PCI Confusion Detection in Wireless Base Stations

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Solution Overview

Problem

Wireless communication systems face inefficiencies and mobility issues due to uncoordinated communication between neighboring base stations, leading to physical cell identifier (PCI) confusion, which causes handover failures and performance degradation.

Innovation Solution

A method and apparatus for detecting PCI confusion by comparing cell identifiers and Neutral Host Network (NHN) Identifiers between neighboring cells, allowing base stations to change their PCI to avoid confusion, with information exchanged via backhaul links or system information messages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If base stations communicate in an uncoordinated manner in shared spectrum, then device complexity is reduced and ease of operation is improved, but PCI confusion occurs leading to handover failures and system efficiency degradation

Engineering Contradiction:
Improveuncoordinated communicationVSAvoidhandover success rate
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by having base stations proactively detect and report PCI conflicts before they cause handover failures. The conflict detection mechanism identifies PCI confusion in advance, allowing the network to resolve conflicts by reassigning PCIs before mobility operations are affected, thus preventing handover failures while maintaining uncoordinated operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback through a conflict detection and reporting mechanism where base stations monitor for PCI conflicts, report them to the network, and receive resolution instructions. This feedback loop enables the system to maintain uncoordinated base station operation while reliably detecting and resolving PCI confusion to prevent handover failures.

Inventive Principle:
Principle #23Feedback

2Productivity

If base stations use common PCI in shared spectrum, then spectral efficiency is improved and resource utilization is optimized, but PCI confusion arises causing mobility issues and performance degradation

Engineering Contradiction:
Improvespectral efficiencyVSAvoidcell identification accuracy
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent applies segmentation by dividing the cell identification process into multiple components: PCI for spectral efficiency, ECGI for unique identification, and conflict detection mechanisms. This segmentation allows multiple base stations to use common PCIs for resource optimization while maintaining unique ECGIs to prevent identification confusion, thus resolving the contradiction between spectral efficiency and identification accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses ECGI as an intermediary element that resolves the conflict between using common PCIs for spectral efficiency and maintaining unique cell identification. The ECGI serves as a secondary identifier that disambiguates cells with common PCIs, allowing the system to achieve both spectral efficiency through PCI reuse and accurate cell identification through ECGI.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If PCI confusion detection mechanisms are implemented, then handover success rate is improved, but device complexity and measurement overhead increase

Engineering Contradiction:
Improvehandover success rateVSAvoiddetection mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies self-service by enabling base stations to autonomously detect PCI conflicts using their existing measurements and information. The conflict detection mechanism leverages already-available data such as PCI, ECGI, and neighbor cell information that base stations maintain for normal operation, eliminating the need for additional complex detection infrastructure while improving handover success rates.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3469826B1Enhanced neighbor relations and physical cell identifier confusion detection
Publication Date: 2020.06.03 QUALCOMM INC
  • EP3469826B1 patent drawingFigure 1
  • EP3469826B1 patent drawingFigure 2
  • EP3469826B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for enhanced neighbor discovery through enhanced automatic neighbor relations (ANR) and for detecting cell identifier confusion and are described. Neighboring base stations may provide information to one another, including using ANR, that may avoid or help to resolve cell identity confusion. For example, a NHN-ID may be defined to avoid or resolve cell identify confusion. A wireless device, such as a base station or a user equipment (UE), may determine whether neighboring cells are using a common cell identifier and may adjust operations accordingly. For example, a device may detect physical cell identity (PCI) confusion by determining whether two neighboring cells have the same PCI and different Evolved Universal Terrestrial Access Network (E-UTRAN) Cell Global Identifiers (ECGIs) or different Neutral Host Network Identifier (NHN-IDs). A network entity may then inform the neighboring cells having the same PCI of the confusion.