Adaptive Fractional Frequency Reuse for Wireless Networks

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Solution Overview

Problem

Existing wireless communication networks face challenges in managing frequency reuse effectively, leading to interference issues at cell edges and suboptimal throughput, as fixed fractional frequency reuse schemes do not adapt to changing coverage conditions within cells.

Innovation Solution

A method and system for adaptive fractional frequency reuse, where base stations dynamically adjust power levels and frequency reuse modes based on detected coverage problems, using multiple power levels and modes to minimize interference and optimize network performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If fixed fractional frequency reuse schemes are used, then frequency reuse pattern is maintained, but adaptability to changing coverage conditions deteriorates

Engineering Contradiction:
Improvefrequency reuse patternVSAvoidadaptability to coverage conditions
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic FFR by allowing base stations to change their frequency reuse mode based on detected coverage conditions. The system transitions from fixed to dynamic operation where the FFR configuration can be adjusted in response to changing network conditions, particularly coverage problems detected through mobile terminal feedback.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the FFR parameter (reuse factor) dynamically based on coverage conditions. When coverage problems are detected, the base station adjusts the FFR configuration to resolve the issue, thereby changing the frequency allocation parameters in response to network conditions.

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If high transmission power is used for cell edge mobile terminals, then coverage is improved, but interference to neighboring cells increases

Engineering Contradiction:
Improvecoverage areaVSAvoidinterference to neighboring cells
Core Design Contradiction:
Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by assigning different transmission power levels to different mobile terminals based on their location. Cell edge terminals receive higher power allocations while cell center terminals use lower power, thereby providing targeted coverage enhancement only where needed and minimizing unnecessary interference.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts transmission power levels based on mobile terminal location and coverage conditions. The base station can change power allocations in response to detected coverage problems, ensuring that high power is used only when and where coverage gaps exist.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If fixed FFR schemes are used, then implementation complexity is reduced, but network throughput deteriorates under changing conditions

Engineering Contradiction:
Improveimplementation complexityVSAvoidnetwork throughput
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements feedback mechanisms where mobile terminals report coverage conditions to their serving base stations. This feedback enables the system to detect coverage problems and trigger appropriate FFR mode changes, thereby maintaining high throughput through adaptive response to network conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system introduces dynamic adaptation to FFR configuration while maintaining relatively simple implementation through predefined FFR modes. The base station can switch between different FFR configurations based on feedback, achieving high throughput without requiring complex real-time optimization algorithms.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP1999982B1Method&system for fractional frequency reuse in a wireless communication network
Publication Date: 2018.08.29 BLACKBERRY LTD
  • EP1999982B1 patent drawingFigure 1
  • EP1999982B1 patent drawingFigure 2~3
  • EP1999982B1 patent drawingFigure 4

AI summary

A method and system for fractional frequency reuse in a communication network. A plurality of fractional frequency reuse modes for wireless communication are defined in which each of the modes are associated with a corresponding group of wireless communication tones assigned to one of a plurality of power levels. Communication with at least one mobile terminal in a first region is established using a fractional frequency reuse mode from the plurality of fractional frequency reuse modes. A coverage problem with communication with at least one of the mobile terminal in the first sector is detected. A base station associated with a second region is notified to change communication within the second region to a different fractional frequency reuse mode from the plurality of fractional frequency reuse modes.