Random Cell Selection for Even Network Loading Distribution

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Solution Overview

Problem

Existing cell selection mechanisms in GSM systems are sub-optimal for data communication services, leading to unequal loading distribution across cells, as they primarily rely on Receive Signal Strength Indication (RSSI) levels, causing one cell to become heavily loaded while others remain idle or lightly loaded.

Innovation Solution

A method and apparatus for autonomous mobile station cell selection that determines available cells by monitoring RSSI and other signal measurements, forming an available station set, and randomly allocates a communication station from this set to distribute loading evenly across the network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cell selection is based on RSSI levels, then signal quality is optimized, but loading distribution becomes unequal

Engineering Contradiction:
Improvesignal qualityVSAvoidloading distribution
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the cell selection parameter from RSSI (signal strength) to a random selection mechanism among available cells. This parameter change resolves the contradiction by decoupling cell selection from signal strength optimization, allowing equal loading distribution while maintaining acceptable signal quality through the availability criterion.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of selecting the cell with the strongest signal (conventional approach), the patent inverts the logic by randomly selecting from all available cells regardless of signal strength hierarchy. This inversion equalizes the selection probability across cells, achieving balanced loading distribution.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If mobile stations select the strongest signal cell, then connection reliability is improved, but network loading becomes concentrated

Engineering Contradiction:
Improveconnection reliabilityVSAvoidnetwork loading
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the selection criterion from signal strength maximization to random selection among available cells. This parameter change distributes the quantity of network loading evenly across multiple cells while maintaining connection reliability through the availability threshold criterion.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Each mobile station independently performs random selection from available cells based on its own measurements of cell availability. This self-service mechanism naturally distributes loading across the network without requiring centralized control or coordination.

Inventive Principle:
Principle #25Self-service

3Device complexity

If autonomous cell selection is implemented, then system complexity is reduced, but loading distribution control is lost

Engineering Contradiction:
Improvesystem complexityVSAvoidloading distribution
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements autonomous cell selection where each mobile station independently selects a cell based on random choice from available cells. This self-service approach reduces system complexity by eliminating centralized control while achieving loading distribution through the inherent randomness of individual selections.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of implementing complex centralized control to manage loading distribution, the patent inverts the approach by giving autonomy to individual stations with simple random selection logic. This inversion achieves loading distribution control without centralized complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP1887821B1Apparatus, and associated method, for performing cell selection in a packet radio communication system
Publication Date: 2012.12.26 BLACKBERRY LTD
  • EP1887821B1 patent drawingFigure 1
  • EP1887821B1 patent drawingFigure 2
  • EP1887821B1 patent drawingFigure 3

AI summary

Cell selection apparatus, and an associated methodology, for a radio communication system. Cell selection is made in a manner to distribute loading amongst cells of a radio communication system. Determinations are made of available cells, that is, cells whose base transceiver stations broadcast signals of characteristics at least as good as a selected threshold. Selection of a cell is made from amongst the available cells. The selection is made in a random manner to facilitate thereby distribution of communication loading.