Problems using bluetooth to check distance between users ?

[studiot]

Several countries have tried using Bluetooth to measure soical distancing distances.

None (to my knowledge) have found a successful method.

So what are the problems they are facing ?

[Sensei]

1 hour ago, studiot said:

Several countries have tried using Bluetooth to measure soical distancing distances.

None (to my knowledge) have found a successful method.

So what are the problems they are facing ?

Bluetooth works reliablely only a few meters. If you run app in continuous BT discovery mode the all other devices with enabled BT will be captured (unless they have disabled BT, or enabled airplane mode). So app knows which devices (and indirectly which people) were around you (and their phone's BT MAC addresses). And if person is ill the all people with close proximity (5-10m) will be identified (if government app would send MAC address to central server).

The problem with this method is that the all people have to have smartphone, and all have to have installed application, and must have battery fully charged, and never exhaust it.. continuous usage of BT drains battery very quickly. To make application work, device can't go to sleep mode. My device especially not liking WiFi, and GPS, but BT is third to drain battery..

Obviously there is (well deserved!) reluctance from democratic countries people concerning about their privacy. Therefore even Android app which asks for Bluetooth permission also requires coarse location permission, since Android v10, fine location permission, and since Android v11, background location permission.

As a side note, if you have WiFi turned on, Hotspot mode or not, MAC address can also identify your device (it is unique in the world). But WiFi and BT have different MAC addresses.

So, entire idea of usage of BT could work only in totalitarian country, like North Korea etc. (if they would have electronic devices and electricity all day long)

 

Edited January 24, 2021 by Sensei

[John Cuthber]

19 hours ago, Sensei said:

So, entire idea of usage of BT could work only in totalitarian country, like North Korea etc

... and the UK

https://covid19.nhs.uk/pdf/introducing-the-app.pdf

... where it works badly