Positioning Timing Selection for Low-Battery Wireless Localization

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Solution Overview

Problem

Existing methods for determining the position of wireless terminal devices through radio wave emissions lead to significant battery drain due to excessive radio wave emissions or reduced frequency and accuracy of positioning updates when intervals are thinned out, and require additional functions or specialized access points.

Innovation Solution

A position determination timing selection device and method that selects optimal times for radio wave emissions based on channel measurements by multiple devices, reducing unnecessary emissions and battery drain without adding new functions to the terminal device or access point.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the wireless terminal device emits radio waves frequently for positioning, then the positioning accuracy and update frequency are improved, but the battery drain increases significantly

Engineering Contradiction:

Improvepositioning accuracyVSAvoidbattery drain

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Instead of having the terminal device actively emit radio waves for positioning, the system inverts the approach by having measurement devices receive and measure radio waves from the terminal device. The terminal device only transmits positioning radio waves when triggered by a response request packet from the network side, significantly reducing its transmission frequency and energy consumption while maintaining positioning capability through passive measurement by external devices.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces measurement devices as intermediaries between the terminal device and the positioning system. These measurement devices receive and measure the positioning radio waves emitted by the terminal device, eliminating the need for the terminal device to continuously emit high-power radio waves. The measurement devices act as mediators that enable accurate positioning with minimal energy consumption from the terminal device.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If the wireless terminal device emits radio waves infrequently to save battery, then the battery drain is reduced, but the positioning update frequency and accuracy are reduced

Engineering Contradiction:

Improvebattery drainVSAvoidpositioning update frequency

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The system implements periodic positioning updates triggered by response request packets sent from the network side at predetermined intervals. This periodic triggering ensures that the terminal device emits positioning radio waves at regular intervals, maintaining consistent positioning update frequency and accuracy while minimizing transmissions to only when necessary, thus optimizing battery usage.

Inventive Principle:

Principle #19Periodic action

3Use of energy by moving object

If new functions are added to the wireless terminal device to enable power-saving positioning, then the positioning efficiency is improved, but the device complexity increases

Engineering Contradiction:

Improvepower consumptionVSAvoiddevice functionality

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent makes the network side and measurement devices responsible for initiating and performing positioning measurements, rather than requiring the terminal device to actively manage positioning operations. The terminal device simply responds to network triggers by emitting positioning radio waves, while the measurement devices perform the actual measurements. This self-service approach at the network level eliminates the need for complex positioning management functions in the terminal device.

Inventive Principle:

Principle #25Self-service

4Measurement precision

If beacon frames are transmitted frequently to enable positioning in power-saving mode, then the positioning capability is maintained, but the radio wave emissions increase causing battery drain

Engineering Contradiction:

Improvepositioning capabilityVSAvoidbattery drain

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

Instead of requiring the terminal device to emit radio waves continuously or at every beacon frame interval, the system uses partial action by triggering emissions only when response request packets are received. The measurement devices perform measurements based on these triggered emissions rather than requiring continuous terminal device transmissions, achieving sufficient positioning capability with minimal energy expenditure from the terminal device.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12628117B2Position determination timing selection device, wireless communication system, position determination timing selection method, and recording medium

Publication Date: 2026.05.12 NEC CORP

AI summary

Channel identification information indicating a channel measured by each of a plurality of measurement devices that measure a radio wave strength of radio waves propagating in the channel used by a wireless terminal device for radio wave transmission, and information indicating a measurement time at which the measurement was performed are acquired. For each channel, a time at which number of the measurement devices performing measurement satisfies a predetermined condition defined in advance is selected based on the acquired channel identification information of each measurement device and the information indicating the measurement time. A position determination time for each channel from each selected time is selected, and the channel identification information indicating the channel used by the wireless terminal device subject to position determination is acquired.