Cell Individual Offset Bias for Heterogeneous Network Range Expansion

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Solution Overview

Problem

Existing cell range expansion techniques in heterogeneous wireless communication networks do not account for differences in user equipment properties and changing traffic loads, leading to inappropriate handovers and interference issues.

Innovation Solution

A decentralized method where user equipment determines its maximum cell individual offset bias based on its current configuration and radio conditions, allowing for dynamic adjustment of cell bias without network visibility, enabling appropriate cell selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If cell range expansion is used to bias user equipment towards low power nodes, then coverage area of low power nodes is expanded, but user equipment suffers from high interference from macro cell

Engineering Contradiction:
Improvecoverage areaVSAvoidinterference
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies different cell individual offset values to different user equipment based on their specific characteristics and radio conditions. Instead of using a uniform bias for all user equipment in the expanded coverage area, the system tailors the offset locally to each user equipment's interference tolerance and signal quality, thereby expanding coverage while managing interference on a per-user basis.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the cell individual offset bias for user equipment based on changing radio conditions, traffic load, and user equipment characteristics. The bias is not static but adapts in real-time to optimize the balance between coverage expansion and interference management, allowing the system to respond to varying conditions in the heterogeneous network.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If a fixed cell bias is applied to all user equipment, then implementation is simple, but it does not account for differences in user equipment properties and traffic load

Engineering Contradiction:
Improveimplementation complexityVSAvoidadaptability to UE characteristics
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

User equipment autonomously determines its own cell individual offset bias based on its measured radio conditions, characteristics, and the configured parameters from the network. Each user equipment self-adjusts its bias without requiring complex network control for each individual case, thereby achieving adaptability while keeping network-side implementation relatively simple.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the cell individual offset parameter dynamically based on user equipment characteristics and radio conditions. By adjusting this key parameter, the system achieves adaptability to different user equipment properties and traffic scenarios without fundamentally changing the cell selection mechanism or requiring complex additional infrastructure.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If user equipment switches to low power node early in high interference conditions, then capacity is increased, but handover performance deteriorates for some user equipment

Engineering Contradiction:
Improvesystem capacityVSAvoidhandover performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies different cell individual offset biases to different user equipment based on their specific interference tolerance and characteristics. User equipment with better interference handling capabilities receives larger biases that encourage early handover to low power nodes, while user equipment more sensitive to interference receives smaller biases, maintaining handover reliability. This local differentiation allows the system to increase overall capacity without uniformly degrading handover performance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cell individual offset acts as an intermediary parameter that mediates between the conflicting goals of increasing system capacity through early handovers and maintaining reliable handovers. By adjusting this intermediate bias parameter based on user equipment characteristics, the system finds an optimal balance that enables capacity improvement while preserving handover success rates.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2941047B1Using a cell individual offset to bias user equipment towards a cell and provide cell range expansion
Publication Date: 2020.07.15 ALCATEL LUCENT SA
  • EP2941047B1 patent drawingFigure 1
  • EP2941047B1 patent drawingFigure 2~3
  • EP2941047B1 patent drawingFigure 4

AI summary

A wireless communication network node cell selection bias method and user equipment cell selection bias method along with a computer program, a network node and user equipment are disclosed. The network node cell selection bias method comprises: communicating to user equipment a control signal operable to control said user equipment to determine a maximum cell individual offset bias for use when applying a cell bias for selecting a neighbouring cell.