Sidelink DRX Wake-Up Alignment for Power-Efficient Reception

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Solution Overview

Problem

Existing sidelink communication technologies, particularly in Release 16 (R16), do not adequately support power saving for vulnerable road users (VRUs) and UEs in public safety and commercial use cases, necessitating improved power-efficient sidelink Discontinuous Reception (DRX) operations.

Innovation Solution

Configuring DRX information with timers and offsets for sidelink communication, including on-duration, inactivity, HARQ round trip, and retransmission timers, to align wake-up times among UEs and minimize power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If sidelink DRX is implemented to save power consumption, then power saving is improved, but data reception reliability may deteriorate due to discontinuous monitoring

Engineering Contradiction:

Improvepower consumptionVSAvoiddata reception reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies preliminary action by having the receiving UE send a first indication information before entering DRX sleep state, and the transmitting UE prepare and send second indication information in advance. This allows the receiving UE to wake up from DRX state and receive data without interruption, thereby maintaining data reception reliability while still achieving power saving during DRX operation.

Inventive Principle:

Principle #10Preliminary action

2Use of energy by moving object

If DRX cycle time is extended to reduce power consumption, then power saving is improved, but wake-up time alignment among UEs becomes more difficult

Engineering Contradiction:

Improvepower savingVSAvoidwake-up time alignment

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The patent applies feedback by having UEs exchange indication information about their DRX state and wake-up timing. The transmitting UE receives feedback from the receiving UE about its DRX configuration and adjusts transmission timing accordingly. This feedback mechanism enables wake-up time alignment even with extended DRX cycles, as UEs coordinate their operations based on real-time state information exchange.

Inventive Principle:

Principle #23Feedback

3Reliability

If DRX on-duration timer is increased to ensure data reception, then data reception reliability is improved, but power consumption increases

Engineering Contradiction:

Improvedata reception reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary action by having the receiving UE send first indication information before the actual data transmission begins. This allows the transmitting UE to prepare the second indication information in advance and schedule transmissions during optimal DRX windows, thereby ensuring data reception reliability without requiring excessively long on-duration timers that would increase power consumption.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12446102B2Method and apparatus for sidelink DRX operation

Publication Date: 2025.10.14 LENOVO (BEIJING) LTD

AI summary

Embodiments of the present application are directed to a method and apparatus for sidelink DRX operation. An exemplary method may include: configuring DRX information for sidelink, wherein the DRX information includes a value of DRX on-duration timer, a DRX cycle, and at least one DRX offset value; and starting the DRX on-duration timer from a beginning position based on the DRX cycle and the DRX offset value.