Wireless Device Locationing via Fine Timing Measurement
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Solution Overview
Problem
Traditional Wi-Fi positioning methods, such as RSSI fingerprinting, lack accuracy and require manual configuration, making them ineffective for indoor location estimation and security risk detection in wireless networks.
Innovation Solution
The implementation of the IEEE 802.11mc-2016 Fine Timing Measurement (FTM) protocol, which enables devices to measure Round Trip Time (RTT) to determine distances and locations, using multiple access points and software access points to support FTM procedures, even in non-natively supported devices, for precise device detection and location tracking within a wireless network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional Wi-Fi positioning methods (RSSI fingerprinting) are used, then device location estimation can be performed, but the positioning accuracy is insufficient and manual configuration is required
Solution Approach 1:
The patent replaces traditional RSSI-based positioning with Fine Timing Measurement (FTM) protocol that uses precise time-of-flight measurements of wireless signals. This substitution of the measurement mechanism achieves meter-level positioning accuracy without requiring manual RSSI fingerprint configuration, automatically determining device locations through timestamp-based RTT calculations between access points and client devices
Solution Approach 2:
The patent changes the fundamental measurement parameter from signal strength (RSSI) to time-of-flight (ToF). By measuring the round-trip time of FTM frames between devices and using the speed of light to calculate distance, the system achieves superior positioning accuracy. The parameter change from power-based to time-based measurement eliminates the need for manual configuration while providing precise location estimation
2Measurement precision
If FTM protocol is implemented for precise location measurement, then positioning accuracy improves to one-meter level, but device complexity increases due to protocol requirements
Solution Approach 1:
The patent implements FTM capability in software access points, allowing standard access points without native FTM hardware support to participate in precise positioning. This multi-functionality approach enables both natively supported and non-natively supported devices to perform FTM measurements, reducing the complexity burden on individual devices while maintaining high positioning accuracy across the network
Solution Approach 2:
The patent uses software access points as intermediaries that can translate or facilitate FTM protocol operations for devices that lack native FTM support. This intermediary layer allows the precise positioning functionality to be extended to broader device ecosystems without requiring every device to implement the complex FTM protocol natively, thus managing system complexity while achieving high measurement precision
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
Achieves up to one-meter position accuracy and effectively detects rogue devices by mapping device locations within a network, enhancing security and network coverage analysis.
Implementation Method 1
measuring a Round Trip Time (RTT) between a set of wireless devices based on time-of-flight
Data Source
AI summary
Technologies directed to device detection and locationing are described. One method includes establishing a first wireless connection between a first wireless device and a second wireless device on a first channel. The first wireless device sends to the second wireless device a first indication that the first wireless device is to operate in an off-channel mode with a third wireless device at a first location a Fine Timing Measurement (FTM) procedure. The first wireless device performs a first FTM process between the first wireless device and the third wireless device. The first device determines first timing data including a signal round trip time (RRT) associated with the first FTM process and determines a first distance between the first wireless device and the third wireless device based on the first timing data. A second location of the first wireless device is determined using the first distance.