NR V2X Sidelink DRX Configuration for Broadcast-to-Unicast Setup
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Solution Overview
Problem
In sidelink communication, there is a challenge in determining the appropriate DRX configuration for a UE to receive broadcast messages before establishing a unicast connection, which affects power consumption and communication efficiency.
Innovation Solution
A method and apparatus for wireless communication that utilize a default discontinuous reception (DRX) configuration for groupcast or broadcast, including information on sidelink DRX cycle and active time, allowing UEs to receive messages for establishing unicast connections based on this configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a UE continuously monitors broadcast messages before unicast connection establishment, then communication reliability is improved, but power consumption increases
Solution Approach 1:
The patent implements discontinuous reception (DRX) cycles where the UE periodically wakes up to monitor broadcast messages and then enters sleep mode. The UE monitors during active periods defined by DRX configuration parameters (drx-OnDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-Timer) and remains in low-power state during inactive periods, achieving periodic monitoring that balances reliability and power consumption
Solution Approach 2:
The patent applies default DRX configuration parameters before unicast connection establishment to enable the UE to enter DRX mode during the connection setup phase. This preliminary configuration allows the UE to monitor broadcast messages with reduced power consumption even before a dedicated unicast connection is established, by using default values for DRX parameters that are applied in advance
2Use of energy by moving object
If a UE enters DRX mode during unicast connection establishment, then power consumption is reduced, but connection establishment time increases
Solution Approach 1:
The patent dynamically adjusts DRX configuration parameters during unicast connection establishment based on connection setup progress. The UE transitions from continuous monitoring during initial connection setup to DRX mode as connection establishment progresses. The network can dynamically modify DRX parameters (drx-OnDurationTimer, drx-InactivityTimer) based on traffic conditions and connection state, optimizing the balance between power saving and connection establishment speed
Solution Approach 2:
The patent changes DRX parameter values based on connection establishment stage and traffic conditions. Default DRX parameters are applied during connection setup, and these parameters can be adjusted or overridden by dedicated RRC configurations as the connection is established. The system modifies parameters like drx-SlotOffset, drx-HARQ-RTT-Timer, and drx-RetransmissionTimer to optimize both power consumption and connection establishment time
3Productivity
If dedicated DRX configuration is provided after unicast connection establishment, then communication efficiency is improved, but device complexity increases
Solution Approach 1:
The patent segments DRX configuration into default configurations applicable to all UEs and dedicated configurations for specific UEs or services. The default DRX configuration provides baseline power saving for all UEs during connection establishment, while dedicated RRC configurations provide optimized DRX parameters for specific UEs based on their traffic patterns and service requirements. This segmentation allows the system to manage complexity by separating universal from customized configurations
Solution Approach 2:
The patent creates a universal default DRX configuration that serves multiple purposes: it enables power saving during connection establishment, provides a baseline for all UEs regardless of service type, and can be overridden or refined by dedicated configurations. This multi-functional default configuration reduces the need for complex per-UE configuration management while still providing effective power saving across diverse scenarios
Data Source
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AI summary
Presented in one embodiment is a method by which a first device performs wireless communication. The method may comprise the steps of: acquiring an SL DRX configuration including information related to a sidelink discontinuous reception (SL DRX) cycle and information related to an activation time; transmitting, to a second device, first sidelink control information (SCI) for scheduling a first physical sidelink shared channel (PSSCH) through a first physical sidelink control channel (PSCCH); transmitting, to the second device, second SCI and a first medium access control (MAC) protocol data unit (PDU) through the first PSSCH; determining a first physical sidelink feedback channel (PSFCH) resource in a first PSFCH slot on the basis of an index of a slot related to the first PSSCH and an index of a sub channel; and receiving, from the second device, first hybrid automatic repeat request (HARQ) feedback for the first MAC PDU on the basis of the first PSFCH resource. For example, the first PSFCH slot can be included in an inactivation time at the time point at which the first MAC PDU is transmitted. For example, the first PSFCH slot can be included in an activation time at the time point at which the first HARQ feedback is received.