Scientists in Germany have demonstrated a startling new form of surveillance: identifying people using nothing more than ordinary WiFi signals. By analyzing how radio waves bounce around a room, researchers can effectively “see” and recognize individuals — even if they are not carrying a device and even if their phone is turned off.
Any reason this wouldn’t work with cell towers?
There’s no need, they can use triangulation since you’re almost always near your phone
I imagine revolution decreases with range
Revolution should increase the closer you get to a billionaire.
I think the main advantage with the wifi-based approaches is that they are usually used in a relatively static/calm indoor environment with a stable channel response and your motions are disturbing that, compared to a quickly changing outdoor environment (e.g. a city) where it would be much harder to distinguish individuals. Also, you are typically closer to the access points, making the power/SNR higher. Regarding mobile communication though, the trend is towards higher frequencies and smaller cell sizes which also give greater spatial resolution (and higher power) and some funky near-field effects can be used to get beam forming on crack: https://arxiv.org/abs/2407.10147 So perhaps it could work even better, wouldn’t be surprised