Cell Selection Using Extended Restriction Information

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Solution Overview

Problem

In heterogeneous wireless communication networks, the existing cell selection methods may fail to select an optimal cell, especially during hand-over, cell re-selection after communication termination, or radio link failure, leading to potential communication quality issues.

Innovation Solution

The technology involves a cell selection method that uses extended cell restriction information, applied by the base station to the mobile station, to exclude unsuitable cells from the selection candidates, utilizing carrier aggregation across different frequency bands and incorporating specific cell restriction criteria for efficient cell selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing cell selection methods are used in heterogeneous networks, then the cell selection procedure is simple, but the probability of selecting a suitable cell decreases and communication quality deteriorates

Engineering Contradiction:
Improveprobability of selecting suitable cellVSAvoidcell selection procedure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The base station performs preliminary actions by determining extended cell restriction information before the mobile station performs cell selection. The base station identifies and restricts unsuitable cells in advance based on network conditions, handover status, and cell configuration, then provides this restriction information to the mobile station to guide its cell selection process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Extended cell restriction information acts as an intermediary between the base station's network management functions and the mobile station's cell selection process. This intermediate information structure allows the base station to influence cell selection outcomes without directly controlling the mobile station's autonomous selection process, resolving the contradiction between simplicity and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If extended cell restriction information is applied, then communication quality is improved, but information processing complexity increases

Engineering Contradiction:
Improvecommunication qualityVSAvoidinformation processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The extended cell restriction information applies different restriction levels to different cells based on their specific characteristics. Instead of uniform restriction across all cells, the base station tailors restriction information to individual cells' suitability for the specific mobile station, considering factors like handover status, cell radius, and configuration type.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the parameter of cell restriction from binary (restricted/not restricted) to a multi-level system with extended restriction information. This includes modifying restriction parameters based on handover status, cell configuration type (intra-frequency, inter-frequency, inter-RAT), and other contextual factors, allowing more nuanced control over cell selection.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If handover is performed in heterogeneous networks, then mobility is enabled, but handover failure probability increases

Engineering Contradiction:
Improvemobility capabilityVSAvoidhandover success probability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The base station applies preliminary anti-action by proactively restricting access to unsuitable target cells before the mobile station attempts handover to those cells. The extended cell restriction information preemptively prevents handover attempts to cells that would likely fail, such as cells with incompatible configurations or unsuitable conditions, thereby reducing handover failure probability while maintaining mobility to appropriate cells.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP2869638B1Terminal device, base station device, communication system, cell selection method, and integrated circuit
Publication Date: 2019.02.27 SHARP KK
  • EP2869638B1 patent drawingFigure 1
  • EP2869638B1 patent drawingFigure 2
  • EP2869638B1 patent drawingFigure 3

AI summary

Provided are a terminal apparatus, a base station apparatus, a communication apparatus, a cell selection method, and an integrated circuit in which a cell selection procedure between the mobile station apparatus and the base station apparatus are efficiently performed to improve communication quality. The terminal apparatus determines whether or not a cell detected by the terminal apparatus is suitable for a cell selection candidate on the basis of first cell restriction information indicating cell access restriction that is applied during cell selection, second cell restriction information that is determined by the terminal apparatus whether or not to apply, and a cell measurement result.