PC5-RRC connection, thereby optimizing DRX timer management and reducing unnecessary monitoring of PSCCH.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the UE receives a request for sidelink interface MAC reset and stops the DRX timer, then the UE can efficiently manage DRX state, but unnecessary DRX command MAC CEs are generated and signaled

Engineering Contradiction:

ImproveDRX state management efficiencyVSAvoidunnecessary DRX command MAC CE generation and signaling

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by having the UE cancel the triggered SL DRX command MAC CE reporting before the MAC reset is completed. The UE checks whether to cancel the reporting based on the MAC reset request, and if cancellation is needed, it does so in advance to prevent unnecessary DRX command MAC CE generation and signaling while still allowing proper DRX timer management.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the UE stops monitoring PSCCH during MAC reset, then resource utilization is improved, but latency increases due to unnecessary monitoring interruptions

Engineering Contradiction:

Improveresource utilizationVSAvoidlatency from monitoring interruptions

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent applies feedback by having the UE determine whether to cancel SL DRX command MAC CE reporting based on feedback from the MAC reset request. The UE monitors the MAC reset state and uses this feedback information to decide whether to prevent DRX timer stops and PSCCH monitoring, thereby optimizing both resource utilization and latency performance.

Inventive Principle:

Principle #23Feedback

3Ease of operation

If DRX command MAC CE is included in MAC PDU, then DRX timer can be stopped, but unnecessary MAC PDUs are generated and signaled

Engineering Contradiction:

ImproveDRX timer controlVSAvoidunnecessary MAC PDU generation and signaling

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies the taking out principle by extracting and removing the unnecessary SL DRX command MAC CE from the MAC PDU when the UE determines that the MAC reset request requires cancellation of reporting. This selective removal prevents unnecessary MAC PDU generation and signaling while preserving the essential DRX timer control functionality through alternative means.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS20260046956A1Method and apparatus for performing radio communication related to mac reset in NR v2x

Publication Date: 2026.02.12 LG ELECTRONICS INC

AI summary

A method for performing wireless communication by a first device and an apparatus supporting the same are proposed. For example, the first device may obtain an SL DRX configuration including information related to an SL DRX cycle and information related to a timer for active time. For example, the timer for active time may include at least one of an SL DRX on-duration timer or an SL DRX inactivity timer. For example, the first device may trigger SL DRX command MAC CE reporting related to the PC5-RRC connection. For example, the first device may cancel the triggered SL DRX command MAC CE reporting, based on an MAC reset for the PC5-RRC connection being requested.