3 ms·

I'll admit I'm not an expert in this area, but why are apps using Bluetooth useless? Because people turn Bluetooth off?

aaron695 6y ago
On the iPhone it just goes to sleep. This is a killer. But it's not the end of it. Bluetooth can't measure distance well, it's totally not in it's design. Every phone model is different, I think including software version. So there are databases of phone models to try and fix this. But it's still far from perfect since it's still not in the Bluetooth design. Measuring time of exposure is hard with Bluetooth. Now Apple and Android released frameworks to try and fix these issues. But governments had already invested in the old solution and it's not clear if the new framework will fix much. To do what they want to do with Bluetooth would be pretty amazing. It's basically Geo Location using beacons using existing phone tech. That's fucking cool, yet for some reason it's never been done before this, Covid solves all technological issues it seems? GPS tracking works really well. You will also know where. So you can see if it was inside, outside, walls between them, all things vague Bluetooth apps can't do. Lot's of context with GPS. So, what do we think governments will do when Bluetooth has been shown not to work, but this privacy invading app works really well, which it should.
taejo 6y ago
Measurement-Based Evaluation Of Google/Apple Exposure Notification API For Proximity Detection In A Commuter Bus https://arxiv.org/pdf/2006.08543.pdf https://arxiv.org/pdf/2006.08543.pdf "We find that the attenuation level reported by the GAEN API need not increase with distance between handsets, consistent with there being a complex radio environment inside a bus caused by the metal-rich environment... Applying the rule used by the Swiss Covid-19 contact tracing app to trigger an exposure notification to our bus measurements we find that no exposure notifications would have been triggered despite the fact that all pairs of handsets were within 2m of one another for at least 15 mins"
- raziel2p 6y ago
  I wish they would've tested more distances. If the threshold is 1.5 meters or even 1.0 meters that's still better than nothing at all. No one is touting these apps (or masks, or social distancing) as the ultimate solution to the spread of SARS-CoV-2, it's all just things we can do to reduce the risk.
  - aaron695 6y ago
    > I wish they would've tested more distances. Bluetooth is 31 years old. What is there to test? > No one is touting these apps <snip> it's all just things we can do to reduce the risk. The app does not reduce risk, even if it worked. It's for contact tracing. This is importantly different. You seem confused, which I might guess is because the app was touted incorrectly in many countries. Masks and social distancing do reduce risk. Although most Western countries told you otherwise to begin with on masks. And told you incorrectly how to wash hands, and also incorrectly said it reduces risk (considered unlikely). I'll add being outdoors also probably reduces risk, not sure this is commonly touted yet.
    - raziel2p 6y ago
      I mean risk at the societal level, not individual. Maybe there's a better word. Anyway what I mean is that the risk of the virus/disease spreading faster than our healthcare systems can handle is lowered by effective contact tracing. Not that I personally am less at risk of being infected if I install the app.
      - aaron695 6y ago
        Ok, some politicians etc were calling the apps a condom or sunscreen. All evidence since March has been boots on the ground for contact tracing is what's important. Not tech. But the Bluetooth apps, which we know can't work well also don't try for behaviour change, they might even increase risk. This app at this college is trying for positive behaviour change.

On the iPhone it just goes to sleep. This is a killer. But it's not the end of it. Bluetooth can't measure distance well, it's totally not in it's design. Every phone model is different, I think including software version. So there are databases of phone models to try and fix this. But it's still far from perfect since it's still not in the Bluetooth design. Measuring time of exposure is hard with Bluetooth. Now Apple and Android released frameworks to try and fix these issues. But governments had already invested in the old solution and it's not clear if the new framework will fix much. To do what they want to do with Bluetooth would be pretty amazing. It's basically Geo Location using beacons using existing phone tech. That's fucking cool, yet for some reason it's never been done before this, Covid solves all technological issues it seems? GPS tracking works really well. You will also know where. So you can see if it was inside, outside, walls between them, all things vague Bluetooth apps can't do. Lot's of context with GPS. So, what do we think governments will do when Bluetooth has been shown not to work, but this privacy invading app works really well, which it should.

taejo 6y ago

Measurement-Based Evaluation Of Google/Apple Exposure Notification API For Proximity Detection In A Commuter Bus https://arxiv.org/pdf/2006.08543.pdf https://arxiv.org/pdf/2006.08543.pdf "We find that the attenuation level reported by the GAEN API need not increase with distance between handsets, consistent with there being a complex radio environment inside a bus caused by the metal-rich environment... Applying the rule used by the Swiss Covid-19 contact tracing app to trigger an exposure notification to our bus measurements we find that no exposure notifications would have been triggered despite the fact that all pairs of handsets were within 2m of one another for at least 15 mins"

raziel2p 6y ago
I wish they would've tested more distances. If the threshold is 1.5 meters or even 1.0 meters that's still better than nothing at all. No one is touting these apps (or masks, or social distancing) as the ultimate solution to the spread of SARS-CoV-2, it's all just things we can do to reduce the risk.
- aaron695 6y ago
  > I wish they would've tested more distances. Bluetooth is 31 years old. What is there to test? > No one is touting these apps <snip> it's all just things we can do to reduce the risk. The app does not reduce risk, even if it worked. It's for contact tracing. This is importantly different. You seem confused, which I might guess is because the app was touted incorrectly in many countries. Masks and social distancing do reduce risk. Although most Western countries told you otherwise to begin with on masks. And told you incorrectly how to wash hands, and also incorrectly said it reduces risk (considered unlikely). I'll add being outdoors also probably reduces risk, not sure this is commonly touted yet.
  - raziel2p 6y ago
    I mean risk at the societal level, not individual. Maybe there's a better word. Anyway what I mean is that the risk of the virus/disease spreading faster than our healthcare systems can handle is lowered by effective contact tracing. Not that I personally am less at risk of being infected if I install the app.
    - aaron695 6y ago
      Ok, some politicians etc were calling the apps a condom or sunscreen. All evidence since March has been boots on the ground for contact tracing is what's important. Not tech. But the Bluetooth apps, which we know can't work well also don't try for behaviour change, they might even increase risk. This app at this college is trying for positive behaviour change.