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Device type not known ? #44

Open mca92 opened 4 years ago

mca92 commented 4 years ago

Hello,

It is not intended to broadcast the device type in the Hello message.

Thera are hundreds of smartphone models that emit in Bluetooth with different signal levels. Without knowing the device type that emitted the Hello message, how will it be possible to estimate the distance, with a sufficient precision ?

Thanks.

Matioupi commented 4 years ago

My best guess is that with or without the phone model, you cannot make an accurate distance estimation. Some phones will be inside a hand bag with additional attenuation. Some will be seen though a glass window (e.g. from train to dock) and anyway, the antennas radiation patterns are far from spherical /isotropic, so without knowing also the relative attitude of both phones, nothing accurate can be done.

FrankGrimm commented 4 years ago

If they follow the currently available PEPP-PT client side implementation it looks like, while not included in the Bluetooth communication, several hardware and software identifiers are shared with the backend infrastructure that does the matching.

peg500and commented 4 years ago

All the batteries are not strong enough to use bluetooth for more than one hour, all the people don't have a brown new phone

PRIVATICS-Inria commented 4 years ago

This is a very good question, but we are not in charge of this part and cannot provide any insight. But great care should be paid not to provide too much information...