NR Sidelink DRX Resource Allocation for Out-of-Coverage UEs

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently allocating resources for sidelink transmissions by user equipment (UEs) operating in discontinuous reception (DRX) mode, particularly when out-of-coverage, leading to increased power consumption and unreliable data transmission.

Innovation Solution

A UE operating in DRX mode determines resources for sidelink transmission by utilizing assistance information messages (AIMs) from neighboring UEs or a base station, prioritizing resources based on RSRP thresholds and DRX cycles, and optionally performing sensing to ensure reliability and power efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a UE performs Sidelink DISC continuously to monitor PCC and PSSCH, then the reliability of resource allocation is improved, but the power consumption increases

Engineering Contradiction:
Improveresource allocation reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements discontinuous reception (DISC) where the UE periodically wakes up to monitor control information instead of continuous monitoring. The UE monitors PCC and PSSCH at specific intervals (e.g., every 10th subframe) rather than continuously, reducing power consumption while maintaining sufficient reliability for resource allocation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent uses pre-configured DISC patterns and predetermined monitoring schedules where the UE is configured in advance with when to monitor control information. This preliminary arrangement allows the UE to optimize its monitoring behavior without real-time decisions, balancing reliability requirements with power savings.

Inventive Principle:
Principle #10Preliminary action

2Use of energy by moving object

If a UE performs Sidelink DISC with long DRX cycle, then the power saving is improved, but the response time for resource allocation deteriorates

Engineering Contradiction:
Improvepower savingVSAvoidresponse time
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent implements dynamic adjustment of DISC patterns based on channel conditions and traffic requirements. The UE can switch between different DISC patterns (e.g., pattern A with longer cycle for power saving, pattern B with shorter cycle for faster response) depending on current network conditions, optimizing the balance between power saving and response time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies different monitoring strategies to different time periods or conditions. During normal conditions, the UE uses longer DRX cycles for power saving, but during critical periods (e.g., when resource allocation is needed urgently), the UE activates shorter monitoring intervals, creating locally optimized behavior rather than uniform continuous monitoring.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If the network configures frequent DISC pattern changes, then the adaptability to channel conditions is improved, but the signaling overhead increases

Engineering Contradiction:
Improvechannel condition adaptabilityVSAvoidsignaling overhead
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements partial monitoring where the UE monitors control information at strategically selected intervals rather than continuously. The DISC pattern is designed to provide sufficient monitoring for reliable resource allocation without requiring constant updates, reducing signaling overhead while maintaining adequate adaptability to channel conditions.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4122264B1NR sidelink discontinuous reception resource allocation
Publication Date: 2026.05.06 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP4122264B1 patent drawingFigure 1(a)~1(b)
  • EP4122264B1 patent drawingFigure 2~3
  • EP4122264B1 patent drawingFigure 4~5

AI summary

A user device, UE, for a wireless communication system is described. The wireless communication system includes a plurality of user devices, UEs. The UE is to communicate with one or more further UEs using a sidelink, SL. The UE is to operate in a Discontinuous Reception, DRX, mode. When being out-of-coverage, the UE is to obtain one or more resources available for a transmission • from an assistance information message, AIM, received from one or more of the further UEs during an ON duration of one or more DRX cycles, and/or • from an assistance information message, AIM, received from one or more of the further UEs during a listening duration, and/or • by carrying out sensing in a set of sidelink resources or in a sidelink resource pool of the wireless communication system during an ON duration of one or more DRX cycles, and/or • by carrying out sensing in a set of sidelink resources or in a sidelink resource pool of the wireless communication system during a listening duration.