Sidelink DRX Configuration for Power Saving in Wireless Systems
Solution Overview
Problem
Current NR sidelink technologies face challenges in power saving for UEs with battery constraints, particularly for vulnerable road users and public safety applications, and struggle with achieving high reliability and low latency in busy communication conditions.
Innovation Solution
The proposed solution involves configuring sidelink Discontinuous Reception (DRX) to optimize power consumption and enhance reliability and latency by aligning sidelink DRX wake-up times with Uu DRX wake-up times, using mechanisms such as Sidelink UE Information messages and RRCReconfiguration messages to manage sidelink DRX configurations and resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If sidelink DRX is configured to save power for battery-constrained UEs, then power consumption is reduced, but monitoring reliability may deteriorate
Solution Approach 1:
The patent implements Discontinuous Reception (DRX) with periodic wake-up intervals for monitoring sidelink control channels. The UE alternates between sleep mode and active monitoring periods, waking up at configured intervals to check for sidelink control information. This periodic action reduces power consumption by avoiding continuous monitoring while maintaining the ability to detect important control signals.
Solution Approach 2:
The patent introduces dynamic adjustment mechanisms for DRX parameters including wake-up timing offsets and monitoring durations. The network can configure different DRX cycles and offset values to adapt to varying traffic conditions and reliability requirements. This dynamic configuration allows the system to balance power saving and monitoring reliability based on current operational needs.
2Use of energy by moving object
If sidelink DRX wake-up times are aligned with Uu DRX wake-up times, then power efficiency is improved, but configuration complexity increases
Solution Approach 1:
The patent merges sidelink DRX and Uu DRX operations by aligning their wake-up times. The network configures sidelink DRX parameters including offset values that synchronize sidelink monitoring wake-ups with Uu interface wake-ups. This merging allows the UE to perform both sidelink and Uu monitoring during the same active periods, eliminating the need for separate power management mechanisms and improving overall power efficiency.
Solution Approach 2:
The network acts as an intermediary to coordinate and align the DRX configurations of sidelink and Uu interfaces. Through RRC signaling, the network provides configuration messages that set the wake-up timing offsets for sidelink DRX to match Uu DRX patterns. This intermediary coordination simplifies the UE's power management by providing centralized control over the alignment of different DRX operations.
3Duration of action of moving object
If sidelink DRX is used to extend battery life, then duration of operation is extended, but latency may increase
Solution Approach 1:
The patent implements dynamic DRX configuration where the network can adjust cycle lengths and wake-up offsets based on traffic conditions and latency requirements. For time-sensitive applications, the network can configure shorter DRX cycles or adjust offsets to ensure wake-up times coincide with expected sidelink control information arrivals, thereby reducing latency while still providing power saving benefits.
Data Source
AI summary
A method and device are disclosed from the perspective of a second User Equipment (UE) to configure Sidelink (SL) Discontinuous Reception (DRX). In one embodiment, the method includes the second UE initiating or initializing a sidelink service with a first UE. The method also includes the second UE determining a SL DRX configuration based on association between sidelink service and SL DRX configuration, wherein the SL DRX configuration is associated with the sidelink service. The method further includes the second UE monitoring sidelink control channel based on the SL DRX configuration.