Population Estimation Using Pseudo Signals for Power-Off Gaps

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Solution Overview

Problem

Existing population estimation methods using mobile terminal location registration signals are prone to errors due to power-off of mobile terminals, leading to underestimation or overestimation of actual population in event sites where many users gather.

Innovation Solution

A population estimation device that interpolates pseudo signals during absent periods due to power-off and excludes initial signals post-absent period to correct population estimates, using a signal acquisition unit and estimation unit to aggregate and adjust data based on location registration signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If location registration signals are used for population estimation, then population estimation can be performed using mobile terminal data, but estimation error increases when mobile terminals are turned off or turned on simultaneously

Engineering Contradiction:

Improvepopulation estimation accuracyVSAvoidestimation stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system performs preliminary actions by detecting absent periods (when mobile terminals are turned off) and interpolating pseudo signals to compensate for missing data. This preliminary compensation prevents the underestimation that would otherwise occur during absent periods, thereby improving measurement precision without compromising reliability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by monitoring the transmission timing of location registration signals and detecting absent periods. Based on this feedback, the system dynamically adjusts the population estimation by interpolating pseudo signals for absent periods and excluding burst signals, thereby maintaining both measurement precision and estimation stability

Inventive Principle:

Principle #23Feedback

2Ease of operation

If mobile terminals are turned off during events, then users can enjoy the event without mobile device interruptions, but location registration signals are not transmitted causing population underestimation

Engineering Contradiction:

Improveuser convenience during eventsVSAvoidpopulation estimation accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The system converts the harmful effect of missing location registration signals (caused by mobile terminals being turned off during events) into a beneficial solution by detecting absent periods and interpolating pseudo signals. This approach allows users to enjoy events with mobile terminals turned off while maintaining accurate population estimation

Inventive Principle:

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

Solution Approach 2:

The system performs preliminary detection of absent periods and interpolates pseudo signals to compensate for missing data before final population estimation is calculated. This preliminary action ensures that population underestimation due to mobile terminals being turned off does not occur, thereby maintaining measurement precision while preserving user convenience

Inventive Principle:

Principle #10Preliminary action

3Productivity

If many mobile terminals are turned on simultaneously after events, then users can resume normal activities, but a very large number of location registration signals are transmitted instantaneously causing population overestimation

Engineering Contradiction:

Improvesignal transmission efficiencyVSAvoidpopulation estimation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The system extracts and identifies burst signals that occur when many mobile terminals are turned on simultaneously after events. By detecting the characteristic timing pattern of burst signals, the system selectively excludes these signals from population estimation calculations, thereby eliminating population overestimation while preserving normal signal transmission efficiency

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses feedback from signal transmission timing analysis to identify burst patterns. When burst patterns are detected (indicating simultaneous mobile terminal power-on after events), the system automatically adjusts the estimation by excluding these signals, thereby maintaining measurement precision without affecting overall signal transmission efficiency

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12568345B2Population estimation device

Publication Date: 2026.03.03 NTT DOCOMO INC

AI summary

A population estimation server 10 according to an embodiment includes a signal acquisition unit 11 that acquires a location registration signal periodically transmitted from a mobile terminal 20 carried by a user, and an estimation unit 12 that aggregates the acquired location registration signals for each area and for each estimation-unit-period and estimates a population for each area and for each estimation-unit-period based on an aggregation result. When an absent period in which the signal from the mobile terminal 20 staying in a target area is not acquired occurs after the location registration signal from the mobile terminal 20 is acquired, the estimation unit 12 interpolates a pseudo signal associated with the mobile terminal 20 in the absent period, and aggregates signals while excluding a location registration signal first transmitted from the mobile terminal after the absent period from an aggregation target.