Wireless Device Location Tracking Using Anchor and Attractor Access Points
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Solution Overview
Problem
Conventional location tracking systems require a time-consuming calibration phase and are prone to inaccuracies due to obstacles and variations in device types, leading to unreliable location determination, especially in dynamic environments like indoor spaces and outdoor areas with seasonal changes.
Innovation Solution
A method that estimates the location of a wireless device by identifying an anchor access point with the highest signal strength and designating other access points with signal strengths above a threshold as attractor points, calculating a pull point along a line from the anchor to the attractor, and averaging these locations to determine the device's position without the need for a calibration phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a calibration phase is used to build a radio map for location tracking, then location determination can be performed, but the process becomes time-consuming and inaccurate due to obstacles and device variations
Solution Approach 1:
The patent extracts and eliminates the calibration phase entirely from the location tracking system. Instead of requiring a time-consuming calibration process to build radio maps, the system directly calculates device location by comparing signal strength data from multiple access points against known access point locations, achieving both time efficiency and acceptable accuracy
Solution Approach 2:
The system performs preliminary setup by storing known locations of access points in advance, but eliminates the need for preliminary calibration with actual devices. The location calculation can proceed immediately using signal strength comparisons without requiring pre-captured signal samples at various calibration points
2Reliability
If signal strength samples are captured at calibration points to build a radio map, then location prediction is possible, but obstacles like human bodies and moved objects disrupt the results and reduce reliability
Solution Approach 1:
Instead of capturing signal strengths at fixed calibration points and expecting devices to match those patterns (which fails when obstacles move), the patent inverts the approach: it uses the known fixed locations of access points and compares actual signal strengths directly to calculate device position, making the system adaptive to changing environmental conditions rather than rigidly dependent on pre-captured calibration data
Solution Approach 2:
The system transitions from a static calibration-based approach to a dynamic real-time calculation approach. Location is continuously determined by comparing current signal strength measurements against known access point locations, allowing the system to adapt automatically to environmental changes such as moved objects or seasonal variations without requiring recalibration
3Adaptability or versatility
If different device types with varying antenna configurations are used, then device versatility is improved, but signal strength values vary making universal location determination difficult
Solution Approach 1:
The patent creates a universal location determination method that works across different device types without requiring device-specific calibration. By using the known locations of access points as the reference framework and comparing signal strengths relatively, the system achieves multi-device compatibility without sacrificing location accuracy, eliminating the need for separate radio maps for each device type
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 accurate location estimation within a few to ten feet, suitable for indoor environments where GPS signals are unavailable, and allows for applications such as directing offers to users based on proximity to products or tracking people within buildings, without relying on universal mapping algorithms or prerecorded signal strength information.
Implementation Method 1
receiving signal strength data from a plurality of access points
Data Source
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AI summary
One or more systems, devices, and/or methods for tracking a wireless device are disclosed. For example, a method includes receiving signal strength data for each of a plurality of access points. The signal strength data from the plurality of access points is compared to identify an anchor access point having a highest signal strength. Remaining signal strength data from the plurality of access points are compared to a threshold signal strength to identify at least one attractor access point. A memory is accessed for locations of the anchor access point and the at least one attractor access point. A pull point is calculated along a line from the anchor access point to the at least one attractor access point. A location of the wireless device is estimated as an average of the pull point and the location of the anchor access point.