Multibit Wake-Up Signaling for UE Cell Dormancy Control

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Solution Overview

Problem

Existing wireless communication networks face inefficiencies in Scell activation/deactivation procedures, particularly in 5G technologies, leading to high UE power consumption due to unnecessary PDCCH monitoring, and lack clear guidance on UE behavior with simultaneous WUS and multiple DRX configurations.

Innovation Solution

Implementing a multibit wake-up signal (WUS) with separate indications for primary and secondary cells, allowing the UE to start or not start an on-duration timer and apply dormancy or non-dormancy behavior based on the received multibit indication, complemented by a timer-based mechanism for transitioning between states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE monitors PDCCH continuously for Scell activation/deactivation, then the network can maintain responsive cell management, but the UE power consumption increases

Engineering Contradiction:

Improvenetwork responsivenessVSAvoidUE power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements discontinuous reception (DRX) cycles where the UE alternates between active monitoring periods and sleep periods. During active periods, the UE monitors PDCCH for Scell activation/deactivation commands; during sleep periods, the UE powers down the receiver. This periodic action maintains network responsiveness during active periods while significantly reducing power consumption during sleep periods.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The network sends wake-up signals (WUS) before the UE's active DRX period to prepare the UE for upcoming data transmissions. This preliminary action allows the UE to wake up only when necessary, avoiding continuous monitoring and reducing power consumption while maintaining the ability to respond to network requests.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If the UE handles multiple DRX configurations simultaneously, then the network can manage multiple cell groups efficiently, but the UE behavior becomes complex and ambiguous

Engineering Contradiction:

Improvenetwork flexibilityVSAvoidUE behavior clarity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent segments the handling of multiple DRX configurations by introducing separate indication fields in DCI formats for each DRX configuration. Each indication field independently controls the corresponding DRX configuration, allowing the UE to clearly determine which DRX configuration to activate or deactivate without ambiguity, even when multiple configurations are present.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different indication mechanisms to different DRX configurations based on their specific requirements. Primary cell DRX configurations use one indication method, while secondary cell group DRX configurations use another, allowing each configuration to be optimized and controlled independently, improving both network flexibility and UE operational clarity.

Inventive Principle:

Principle #3Local quality

3Device complexity

If the network uses single-bit WUS indication, then the signaling is simple, but it cannot provide separate control for primary and secondary cells

Engineering Contradiction:

Improvesignaling simplicityVSAvoidcell-specific control capability

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transitions from a single-bit indication to a multi-bit indication structure by adding another dimension to the WUS. The DCI format includes separate indication fields for primary cell DRX configuration and secondary cell group DRX configuration, enabling independent control of each cell type while maintaining a systematic and organized signaling approach.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4032345B1Radio network node, user equipment and methods performed in a wireless communication network

Publication Date: 2025.09.03 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

Embodiments herein relate to a method performed by a user equipment, UE (10), for communicating in a wireless communication network. The UE (10) receives a wake-up signal with a multibit indication from a radio network node (12), wherein the multibit indication comprises a first bit indicating to start or not to start, for a first cell, an on-duration timer at one or more of the next occurrence of an on-duration, and a second bit indicating to apply dormancy or non-dormancy behavior on a second cell at the next occurrence of an on-duration for the second cell. The UE (10) further performs an action related to the wake-up signal taking the received multibit indication into account.