NR-U Paging with Multiple Paging Occasions Under LBT Constraints

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Solution Overview

Problem

The paging procedure in NR-U is impacted by LBT, leading to potential delays in paging UEs, especially for low latency services and Public Warning System indications, and the benefits of the RRC_INACTIVE state are compromised due to unreliable channel access.

Innovation Solution

Enhancements to the NR-U paging procedure include monitoring multiple POs during a DRX cycle, using a paging window, defining POs with multiple sweeps/repetitions, signaling DL channel access indication, and adapting DRX dynamically to ensure reliable paging without excessive latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LBT is used for channel access in NR-U, then channel access reliability is improved, but paging latency increases

Engineering Contradiction:

Improvechannel access reliabilityVSAvoidpaging latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The network performs LBT and channel access attempts in advance before the scheduled PO, and notifies the UE of the channel access status. This allows the UE to prepare accordingly and avoid waiting through the entire DRX cycle, thereby reducing paging latency while maintaining reliable channel access through LBT

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The network provides feedback to the UE about the LBT success or failure status. This feedback mechanism allows the UE to adjust its monitoring behavior based on actual channel conditions, reducing unnecessary waiting time while ensuring reliable page delivery when the channel is accessible

Inventive Principle:

Principle #23Feedback

2Reliability

If UEs monitor multiple POs during DRX cycle, then paging reliability is improved, but power consumption increases

Engineering Contradiction:

Improvepaging reliabilityVSAvoidUE power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The network performs preliminary LBT and channel access attempts before the scheduled PO and notifies the UE of the results. When LBT succeeds, the UE knows to monitor the PO; when LBT fails, the UE can skip monitoring, thereby maintaining paging reliability while significantly reducing power consumption by avoiding unnecessary monitoring of multiple POs

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The network provides feedback about channel access status to guide UE monitoring behavior. This feedback allows the UE to adapt its monitoring strategy dynamically - monitoring only when necessary - thus resolving the contradiction between ensuring reliable page reception and minimizing power consumption

Inventive Principle:

Principle #23Feedback

3Use of energy by moving object

If DRX cycle is extended for power saving, then power consumption decreases, but paging latency increases

Engineering Contradiction:

Improvepower consumptionVSAvoidpaging latency

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The network performs preliminary channel access attempts and notifies the UE before the scheduled PO. This allows the system to use extended DRX cycles for power saving while reducing actual paging latency, because the UE is alerted in advance when a page is coming, eliminating the need for the UE to stay awake and monitor continuously

Inventive Principle:

Principle #10Preliminary action

4Reliability

If LBT failures occur frequently, then channel access becomes unreliable, but increasing monitoring attempts increases power consumption

Engineering Contradiction:

Improvechannel access reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The network performs preliminary LBT attempts and communicates the results to the UE before the scheduled PO. This allows the system to handle frequent LBT failures efficiently - the UE only monitors when the network successfully accesses the channel, avoiding wasteful monitoring attempts while maintaining reliable channel access

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The network provides feedback about LBT success/failure to guide UE monitoring decisions. This feedback mechanism resolves the contradiction by allowing the system to maintain high channel access reliability through multiple LBT attempts while minimizing power consumption - the UE monitors only when necessary, based on network feedback rather than continuously or at every PO

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12568465B2Paging for unlicensed new radio

Publication Date: 2026.03.03 INTERDIGITAL PATENT HOLDINGS INC

AI summary

Methods and apparatus are disclosed pertaining to paging for Unlicensed New Radio (NR-U). Methods include means to: perform paging using multiple paging occasions (POs) during a DRX Cycle, perform paging using a paging window, perform paging using a PO comprised of multiple sweeps and/or repetitions, signal DL channel access indication for paging, and perform paging using dynamic DRX. In accordance with one embodiment, an apparatus may receive a signal comprising a plurality of POs, wherein each PO comprises a plurality of physical downlink control channel (PDCCH) monitoring occasions. The apparatus may monitor, based on receiving an identifier associated with the apparatus, a portion of the plurality of paging occasions. The apparatus may detect, in a PDCCH monitoring occasion of the plurality of PDCCH monitoring occasions in the monitored portion, paging downlink control information (DCI).