Sidelink HARQ DRX Timing With Active BWP Symbols and Slots

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Solution Overview

Problem

Existing wireless communication systems face challenges in optimizing downlink discontinuous reception (DRX) for sidelink transmission, particularly in evolving networks like 5G, which require efficient management of DRX timers and PDCCH monitoring to enhance data throughput and support voice over IP and multimedia services.

Innovation Solution

A method for configuring DRX timers in User Equipment (UE) based on symbol and slot lengths, utilizing SL Hybrid Automatic Repeat Request (HARQ) processes, and monitoring PDCCH during active DRX timers to optimize DRX operations for sidelink communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If DRX timers are configured with fixed values regardless of BWP changes, then device complexity is reduced, but data throughput deteriorates due to misalignment with active BWP parameters

Engineering Contradiction:
Improvedata throughputVSAvoidDRX timer management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic DRX timer configuration where timer values are adjusted based on the active Downlink Bandwidth Part (BWP) parameters. When the UE switches to a different active BWP, the DRX timer values are automatically updated to match the new BWP's symbol and slot lengths, ensuring optimal data throughput without requiring complex manual reconfiguration

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of DRX timers based on the active BWP configuration. Specifically, when the active BWP changes, the DRX timer values are recalculated and updated to reflect the new symbol and slot lengths of the active BWP, allowing the system to adapt to different bandwidth configurations and maintain high data throughput

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the UE monitors PDCCH continuously without DRX, then reliability of downlink control reception is improved, but energy consumption increases

Engineering Contradiction:
ImprovePDCCH reception reliabilityVSAvoidUE energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic PDCCH monitoring through DRX (Discontinuous Reception) cycles. Instead of continuously monitoring PDCCH, the UE monitors periodically at intervals defined by DRX timer values, which are dynamically adjusted based on active BWP parameters. This periodic monitoring maintains reliable downlink control reception while significantly reducing energy consumption compared to continuous monitoring

Inventive Principle:
Principle #19Periodic action

3Adaptability or versatility

If DRX timer values are updated on every BWP switch, then adaptability to different BWP configurations is improved, but device complexity increases due to frequent timer reconfiguration

Engineering Contradiction:
ImproveBWP configuration adaptabilityVSAvoidtimer reconfiguration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a self-service mechanism where the UE automatically updates its own DRX timer values when the active BWP changes. The UE monitors BWP switching events and autonomously recalculates and applies new DRX timer values based on the active BWP's symbol and slot lengths, eliminating the need for complex network-controlled reconfiguration procedures and reducing signaling overhead

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4391430B1Method and apparatus for downlink discontinuous reception regarding sidelink transmission in a wireless communication system
Publication Date: 2025.08.06 ASUS TECH LICENSING INC
  • EP4391430B1 patent drawingFigure 1
  • EP4391430B1 patent drawingFigure 2
  • EP4391430B1 patent drawingFigure 3

AI summary

A method a User Equipment, UE, can comprise receiving a configuration of a first Discontinuous Reception, DRX, timer with a value in number of symbols (1022), receiving a configuration of a second DRX timer with a value in number of slot lengths (1024), transmitting, via a Sidelink, SL, Hybrid Automatic Repeat Request, HARQ, process, a first SL transmission associated with SL configured grant Type 1 (1026), starting the first DRX timer for the SL HARQ process in response to the first SL transmission, wherein the UE determines a first symbol length associated with the first DRX timer based on a symbol length of an active Downlink, DL, Bandwidth Part, BWP, of a Primary Cell, PCell, (1028), starting the second DRX timer for the SL HARQ process in response to expiration of the first DRX timer which was started in response to the first SL transmission, wherein the UE determines a first slot length associated with the second DRX timer based on a slot length of the active DL BWP of the PCell (1030), and monitoring Physical Downlink Control Channel, PDCCH, when the second DRX timer is running (1032).