OK, I hadn't thought this all the way through when I first posted, but now I think I"ve got my head wrapped around it despite the almost incomprehensible (to me, anyhow) tech jargon in your linked doc.

For the benefit of all, this is how I THINK it works (totally simplistically, obviously). Please correct me if I go wrong.
  • If you and I pass in the street and we're both opted in, our cell phones exchange untraceable "tokens."
  • If one of us is positive, I assume that the other will somehow be notified, but how and when isn't spelled out.
  • If neither of us is positive, both our tokens go into a database somewhere, and if one of us shows symptoms within 10 days the other is notified of exposure.
Does that sound correct?

If that's the way it works, failure to opt in and asymptomatic carriers will, as has been previously noted, be major shortcomings, but what bothers me more is
Originally Posted By: joemike's linked doc for which I can't figure out how to post a URL
The Contact Detection Service is the vehicle for implementing contact tracing and uses the Bluetooth LE (Low Energy) for proximity detection of nearby smartphones, and for the data exchange mechanism.

Since, as far as I can tell, minimum Bluetooth range is 10 meters/33 feet, which far exceeds social distancing guidelines, the system appears to be subject to a plethora of false contacts which could ultimately lead to a large number of false positive notifications going out when the guy with whom you "had contact" but was really across the street shows symptoms.

Or can Bluetooth range be modulated for the app?


The new Great Equalizer is the SEND button.

In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire