Indoor Cellular Positioning Using Speed-Based Measurement Refinement

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Solution Overview

Problem

Existing methods fail to accurately determine indoor locations of user devices in cellular networks due to incomplete or invalid positioning information, especially in scenarios where satellite and terrestrial georeferencing are unavailable or restricted, leading to inaccurate location determination.

Innovation Solution

A method and system that analyze measurement sequences from user devices to identify indoor locations by determining average speed estimates and refining position estimates using Enhanced Cell ID positioning techniques, smoothing techniques like Kalman filtering, and utilizing indoor expected powers based on electromagnetic propagation models.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If satellite georeferencing functionalities (GPS/GNSS) are used for positioning, then positioning accuracy is improved, but indoor location determination fails due to electromagnetic radiation shielding in buildings

Engineering Contradiction:
Improvepositioning accuracyVSAvoidindoor location determination
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary system (terrestrial georeferencing functionality) to bridge the gap when satellite georeferencing fails indoors. This intermediary uses cellular network infrastructure (base stations, towers) as mediators to provide positioning information in environments where satellite signals are blocked, thus resolving the contradiction between outdoor positioning accuracy and indoor positioning reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a copy of georeferencing functionality adapted for indoor environments. Instead of relying on satellite-based georeferencing, it implements a terrestrial counterpart using cellular network infrastructure that replicates the positioning function specifically designed for indoor scenarios where satellite signals are unavailable

Inventive Principle:
Principle #26Copying

2Adaptability or versatility

If terrestrial georeferencing functionality is deployed in cellular networks, then indoor positioning capability is improved, but network complexity and deployment cost increase

Engineering Contradiction:
Improveindoor positioning capabilityVSAvoidnetwork deployment complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the cellular network infrastructure serve multiple functions: traditional voice/data communication plus positioning functionality. By enabling base stations and towers to provide both communication and georeferencing services, the system achieves indoor positioning capability without adding dedicated positioning infrastructure, thus reducing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The cellular network infrastructure serves itself by utilizing its existing components (base stations, towers, cell identifiers) to provide positioning services. The network uses its own infrastructure elements to determine user device locations, eliminating the need for external dedicated positioning systems and reducing deployment complexity

Inventive Principle:
Principle #25Self-service

3Quantity of substance

If tracing measurements are collected without valid positioning information, then data collection coverage is improved, but location determination accuracy deteriorates

Engineering Contradiction:
Improvedata collection coverageVSAvoidlocation determination accuracy
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent performs preliminary classification of tracing measurements into indoor and outdoor categories using speed estimates before attempting location determination. This preliminary action allows the system to process measurements with invalid positioning information differently based on their likely environment, improving overall location determination accuracy while maintaining broad data collection coverage

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the tracing measurements into different categories (indoor vs. outdoor) based on speed estimates and positioning information validity. This segmentation allows tailored processing methods for different measurement types, enabling accurate location determination for outdoor measurements while still utilizing indoor measurements for other purposes like signal quality assessment

Inventive Principle:
Principle #1Segmentation

4Productivity

If user devices move at high speeds, then data collection efficiency is improved, but position estimate accuracy deteriorates due to motion-induced positioning errors

Engineering Contradiction:
Improvedata collection efficiencyVSAvoidposition estimate accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic threshold adjustment for speed estimates based on individual user device characteristics and measurement conditions. Rather than using a fixed threshold, the system adapts the speed threshold dynamically, allowing high-speed moving devices to be identified and processed appropriately while maintaining accuracy for slower-moving devices, thus resolving the contradiction between data collection efficiency and position estimate accuracy

Inventive Principle:
Principle #15Dynamics

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

Accurately determines indoor locations of user devices, enabling the creation of quality-of-service maps and optimizing network parameters, even in environments with incomplete positioning information.

Implementation Method 1

determining position estimates of positions taken by the associated user device when performing the measurements of that measurement sequence

Methodology Applied
Scientific EffectEnhanced Cell ID positioning:

Implementation Method 2

determine an average speed estimate of the associated user device based on the respective position estimates

Methodology Applied
Scientific EffectKalman filtering:

Implementation Method 3

utilizing indoor expected powers based on electromagnetic propagation models

Methodology Applied
Scientific EffectElectromagnetic propagation:

Data Source

PatentEP4371316B1Method and system for determining indoor locations of user devices within a cellular network
Publication Date: 2025.12.10 TELECOM ITALIA SPA
  • EP4371316B1 patent drawingFigure 1
  • EP4371316B1 patent drawingFigure 2

AI summary

A method (200) is proposed. The method comprises: receiving (205), from a cellular network, measurements performed by user devices connected to the cellular network; identifying (215), among the measurements, a plurality of measurement sequences each one associated with a respective user device, each measurement sequence comprising the measurements performed by the associated user device in chronological order; for each measurement sequence, determining position estimates (220) of positions taken by the associated user device when performing the measurements of that measurement sequence; for each measurement sequence, determining an average speed estimate (225) of the associated user device based on the respective position estimates; determining, among the plurality of measurement sequences, first measurement sequences (230), the first measurement sequences comprising the measurement sequences, among the plurality of measurement sequences, for which the respective average speed estimates of the associated user devices are below a threshold speed; determining, among the first measurement sequences, second measurement sequences each one comprising at least one indoor measurement (235), the at least one indoor measurement of each second measurement sequence comprising at least one measurement, among the measurements of that second measurement sequence, that is associated with no positioning information or with an invalid positioning information, for each second measurement sequence, determining (240) an indoor location associated with the respective at least one indoor measurement, said determining an indoor location comprising refining the position estimate associated with the at least one indoor measurement.