Sidelink Relay MAC-CE Activation Timing

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently activating media access control (MAC) control elements (CEs) transmitted over sidelink relays, particularly in ensuring reliable and timely activation of commands in sidelink communication scenarios.

Innovation Solution

A method and apparatus for activating a MAC-CE transmitted over a sidelink relay by waiting for an activation time period, which involves receiving an activation request in a first MAC-CE relayed from a second UE, transmitting a second MAC-CE with an activation response to the third UE, and activating the command after transmitting the activation response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If MAC-CE activation is performed over sidelink relay without waiting time, then activation speed is improved, but activation reliability deteriorates

Engineering Contradiction:
Improveactivation speedVSAvoidactivation reliability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent introduces an activation time period (e.g., 3ms) that the receiving UE waits before activating the command. This preliminary waiting period allows the network to send cancellation indications if needed, ensuring that activation only occurs when confirmed appropriate, thus resolving the contradiction between fast activation and reliable activation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If activation time period is extended to ensure reliability, then activation reliability is improved, but activation latency increases

Engineering Contradiction:
Improveactivation reliabilityVSAvoidactivation latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent defines specific parameter values for the activation time period (e.g., 3ms) and allows the network to configure this parameter dynamically. By optimizing this time parameter, the system achieves sufficient reliability for cancellation indications while minimizing unnecessary delay, thus resolving the contradiction between reliability and latency.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If MAC-CE relay mechanism is simplified for faster processing, then processing efficiency is improved, but message delivery reliability deteriorates

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidmessage delivery reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the receiving UE sends an acknowledgment (ACK) for the received MAC-CE, and the network can send cancellation indications. This feedback loop ensures that relayed messages are properly delivered and can be cancelled if needed, resolving the contradiction between simplified processing and reliable delivery.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4189886B1Activating sidelink relay mac-ce
Publication Date: 2025.04.16 QUALCOMM INC
  • EP4189886B1 patent drawingFigure 1
  • EP4189886B1 patent drawingFigure 2A~2D
  • EP4189886B1 patent drawingFigure 3

AI summary

The apparatus of wireless communication may be a UE configured to activate a MAC-CE transmitted over an SL relay after waiting a time period by receiving an activation request for a command in association with a third UE in a first MAC-CE relayed from a second UE, transmitting, to the second UE, a second MAC-CE including an activation response to the third UE in response to the activation request, and activating the command after transmitting the activation response. The UE may wait a time period after transmitting the activation response before activating the command. The UE may receive an HARQ ACK from the third UE in response to the transmitted activation response or an HARQ ACK from the second UE in response to the transmitted activation response, and wait a time period after receiving the HARQ ACK before activating the command.