WLAN Positioning via RSSI Intersection Mapping

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current indoor positioning technologies for intelligent devices rely on estimating distances using Received Signal Strength Indicator (RSSI) information, which can be inaccurate due to signal attenuation and external factors, limiting the precision of device location determination in WLAN-based systems.

Innovation Solution

A method and device that collect RSSI information from point-to-point messages between devices to derive relative location maps, using circles centered at each device to determine precise positions by calculating distances and intersections, enhancing accuracy and flexibility in positioning multiple intelligent devices within a WLAN network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If distance estimation is performed using RSSI information and empirical formulas, then positioning can be implemented in WLAN-based systems, but positioning accuracy deteriorates due to signal attenuation and external factors

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsignal attenuation and external factors
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the positioning process into multiple independent distance estimation measurements between different device pairs. Instead of relying on a single RSSI measurement from one access point, the system performs multiple pairwise distance estimations between the mobile terminal and multiple intelligent devices, then combines these segmented measurements to determine position through geometric intersection, thereby reducing the impact of signal attenuation and external factors on any single measurement.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If multiple intelligent devices are deployed in a room for separate control and management, then positioning functionality is enabled, but system complexity increases

Engineering Contradiction:
Improvedevice management capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal positioning framework where intelligent devices serve multiple functions: they act as both controlled smart home devices and as positioning reference points. The same WLAN infrastructure and communication protocols used for device control are also utilized for positioning, eliminating the need for separate positioning hardware or protocols. This multi-functional approach enables positioning capability while avoiding additional system complexity.

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

3Ease of manufacture

If distance estimation uses empirical formulas based on signal strength, then positioning can be achieved without additional hardware, but measurement precision deteriorates due to environmental factors

Engineering Contradiction:
Improveimplementation simplicityVSAvoiddistance estimation accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent merges multiple distance estimation results from different device pairs into a unified position determination. By combining the geometric information from multiple independent measurements (forming circles around each device based on estimated distances), the system achieves more accurate positioning than any single measurement could provide, while still using only software-based empirical formulas without additional hardware.

Inventive Principle:
Principle #5Merging (Combining)

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

This approach provides high-accuracy positioning of mobile terminals and intelligent devices by plotting relative location maps based on collected RSSI information, accounting for signal attenuation and external factors, and allows for seamless integration of new devices into the network.

Implementation Method 1

estimating distance between an access point (AP) at wireless signal transmitter side and the intelligent device by using an empirical formula between signal strength and distance

Methodology Applied
Scientific EffectSignal attenuation: Absorption (EM radiation)

Data Source

PatentEP3297345B1Wireless local area network based positioning method and device
Publication Date: 2022.01.26 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3297345B1 patent drawingFigure 1~2
  • EP3297345B1 patent drawingFigure 3
  • EP3297345B1 patent drawingFigure 4

AI summary

The present disclosure provides a wireless local area network based positioning method and device. The method includes: acquiring (101) first RSSI information and at least one second RSSI information; receiving (102) at least one third RSSI information reported by a mobile terminal; receiving (103) at least one fourth RSSI information reported by at least one intelligent device; performing (104) positioning of the mobile terminal, a routing device, and the at least one intelligent device based on the first RSSI information, the at least one second RSSI information, the at least one third RSSI information, and the at least one fourth RSSI information.