UL-WUS Configuration Validity in NES Cell Reselection

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Solution Overview

Problem

In wireless communication systems, user equipment (UE) may miss system information change indications from non-network energy saving (NES) cells while camping in source NES cells, leading to obsolete uplink wake-up signal (UL-WUS) configurations during cell reselection, resulting in high PRACH retransmission failures and undefined UE behavior.

Innovation Solution

Implementing mechanisms for efficient cell selection/reselection with NES cells, including transmitting UL-WUS configurations, defining additional rules for cell selection/reselection procedures, and managing associated non-NES cells to ensure valid UL-WUS configurations before transmitting PRACH requests.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If UE camps in source NES cells, then energy saving is achieved, but system information change indications are missed leading to obsolete UL-WUS configurations

Engineering Contradiction:

Improveenergy savingVSAvoidsystem information update reliability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent applies preliminary action by having the UE acquire and store system information change indications from non-NES cells before actually needing to access them. When cell reselection occurs, the pre-acquired indications are already available to ensure proper UL-WUS configuration, preventing the missed indication problem while maintaining energy saving during camping in source NES cells.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If UL-WUS configuration is used for cell reselection, then cell selection efficiency is improved, but PRACH retransmission failures increase due to obsolete configurations

Engineering Contradiction:

Improvecell selection efficiencyVSAvoidPRACH transmission reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements feedback mechanisms where the UE continuously monitors and updates system information change indications from non-NES cells. This feedback loop ensures that when cell reselection occurs, the UE has the most current UL-WUS configuration information, preventing the use of obsolete configurations and reducing PRACH retransmission failures while maintaining efficient cell selection.

Inventive Principle:

Principle #23Feedback

3Speed

If UE transmits PRACH requests based on stored UL-WUS configuration, then access speed is improved, but retransmission failures increase due to configuration obsolescence

Engineering Contradiction:

Improveaccess speedVSAvoidPRACH request success rate

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-acquiring and storing system information change indications from non-NES cells before cell reselection. This ensures that when the UE needs to transmit PRACH requests, it already has valid UL-WUS configuration information, maintaining fast access speed while preventing retransmission failures caused by obsolete configurations.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20260046775A1Supporting UL-WUS configuration

Publication Date: 2026.02.12 QUALCOMM INC

AI summary

Apparatus, methods, and computer program products for wireless communication are provided. An example method may include receiving, from a network energy saving (NES) cell, an uplink wake-up signal (UL-WUS) configuration for a set of NES cells. The example method may include acquiring MIB/SIB of a non-NES cell for validity check of UL-WUS configuration for a NES cell and receiving an updated UL-WUS configuration. In example aspects, a UE may follow priority rules for cell reselection based on NES type of source and/or target cells.