comments are focusing on the protocol's message content which is not the source of the ability to track broadcasters. The ability comes from detecting nuances in the RF signal:
>BLE [snip] imperfections are introduced by the shared I/Q frontend of the chipset (Figure 1). They result in two measurable
metrics in BLE and WiFi transmissions: Carrier Frequency Offset (CFO) and I/Q imperfections, specifically: I/Q offset and I/Q imbalance.
>BLE [snip] imperfections are introduced by the shared I/Q frontend of the chipset (Figure 1). They result in two measurable metrics in BLE and WiFi transmissions: Carrier Frequency Offset (CFO) and I/Q imperfections, specifically: I/Q offset and I/Q imbalance.
links to the paper:
https://cseweb.ucsd.edu/~nibhaska/papers/sp22_paper.pdf
https://www.researchgate.net/publication/360655420_Evaluatin...
Git repo: https://github.com/ucsdsysnet/blephytracking