Neighbor Cell Redirection Under 5G NR Cell Sleep Modes

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Solution Overview

Problem

The implementation of cell DRX/DTX cycles in 5G New Radio (NR) networks is not well defined, leading to inefficiencies in power consumption and potential performance issues for user equipment (UEs) due to undefined signaling and UE/gNB behavior during sleep modes.

Innovation Solution

Configuring a cell ON-OFF pattern with varying sleep modes for gNBs and UEs, allowing for dynamic switching based on UE requirements and group common signaling to redirect UEs to neighbor cells when performance is impacted, optimizing power consumption and traffic handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If cell DRX/DTX cycle is implemented to conserve power, then energy consumption is reduced, but performance of UE is impacted during OFF duration

Engineering Contradiction:

Improvepower consumptionVSAvoidUE performance

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic switching between different cell sleep modes (first sleep mode with longer OFF duration, second sleep mode with shorter OFF duration) based on UE performance requirements. The gNB can transition between sleep modes using group common signaling, allowing the system to adapt between power conservation and performance maintenance without costly RRC signaling

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the OFF duration parameter of the cell DRX/DTX cycle by switching between different sleep modes. The first sleep mode uses a longer OFF duration for maximum power savings, while the second sleep mode uses a shorter OFF duration to maintain UE performance, allowing flexible parameter adjustment based on network conditions

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If cell sleep mode with longer OFF duration is used, then power conservation is improved, but signaling definition is incomplete and UE behavior is undefined

Engineering Contradiction:

Improvepower savingsVSAvoidsignaling completeness

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent preliminarily defines complete UE behavior and gNB signaling for cell DRX/DTX operation before implementation. It specifies exactly what UEs should do during OFF duration (skip monitoring PDCCH, skip receiving PDSCH, skip transmitting PUSCH) and defines group common signaling mechanisms for sleep mode switching, eliminating the incompleteness issue

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the cell sleep operation into distinct first and second sleep modes with different OFF durations, each with clearly defined UE behavior and gNB signaling requirements. This segmentation allows the system to choose appropriate granularity for power savings while maintaining complete signaling definitions

Inventive Principle:

Principle #1Segmentation

3Productivity

If group common signaling is used to switch sleep modes, then signaling overhead is reduced, but UE reselection to neighbor cell may be needed

Engineering Contradiction:

Improvesignaling efficiencyVSAvoidservice continuity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements periodic cell DRX/DTX cycles with defined ON and OFF durations, allowing the system to periodically switch between active and sleep states. Group common signaling is used to indicate sleep mode changes at appropriate periodic intervals, maintaining signaling efficiency while ensuring service continuity through predefined UE behaviors

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS20260040213A1UE Assistance Information for Redirection to Neighbor Cell

Publication Date: 2026.02.05 APPLE INC

AI summary

A user equipment (UE) configured to decode, from signaling received from a base station, a configuration for a cell ON-OFF pattern for a serving cell and at least one cell sleep mode for an OFF duration of the ON-OFF pattern, decode, from signaling received from the base station, a message indicating the UE to reselect to a neighbor cell when the serving cell determines a performance of the UE is impacted by a currently configured cell sleep mode for the OFF duration or in response to a UE request and reselect to the neighbor cell.