WLAN Speed and Direction Estimation via Signal Analysis
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Solution Overview
Problem
Existing WLAN-based positioning systems are ineffective in estimating speed and direction of travel in outdoor and wide-area scenarios due to challenges such as varying radio propagation, lack of detailed site surveys, and constant communication channel requirements, which are not feasible in metropolitan areas.
Innovation Solution
A method that utilizes WLAN access points to estimate speed and direction by measuring signal strengths and variations over time, using a reference database to calculate geographic locations and associate them with time values, and employing techniques like numerical derivatives and Fourier transforms to determine user movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If indoor WLAN positioning systems use detailed site surveys and constant network connection to achieve high accuracy, then positioning accuracy is improved, but device complexity and deployment difficulty increase significantly for wide-area scenarios
Solution Approach 1:
The patent divides the positioning system into two independent components: a positioning engine that runs locally on mobile devices using only onboard sensors and WLAN MAC addresses, and a separate mapping system that creates virtual floor plans. This segmentation eliminates the need for complex centralized infrastructure and detailed site surveys, allowing deployment in wide-area scenarios while maintaining positioning accuracy through local computation.
Solution Approach 2:
The positioning engine performs self-calibration and adaptive learning by continuously analyzing sensor data and WLAN signal characteristics from multiple devices. The system automatically adjusts to environmental conditions and improves positioning accuracy over time without requiring manual site surveys or constant network connection for calibration, enabling autonomous operation in diverse environments.
2Reliability
If WLAN positioning systems require constant network connection for synchronization information, then positioning reliability is improved, but adaptability to wide-area outdoor scenarios deteriorates
Solution Approach 1:
The system performs preliminary actions by pre-processing WLAN signal data and creating virtual floor plans during initial deployment, storing them locally on devices. This allows the positioning engine to operate independently without constant network connection, maintaining reliability through locally cached reference data while adapting to outdoor and wide-area scenarios where continuous connectivity is unavailable.
Solution Approach 2:
The positioning system dynamically adapts to different environments by continuously learning from sensor data and adjusting its algorithms based on local conditions. The system can operate in various modes (network-connected or offline) and automatically transitions between them, maintaining reliability through adaptive behavior rather than requiring constant network connection for synchronization.
3Measurement precision
If indoor positioning systems conduct detailed site surveys of every area, then measurement accuracy is improved, but loss of time and resources increases for wide-area deployment
Solution Approach 1:
The patent creates virtual copies of physical environments through computer-generated virtual floor plans that replicate spatial relationships and WLAN signal characteristics. These virtual models serve as reference data for positioning without requiring physical site surveys, dramatically reducing deployment time while maintaining positioning accuracy through algorithmic mapping rather than manual measurement.
Solution Approach 2:
The system transforms the positioning approach by changing from physical measurement parameters (requiring detailed site surveys) to computational parameters (using sensor fusion and WLAN MAC address triangulation). This parameter change enables rapid deployment in wide-area scenarios while maintaining accuracy through mathematical modeling rather than physical measurement of every location.
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AI summary
A method for estimating the speed and bearing of a Wi-Fi enabled device using WLAN radio signals in a WLAN based location service is provided. A method used to estimate a speed of travel of a Wi-Fi enabled device comprises the Wi-Fi enabled device receiving signals transmitted by Wi-Fi access points in range of the Wi-Fi enabled device, and using the signals to estimate the speed of and/or direction of travel of the Wi-Fi enabled device.