Wireless Device Location Mapping via Iterative Sphere Expansion
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Solution Overview
Problem
Current mechanisms for determining the location of wireless devices in indoor environments, such as GPS and Wi-Fi positioning systems, suffer from inaccuracies due to signal attenuation and multipath issues, failing to provide precise location coordinates necessary for applications like device and network security, threat detection, and location-aware services.
Innovation Solution
The method employs stepwise trilateration using scalar range estimates, generating highly accurate location estimates and contour plots by iteratively adjusting the radii of spheres around sensor devices to ensure accurate intersection points, even with fewer than three intersection points, and uses kernel density estimation to refine location accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional trilateration methods are used for location determination, then the system complexity is low, but the measurement precision of device location is insufficient
Solution Approach 1:
The patent segments the location determination process into multiple iterative steps: initial range estimation, contour plot generation, intersection point identification, and kernel density estimation. Each step refines the location estimate progressively, transforming a single complex trilateration problem into multiple manageable processing stages that improve accuracy without overwhelming system complexity
Solution Approach 2:
The patent introduces contour plots as an intermediate dimensional representation between raw signal data and final location coordinates. By mapping range estimates onto contour plots and identifying intersection points across multiple contours, the system adds a visual and computational dimension that enhances location precision beyond traditional direct trilateration methods
2Reliability
If GPS and Wi-Fi positioning systems are used in indoor environments, then basic location tracking is enabled, but signal attenuation and multipath issues cause location inaccuracies
Solution Approach 1:
The patent introduces contour plots as an intermediary representation that mediates between raw signal measurements and final location determination. The contour plots visualize range estimates from multiple sensors and their intersections, providing a robust intermediate step that filters out the effects of signal attenuation and multipath propagation before final location calculation
Solution Approach 2:
The patent replaces direct reliance on physical signal propagation characteristics (which are affected by attenuation and multipath) with a mathematical field-based approach using contour plots and kernel density estimation. This substitution transforms the problem from one dependent on physical signal integrity to one based on statistical and geometric analysis, thereby overcoming the harmful effects of indoor signal degradation
3Reliability
If comprehensive device location mapping is implemented for security monitoring, then threat detection capability is improved, but the computational resources and time required increase
Solution Approach 1:
The patent performs preliminary actions by pre-generating contour plots from range estimates and pre-identifying potential intersection points before final location determination is needed. This preliminary processing organizes the data in advance, so that when threat detection is required, the system can quickly query pre-computed contour intersections rather than performing full trilateration calculations in real-time, reducing computational time for security responses
Data Source
AI summary
A system and method of wireless device location mapping comprising measuring a signal strength of a wireless signal generated by the wireless device at a plurality of sensor devices positioned at a plurality of sensor locations; determining a range from each of the plurality of sensor devices to the wireless device based on the measured signal strength; and generating a plurality of ranging spheres, a respective one of the plurality of ranging spheres corresponding a respective one of the plurality of sensor devices and being centered at a respective one of the plurality of sensor locations and having a radius that is proportional to the determined range of the respective one of the plurality of sensor devices to the wireless device. The system and method further comprises generating a new radius for each of the plurality of ranging spheres by expanding the radius for each of the plurality of ranging spheres by a small increment while maintaining a ratio between any two of the radii of the plurality of ranging spheres, determining a number of intersection points and adding a location of each of the intersection points to a map.