Device Signature Correlation for Accurate Indoor Proximity Tracking

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Solution Overview

Problem

Existing device tracking methods, such as label-based and GNSS-based systems, are prone to errors and inaccuracies, especially in indoor environments, and radio-based tracking lacks precision due to signal fading, making it difficult to determine the relative position of devices within containers or vehicles.

Innovation Solution

A method and apparatus that utilize device signatures from sensors like cameras and microphones to generate parameters based on measurements, which are then correlated using neural networks to determine the proximity of mobile devices, allowing for relative positioning within a confined environment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If label-based tracking methods are used, then devices can be assigned to positions, but the method is tedious and prone to error with low automation

Engineering Contradiction:
Improveautomation of device trackingVSAvoidaccuracy of position assignment
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent replaces manual label-based tracking with acoustic signal-based automatic tracking. Devices emit or respond to acoustic signals that are captured by microphones, and neural networks automatically process these signals to determine relative positions, eliminating manual label assignment and improving both automation and reliability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces acoustic signals as an intermediary medium for device tracking. Instead of directly reading labels or using satellite signals, the system uses sound waves that propagate through the environment and carry information about device positions, enabling automatic and reliable tracking

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If GNSS-based tracking is used, then absolute position can be determined outdoors, but signals cannot penetrate walls making indoor tracking unreliable

Engineering Contradiction:
Improvereliability of position determinationVSAvoidapplicability to indoor environments
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the physical parameter used for tracking from electromagnetic satellite signals (GNSS) to acoustic signals. Sound waves can penetrate walls and propagate through indoor environments effectively, making the system adaptable to indoor settings while maintaining reliable position determination

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses bidirectional acoustic communication where devices both emit and receive signals. This feedback mechanism allows devices to determine relative positions by analyzing the acoustic signals they receive from other devices, enabling reliable indoor tracking

Inventive Principle:
Principle #23Feedback

3Measurement precision

If radio-based tracking with triangulation is used, then position can be determined in space, but precision degrades significantly due to signal fading in object-filled spaces

Engineering Contradiction:
Improveposition accuracyVSAvoidsignal fading from objects
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of signal fading into a useful measurement. Instead of trying to avoid multipath propagation and signal degradation, the system uses neural networks to analyze the characteristic patterns of acoustic signals including their reflections and fading, transforming these environmental effects into additional information about the tracking environment that improves rather than degrades precision

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP4042317B1Technique of determining a measure of proximity between two devices
Publication Date: 2026.04.22 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4042317B1 patent drawingFigure 1
  • EP4042317B1 patent drawingFigure 2
  • EP4042317B1 patent drawingFigure 3

AI summary

Disclosed is a technique of determining a measure of proximity between two devices (4, 6). A method implementation of the technique comprises obtaining a first device signature comprising an indication of a first point in time and a first parameter characteristic of a first measurement performed by a first sensor (10) comprised in the first device (4); obtaining a second device signature comprising an indication of a second point in time and a second parameter characteristic of a second measurement performed by a second sensor (12) comprised in the second device (6); and determining, based on the first device signature and the second device signature, the measure of proximity between the first device (4) and the second device (6).