Sidelink MAC Reset Coordination for Continuous PC5 Communication

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Solution Overview

Problem

Existing wireless communication systems face challenges in managing medium access control (MAC) resets, particularly in sidelink interfaces, leading to communication interruptions and increased signaling overhead during MAC resets of Uu and sidelink interfaces.

Innovation Solution

A method and apparatus for a terminal to independently manage MAC resets of both Uu and sidelink interfaces, allowing data transmission and reception to continue through either interface during a MAC reset, thereby preventing communication interruptions and reducing signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a MAC reset is performed in sidelink communication, then the MAC entity can be reused after failure, but the reset process blocks the PDCP entity and causes data retransmission delays

Engineering Contradiction:

ImproveMAC entity reuse capabilityVSAvoiddata retransmission delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the reset process by introducing a separate reset indication mechanism that decouples the MAC reset operation from the PDCP data processing flow. The reset indication information is transmitted separately to the second UE, allowing the PDCP entity to continue processing data independently while the MAC entity performs the reset operation, thus eliminating the blocking effect and reducing retransmission delays.

Inventive Principle:

Principle #1Segmentation

2Device complexity

If reset indication information is not transmitted to the second UE, then the procedure is simpler, but the second UE cannot properly perform sidelink communication after MAC reset

Engineering Contradiction:

Improvereset procedure complexityVSAvoidsidelink communication capability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces reset indication information as an intermediary element that carries the reset status from the first UE to the second UE. This intermediary mechanism enables the second UE to understand and respond appropriately to the MAC reset operation without requiring complex direct coordination protocols, thus maintaining communication reliability while keeping the procedure manageable.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Speed

If the MAC entity is reset without proper indication to the second UE, then the reset operation is faster, but data packets may be lost due to lack of coordination

Engineering Contradiction:

Improvereset operation speedVSAvoiddata packet loss

Core Design Contradiction:

SpeedVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the first UE transmits reset indication information to the second UE after performing the MAC reset. This feedback loop ensures that the second UE is aware of the reset operation and can adjust its data processing accordingly, preventing data packet loss while maintaining relatively fast reset operation speeds through efficient information exchange.

Inventive Principle:

Principle #23Feedback

Data Source

PatentEP4138509B1Apparatus and method for processing sidelink mac reset in wireless communication system

Publication Date: 2026.04.29 SAMSUNG ELECTRONICS CO LTD

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AI summary

In a wireless communication system according to an embodiment of the present disclosure, a method of a first terminal for sidelink communication may include receiving, from a second terminal, a sidelink radio resource control (RRC) reconfiguration message including sidelink reset configuration information, releasing a sidelink radio bearer for PC5-RRC connection with the second terminal, and resetting a medium access control (MAC) entity of a sidelink for the PC5-RRC connection with the second terminal.