MAC CE Effective Time Alignment for NTN Transmission Delays

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Solution Overview

Problem

In Non-Terrestrial Networks (NTN) scenarios, the transmission delay between the UE and the base station is significant, leading to uncertainties in the effective time of MAC CE signaling configurations, which can result in failed configurations due to misalignment in understanding between the base station and the UE.

Innovation Solution

Determine the effective time of MAC CE signaling configurations by incorporating a preset time interval that accounts for transmission delays, including compensation durations for both the base station and the UE, using time interval indication information to ensure synchronized understanding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the base station determines the effective time of MAC CE signaling without considering transmission delay, then the determination process is simple and fast, but the configuration may fail to be taken into effect due to misalignment between base station and UE understanding

Engineering Contradiction:
Improveconfiguration success rateVSAvoidtime determination complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The base station performs preliminary calculation of the preset time interval (including transmission delay and compensation duration) before determining the effective time. This preliminary action ensures that the effective time is pre-calculated with proper delay compensation, preventing configuration failure while maintaining a systematic and manageable determination process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a preset time interval parameter that includes transmission delay and compensation duration, changing the time determination from a simple instantaneous calculation to a parameter-based calculated value. This parameter change ensures accurate alignment between base station and UE understanding of when the configuration takes effect.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the base station uses a preset time interval including transmission delay to determine effective time, then the configuration success rate improves, but the time determination process becomes more complex

Engineering Contradiction:
Improveconfiguration success rateVSAvoidtime for time determination
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The preset time interval is calculated in advance before the actual configuration determination. By performing this calculation preliminarily, the base station avoids repeated complex calculations during configuration processing, thus reducing the time loss while maintaining accurate effective time determination.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the base station and UE use the same method to determine effective time, then understanding alignment improves, but transmission delay causes uncertainty in the effective time

Engineering Contradiction:
Improveunderstanding alignmentVSAvoideffective time precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent incorporates compensation duration into the preset time interval, which is determined based on feedback about transmission delay characteristics. This feedback mechanism allows the base station to adjust the effective time calculation to account for actual transmission conditions, ensuring both alignment and precision.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the time determination parameter from a fixed value to a calculated preset time interval that includes transmission delay and compensation duration. This parameter change ensures that both base station and UE use the same calculated value, achieving understanding alignment while maintaining precision through proper delay compensation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4221031B1Method and apparatus for determining effective time, communication device, and storage medium
Publication Date: 2026.01.28 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4221031B1 patent drawingFigure 1~3
  • EP4221031B1 patent drawingFigure 4~6
  • EP4221031B1 patent drawingFigure 7~8

AI summary

Embodiments of the present disclosure relate to a method and apparatus for determining an effective time, a communication device, and a storage medium. The method comprises: determining a time after an elapse of a predetermined time interval following a time slot associated with transmission of medium access control control element (MAC CE) signaling to be an effective time of a configuration carried by the MAC CE signaling, wherein the predetermined time interval at least comprises a transmission delay associated with transmission performed between user equipment (UE) and a base station.