NR-V2X Groupcast DRX Coordination for Power and PRR Balance

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Solution Overview

Problem

Existing power-saving mechanisms in NR-V2X groupcast communication fail to balance power consumption and performance requirements for various communication types, leading to reduced packet reception ratio (PRR) and resource conflicts among groupcast members.

Innovation Solution

Utilize a destination L2 ID as a control parameter to statically or dynamically control DRX cycles and active intervals of UEs, ensuring all group members synchronize their sensing and data transmission based on the L2 ID, reducing resource conflicts and enhancing power-saving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UEs execute sensing operation in every DRX cycle to ensure reliable resource selection, then packet reception ratio (PRR) performance is improved, but power consumption increases

Engineering Contradiction:

Improvepacket reception ratioVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic sensing operations where UEs perform sensing in specific DRX cycles determined by a sequence pattern qK={q1, q2, ..., qK}, rather than continuously. This periodic approach allows UEs to enter sleep mode during non-sensing DRX cycles, significantly reducing power consumption while maintaining reliable resource selection through periodic channel awareness.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent introduces dynamic DRX cycle configurations with different lengths (short DRX and long DRX) and adjustable sensing intervals. The sensing behavior is dynamically controlled by parameters such as the sequence pattern qK, sensing window size, and DRX cycle length, allowing the system to adapt sensing frequency to traffic conditions and reliability requirements.

Inventive Principle:

Principle #15Dynamics

2Use of energy by moving object

If UEs enter idle mode to save power, then power consumption is reduced, but data transmission latency increases

Engineering Contradiction:

Improvepower consumptionVSAvoiddata transmission latency

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent implements dynamic switching between short DRX and long DRX cycles, allowing UEs to transition between different power-saving states based on traffic activity. When traffic is active, short DRX cycles provide faster wake-up times for lower latency. When traffic is inactive, long DRX cycles provide deeper power saving, effectively balancing latency and power consumption.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent performs sensing operations in advance of data transmission in predetermined sensing windows within DRX cycles. This preliminary sensing allows UEs to identify available resources before data arrives, so that when UEs wake up from sleep mode, they can immediately transmit or receive data without additional delay for resource selection.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If UEs perform continuous sensing to reduce random resource selection conflicts, then resource allocation reliability is improved, but device complexity increases

Engineering Contradiction:

Improveresource allocation reliabilityVSAvoidsensing mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the sensing operation into discrete DRX cycles with binary sensing states (sense or sleep) controlled by a sequence pattern. This segmentation simplifies the sensing mechanism by eliminating continuous monitoring requirements and enabling UEs to enter low-power states, reducing device complexity while maintaining resource allocation reliability through periodic sensing.

Inventive Principle:

Principle #1Segmentation

4Adaptability or versatility

If different groupcast members use independent DRX configurations to meet individual performance requirements, then adaptability to different services is improved, but resource conflicts among group members increase

Engineering Contradiction:

Improveservice-specific performance optimizationVSAvoidgroupcast communication reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces asymmetric offset parameters for different groupcast members within the same group. While all members share the same DRX cycle structure and sensing windows, each member is assigned a unique offset value that shifts their specific sensing and reception timing. This asymmetric configuration allows members to maintain individual timing patterns that avoid collisions and resource conflicts while preserving groupcast reliability.

Inventive Principle:

Principle #4Asymmetry

Data Source

PatentUS12376187B2Power saving method with regard to NR-V2X groupcast communication

Publication Date: 2025.07.29 ZHANG BO

AI summary

The present application provides a power saving method with regard to NR-V2X groupcast communication. In the present invention, a destination L2 ID (destination L2 ID) is taken as control parameters, and all group members take the destination L2 ID as reference points, and DRX cycles and active intervals of UEs are statically or dynamically controlled, so that a power saving effect is achieved. Mechanisms in the present invention may guarantee the overall performance in the aspects of power saving, reliability and latency.