Wireless Detector for Unpredictable Interference in Industrial Networks

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Solution Overview

Problem

Industrial wireless networks in license-free bands face challenges from external interference and malicious jamming, which existing frequency-hopping and channel blacklisting mechanisms struggle to effectively mitigate, as these can be adapted by malicious transmitters to impair communication.

Innovation Solution

A wireless network node with a detector and delay component that compares the energy pattern of received signals with expected patterns, emitting an alarm to trigger channel changes and switch actions to prevent interference, and optionally switching to a safe mode to reduce data packet losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequency-hopping schedule is used to mitigate interference, then average resilience to unpredictable interference is improved, but malicious jammers can learn the schedule and adapt jamming signals to impair all communication attempts

Engineering Contradiction:
Improveresilience to unpredictable interferenceVSAvoidadaptability of malicious jammer
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The detector performs preliminary detection of interfering signals by analyzing energy patterns before the receiver processes the main signal. By detecting and flagging interference in advance using a separate detection path with delay component, the system can prepare countermeasures or alert the receiver to expected interference, improving resilience without relying solely on reactive frequency hopping that malicious actors can predict

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A detector is introduced as an intermediary component between the antenna and the receiver. This detector independently monitors signal energy patterns and provides early warning of interference without being part of the main communication path. The detector acts as a mediator that separates the detection function from the reception function, allowing interference detection without compromising the main communication flow or revealing patterns to malicious jammers

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If channel blacklisting is combined with frequency hopping, then protection from external interference is improved, but device complexity increases

Engineering Contradiction:
Improveprotection from external interferenceVSAvoidcomplexity of interference mitigation mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system segments the interference mitigation function into separate components: a detector that monitors energy patterns, a delay component that buffers signals, and the main receiver that processes legitimate communications. This segmentation allows each component to perform its specific function efficiently without the complexity of integrating all interference countermeasures into a single complex system, while still providing comprehensive protection

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detector serves as an intermediary that simplifies the overall system architecture by handling the complex task of interference pattern recognition independently. Rather than requiring the main receiver to perform complex interference analysis and countermeasure selection, the detector filters out interference cases and alerts the receiver, reducing the computational burden and complexity of the main communication path

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If detector compares energy pattern of input signal with expected energy pattern, then detection precision is improved, but processing time increases due to pattern comparison

Engineering Contradiction:
Improveinterference detection precisionVSAvoidsignal processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The detector performs a simplified partial comparison by focusing specifically on energy pattern characteristics rather than analyzing the complete signal structure. This partial action approach allows the system to detect interference with sufficient precision by monitoring only the most relevant feature (energy distribution over time) while avoiding the time-consuming analysis of full signal content, thus reducing processing time while maintaining effective detection

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3925101B1Radio-based detector and method to protect against unpredictable interference in industrial wireless communications
Publication Date: 2024.09.25 HITACHI ENERGY LTD
  • EP3925101B1 patent drawingFigure 1
  • EP3925101B1 patent drawingFigure 2
  • EP3925101B1 patent drawingFigure 3

AI summary

A method, a node and a detector for detecting an interfering signal in a wireless network communication system comprising a network manager and several nodes,each node (202B) comprising a detector (204) for receiving input signals from at least one antenna, a delay component (205) for delaying a received input signal,and a receiver (206RX) for determining an energy pattern of expected received input signals. The detector (204) is configured to send an alarm signal to the receiver (206RX) depending on the presence or absence of an interfering signal from an interferer 203 and an active/inactive state of the receiver (206RX).