DRX Cycle Configuration for Heterogeneous Network Paging Reliability

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Solution Overview

Problem

In heterogeneous networks (HetNets), user equipment (UE) faces challenges in reliably detecting paging occasions due to interference from aggressor cells, which can lead to increased battery consumption and failure to meet ETWS/CMAS monitoring requirements when limited to reading paging only during on-duration periods that fit into restricted subframes.

Innovation Solution

Configuring the Discontinuous Reception (DRX) cycle to 5*2^n subframes and setting the DRX start offset to align on-duration periods with paging occasions protected by restricted subframes, allowing UE to read paging during active time and reducing unnecessary wake-ups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If UE is limited to reading paging only during on-duration periods that fit into restricted subframes, then interference from aggressor cells is reduced, but ETWS/CMAS monitoring requirements cannot be met and battery consumption increases

Engineering Contradiction:
Improveinterference from aggressor cellsVSAvoidETWS/CMAS monitoring reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent dynamically configures the DRX cycle length to be a multiple of the restricted subframe pattern period, allowing the on-duration to be flexibly positioned within the restricted subframe pattern. This dynamic configuration enables the system to adapt to different traffic conditions and interference patterns while ensuring that paging occasions are properly aligned with protected subframes, thereby meeting both interference reduction and monitoring reliability requirements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the DRX cycle parameter to be a multiple of the restricted subframe pattern period (e.g., 10, 20, 40, 80, 160, 320 subframes). This parameter change ensures that the on-duration periodically aligns with restricted subframes, allowing the UE to read paging during protected periods while maintaining reliable ETWS/CMAS monitoring without excessive battery consumption

Inventive Principle:
Principle #35Parameter changes

2Reliability

If UE reads paging frequently to meet monitoring requirements, then ETWS/CMAS monitoring reliability is improved, but battery consumption increases

Engineering Contradiction:
ImproveETWS/CMAS monitoring reliabilityVSAvoidbattery consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by configuring the DRX cycle to be a multiple of the restricted subframe pattern period, creating a periodic alignment between on-duration and protected subframes. This periodic structure allows the UE to read paging at optimal intervals that meet monitoring requirements while minimizing wake-ups, thereby reducing battery consumption compared to continuous or frequent paging checks

Inventive Principle:
Principle #19Periodic action

3Reliability

If DRX cycle is configured to align with restricted subframes, then paging detection reliability is improved, but device complexity increases

Engineering Contradiction:
Improvepaging detection reliabilityVSAvoidDRX configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent simplifies the configuration by defining the DRX cycle as a multiple of the restricted subframe pattern period using a standardized set of values (10, 20, 40, 80, 160, 320 subframes). This parameter relationship provides a clear, rule-based configuration method that reduces complexity compared to arbitrary DRX cycle settings, while ensuring proper alignment between on-duration and protected subframes for reliable paging detection

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2777339B1Discontinuous reception (DRX) in heterogeneous networks
Publication Date: 2022.06.29 BLACKBERRY LTD
  • EP2777339B1 patent drawingFigure 1~2
  • EP2777339B1 patent drawingFigure 3
  • EP2777339B1 patent drawingFigure 4

AI summary

A method for operating a UE in a wireless communications network is provided. The method comprises attempting, by a UE configured to operate in a DRX mode and with time domain measurement resource restrictions, to read a paging message in a paging occasion in a restricted subframe during DRX active time.