Passive Wi-Fi Sensor Tracking via Spoofed Beacon Frames
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional asset tracking systems require dedicated hardware and software, are costly, and difficult to deploy and manage, especially in widespread locations, as they need to be intentionally deployed and actively managed, which is impractical and expensive.
Innovation Solution
A method and system for passive asset tracking using existing Wi-Fi infrastructure, where moveable assets are tracked by unrelated wireless devices that come into range of Wi-Fi access points, without the devices or users being aware, leveraging the Wi-Fi wireless network discovery protocol and smartphones' ability to report location and access point information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dedicated hardware and software are deployed for asset tracking, then tracking reliability is improved, but device complexity and deployment cost increase
Solution Approach 1:
The patent makes existing Wi-Fi infrastructure perform dual functions: its original networking function plus asset tracking. Wi-Fi access points and client devices continue to provide network connectivity while simultaneously enabling passive tracking of moveable assets through their normal connection and disconnection patterns, eliminating the need for dedicated tracking hardware.
Solution Approach 2:
The system leverages the self-reported data from Wi-Fi clients about their own connections and disconnections to track assets. The infrastructure serves itself by using its existing operational data (connection events, signal strength, location information) to provide tracking functionality without requiring additional sensors or active participation from tracked objects.
2Measurement precision
If dedicated tracking infrastructure is deployed, then tracking precision is improved, but loss of energy and operational cost increase
Solution Approach 1:
The patent uses Wi-Fi access points as intermediaries to enable tracking without direct communication between the tracking system and the asset. The access points mediate by detecting when devices connect or disconnect from their networks, providing location and movement information through these connection events without requiring the tracked asset to actively report its position.
Solution Approach 2:
The system creates a virtual model of asset movement by copying and analyzing existing Wi-Fi connection data. Instead of directly measuring asset position with dedicated sensors, the system reconstructs location information from patterns in Wi-Fi association and disassociation events that already occur during normal device operation.
3Ease of operation
If passive tracking using Wi-Fi infrastructure is implemented, then ease of operation is improved, but measurement precision may deteriorate
Solution Approach 1:
The system uses periodic Wi-Fi beacon transmissions and connection event reporting to continuously update asset location. Wi-Fi access points periodically broadcast beacons, and client devices periodically report their connection status and location information, creating a series of discrete measurement points that collectively provide continuous tracking capability.
Solution Approach 2:
The tracking system adapts to dynamic conditions by utilizing real-time Wi-Fi signal strength measurements and connection status changes. As devices move in and out of range of different access points, the system dynamically updates location estimates based on which access points detect the device's presence, adjusting tracking precision according to environmental conditions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of passive sensor tracking with existing infrastructure includes associating unique identifying information of a Wi-Fi access point of a passive sensor with a physical property to be sensed by the passive sensor, where the Wi-Fi access point transmits a spoofed beacon frame, probe response frame, or other management frame as part of Wi-Fi wireless network discovery that includes sensor data. The method further includes receiving sensor data, including the physical property sensed by the passive sensor, in the spoofed beacon frame, probe response frame, or other management frame that the passive sensor transmits, as part of Wi-Fi wireless network discovery, to a wireless device that encounters the passive sensor, where the wireless device reports, either directly or indirectly, the unique identifying information of the Wi-Fi access point encountered and the sensor data in the spoofed beacon frame, probe response frame, or other management frame.