Semipersistent Scheduling Offset for Jitter-Aware Downlink Traffic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing 5G NR systems face challenges in efficiently managing downlink traffic with varying jitter and latency requirements, particularly for high-capacity services like virtual reality applications, leading to inefficient power consumption and performance degradation due to unnecessary monitoring and decoding of unscheduled data resources.
Innovation Solution
Implementing adaptive semipersistent scheduling (SPS) by dynamically offsetting SPS resource sets based on traffic changes and activating/deactivating scheduled resources to minimize power consumption and latency, using device-specific or group-specific scrambling codes to ensure only relevant data is decoded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If user equipment continuously monitors and decodes all scheduled data resources, then data reception reliability is improved, but power consumption increases
Solution Approach 1:
The patent implements dynamic SPS resource allocation where the network can activate or deactivate SPS resources based on traffic conditions. The UE adapts its monitoring behavior dynamically - continuously monitoring when SPS is activated, and entering sleep mode when deactivated. This dynamic adjustment resolves the contradiction by making the system flexible rather than static, allowing reliability to be maintained when needed while reducing power consumption when traffic is absent.
Solution Approach 2:
The patent employs a mechanism where SPS resources are discarded (deactivated) when not needed and can be recovered (reactivated) when traffic resumes. The network sends activation/deactivation indications to control this process. This allows the system to eliminate unnecessary monitoring of empty resources, significantly reducing power consumption while maintaining the ability to quickly resume reliable reception when data arrives.
2Loss of time
If semipersistent scheduling resources are allocated for periodic traffic, then latency is reduced, but power consumption increases due to continuous monitoring
Solution Approach 1:
The patent makes SPS configuration dynamic by introducing activation and deactivation control. When SPS is activated, UE monitors resources at the configured periodic interval, ensuring low latency for periodic traffic. When deactivated, UE enters sleep mode between activation events, dramatically reducing power consumption. This dynamic control allows the system to achieve low latency only when actually needed rather than continuously.
Solution Approach 2:
The patent applies periodic monitoring only when SPS is activated, rather than continuous monitoring. The UE monitors SPS resources at the configured periodic interval (e.g., every 10ms, 20ms, or 40ms) when activation is indicated, and remains inactive between periods when deactivation is indicated. This periodic action maintains low latency performance while avoiding the power consumption of continuous monitoring.
3Productivity
If multiple user equipment share the same downlink resources, then resource efficiency is improved, but decoding complexity increases
Solution Approach 1:
The patent segments the downlink resources by assigning different SPS configurations (different periodicities, time offsets, and frequency resources) to different UEs. This segmentation allows multiple UEs to share the overall downlink capacity while each UE only needs to monitor its specific configured resources. The network can further segment resources dynamically by activating/deactivating SPS for specific UEs based on their traffic needs, reducing the decoding burden on each device.
Data Source
AI summary
A radio access network node determines a change in condition of traffic directed to a user equipment. The condition change may comprise jitter caused by a core network component or the condition change may comprise lack of traffic to transmit to the user equipment. The node may determine an offset to compensate for the jitter and transmit the offset to the user equipment, to be used by the user equipment to modify previously-scheduled semipersistent scheduling occasions. The node transmits the jitter-altered downlink traffic according to semipersistent scheduling occasions that have been modified by the offset. If no traffic data is present at the node to transmit to the user equipment, the node may transmit an activate/deactivate indication to be used by the user equipment to deactivate monitoring of a previously-scheduled semipersistent scheduling occasion or to activate monitoring of a different occasion resource.