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| Bluetooth Low Energy is unsuitable for COVID-19 contact tracing, say inventors |
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| cdev:
In particular, its problems will lead to many false positives and negatives they say. https://theintercept.com/2020/05/05/coronavirus-bluetooth-contact-tracing/ |
| m98:
Which is kind-of obvious. Getting reliable meter-level ranging from single RSSI measurements with dissimilar devices, antenna orientations, from a body-worn device, in a multipath environment with a multitude of obstacles. It just sounds like a dead-end idea from the beginning. Maybe its good enough to tell if people where together in the same room/building. |
| SiliconWizard:
Indeed. It's flawed. It's not even 100% good enough to tell if people were nearby at some point. There are tons of reasons why in some particular conditions, detection would fail, and especially in crowded places with a lot of radio devices. I have no idea of the average "detection" % in real-life settings. In a past project, we had implemented BLE and depending on conditions, it could get finicky. Detecting ALL devices in range could take sometimes several minutes, which may not be compatible with people moving around. |
| jogri:
Well, if you would combine BLE with GPS and the gyrometer/inertial measurement unit you could get rather accurate histograms of a persons position. If another device gets registered via BLE you wait until the signal drops out and then compare the (more or less) exact position of both persons over the time they were in proximity. Should yield way better results (you basically eliminate the RSSI/walls issue), but you would have to share your movement/exact position with everyone in your proximity-> won't happen as it would be a data security/privacy nightmare. One possible way to improve the current system would be to install BLE beacons in highly frequented areas that just announce their exact position (+transmission strength)->the app could determine the RSSI of an object that is x meters away if it compares the location of the beacon against its own GPS signal-> triangulation, that would partly counteract the problem that your body is reducing the signal strength in some directions. |
| mark03:
In most western countries, GPS has been ruled out over privacy concerns. I think the BLE-alone approach is the only alternative seriously being considered. (Actually deploying it would require a country with at least a basic minimum level of faith in government, and functional high-level decision making, i.e. not the U.S.) Clearly BLE is not perfect, but it doesn't have to be perfect. It only has to be better than the [achievable] alternatives. Anyway, the thread title is an unfair characterization (sorry, characterisation ;)) of the article, the title of which was --- Quote ---The Inventors of Bluetooth Say There Could Be Problems Using Their Tech for Coronavirus Contact Tracing --- End quote --- |
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