Access Point Interference Detection via Remote Signal Measurement

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Solution Overview

Problem

Wireless networks operating in unlicensed bands face interference issues due to devices outside the range of access points, which existing dynamic channel allocation methods cannot effectively diagnose or mitigate, leading to performance degradations and user-perceived malfunctions.

Innovation Solution

A first access point detects interference affecting a second access point by measuring signal strength during periods of no data traffic and sends an information item indicating the interference, allowing the second access point to identify and address the issue even if the interfering device is out of its range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an access point performs dynamic channel allocation by scanning frequency bands, then it can identify channels with low activity levels, but it cannot detect interferences occurring at remote places outside its range

Engineering Contradiction:
Improveinterference detection capabilityVSAvoiddiagnosis capability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces a remote sensing device as an intermediary between the access point and the remote interfering device. This device is positioned at the remote location to directly detect interferences that are outside the access point's range. The remote sensing device measures signal strength and provides interference information back to the access point, enabling the access point to diagnose and mitigate interferences it cannot directly detect.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If an access point monitors signal strength continuously, then it can detect interferences, but it increases energy consumption and processing overhead

Engineering Contradiction:
Improveinterference detection accuracyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic interference detection instead of continuous monitoring. The access point performs interference detection at scheduled intervals by scanning frequency bands and measuring signal strength at specific time points. This periodic approach maintains reliable interference detection capability while significantly reducing energy consumption and processing overhead compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If an access point scans all frequency bands to detect interferences, then it can identify interfering devices, but it increases detection time and reduces network responsiveness

Engineering Contradiction:
Improveinterference identification accuracyVSAvoiddetection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent divides the frequency band into multiple smaller sub-bands and scans them separately and sequentially. Instead of scanning the entire frequency band at once, the access point segments the scanning process into manageable portions, allowing faster detection of interfering devices while maintaining comprehensive coverage. This segmented approach reduces overall detection time while preserving interference identification accuracy.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method enables effective detection and mitigation of remote interferences, improving network performance by allowing access points to switch channels or adjust configurations based on information about interfering devices not within their direct range.

Implementation Method 1

by measuring a level of strength of a signal received in the frequency channel at a period of time where no data traffic of the second access point is detected

Methodology Applied
Scientific EffectSignal strength measurement:

Data Source

PatentEP3361769B1Method, device and system for detecting interferences
Publication Date: 2020.10.28 INTERDIGITAL CE PATENT HOLDINGS SAS
  • EP3361769B1 patent drawingFigure 1
  • EP3361769B1 patent drawingFigure 2a
  • EP3361769B1 patent drawingFigure 2b

AI summary

A method for detecting interferences in wireless networks is disclosed. A salient idea is to use a first access point for detecting an interference disturbing a wireless device associated with a second access point, wherein the device at the origin of the interference is in the range of the first access point, but not in the range of the second access point. Leveraging on the difference of coverage between different wireless networking technologies, the first access point is capable of detecting both a data traffic of a second access point and a short range interfering device in a same frequency channel. More precisely, by measuring a level of strength of a signal received in the frequency channel at a period of time where no data traffic of the second access point is detected, the first access point is capable of detecting an interference according to the measured signal. The detected interference corresponds to another device using the frequency channel of the second access point, without communicating with the second access point. As the interference detected by the first access point may not be detectable by the second access point (because not being in the range of the second access point although disturbing some of its associated devices), the first access point advantageously sends an information item indicating the interference has been detected. Sending such indication is advantageous as it allows the second access point to detect an interfering device, even if not being in its range.