Femtocell Coverage Gap Bridging via Dynamic Power Adjustment

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Solution Overview

Problem

Femtocell networks, initially designed for residential and small business use, face challenges in providing consistent and predictable coverage due to unplanned deployment and limited power, leading to patchy connections and inability to serve as a primary network, especially for mobile users.

Innovation Solution

A method that identifies and bridges coverage gaps by increasing the transmission power of access points along user equipment routes, forming coverage corridors to maintain continuous connectivity, using a UE-centric approach that anticipates or responds to user trajectories, and can be pre-provisioned or dynamically adjusted.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If femtocell networks are deployed in residential and small business use, then local coverage is provided, but coverage consistency and reliability deteriorate due to unplanned deployment and limited power

Engineering Contradiction:
Improvecoverage areaVSAvoidcoverage consistency
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The system performs preliminary identification of coverage gaps along user equipment routes before users experience connection failures. By proactively detecting gaps and increasing access point transmission power in advance, the system ensures continuous connectivity without interruption, resolving the reliability issue while maintaining the intended coverage area

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors signal strength and coverage conditions along user routes, using this feedback to dynamically adjust access point transmission power. This closed-loop control ensures that coverage gaps are detected and corrected in real-time, maintaining consistent and reliable coverage across the femtocell network

Inventive Principle:
Principle #23Feedback

2Reliability

If transmission power of access points is increased to bridge coverage gaps, then connectivity reliability improves, but energy consumption increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidtransmission power
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of uniformly increasing transmission power across all femtocell access points, the system applies power increases only to specific access points identified as having coverage gaps along user routes. This localized adjustment maintains connection reliability while minimizing overall energy consumption by affecting only the necessary nodes

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts transmission power based on real-time detection of coverage gaps and user equipment trajectories. Power levels are increased only when and where needed to bridge identified gaps, and can be reduced when gaps are closed or users move away, creating an adaptive energy-efficient solution that maintains reliability

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If femtocell networks operate as secondary supporting resource, then macrocell network maintains primary capacity, but handover frequency and network complexity increase

Engineering Contradiction:
Improvenetwork flexibilityVSAvoidhandover management
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system pre-identifies coverage gaps and establishes coverage corridors along user equipment routes before handovers are needed. By proactively ensuring continuous coverage, the system reduces the frequency of handovers and eliminates ping-pong effects, simplifying handover management while maintaining network flexibility

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system maintains continuous coverage along user routes by bridging gaps between femtocell and macrocell networks, ensuring uninterrupted service. This continuous coverage reduces the need for repeated handovers and connection re-establishment, decreasing network complexity while preserving the ability of the network to adapt to user movements

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP3278594B1Wireless network configuration
Publication Date: 2020.11.18 BRITISH TELECOM PLC
  • EP3278594B1 patent drawingFigure 1
  • EP3278594B1 patent drawingFigure 2~3
  • EP3278594B1 patent drawing

AI summary

In a wireless network formed of short range femtocells, each femtocell provides wireless connectivity to user equipment devices and the user equipment can move around the topographical range covered by the network by handing over to a neighbouring femtocell. Due to the limited range of a femtocell, there will be coverage gaps. If the device moves to a location not covered by a femtocell, it will try to connect to a macrocell of a different wide area cellular network until it is within range of another femtocell network. To minimise handovers from the femtocell network to the macrocell network, each femtocell is arranged to analyse historic log data to detect coverage gaps experienced by the user equipment as it moves along a user equipment route and try to close the gaps by increasing the coverage range of femtocells on either side of the coverage gap to close the gap.