Use Bluetooth for nearby device detection

[jnebrera]

Hi there,

I really like your project.

One point though, in this article I'm showing the advantage of using Bluetooth based nearby detection in order to flag people that needs to undergo testing.

I would suggest you to use the ideas shown in the article to improve the software

Thank you

http://tiny.cc/o8l3lz

[eladnts55]

Thanks for your contribution!
We want to add Bluetooth too.
We will try to use the same code like https://github.com/covid19cz

Have a nice day!

[juanjo-ramos]

I might be able to help with this one. I did a tiny POC on this just to play around with the BT stack on iOS https://github.com/juanjo-ramos/CovidApp-iOS. I know this project is built with Ionic though 🙂

How are you guys tracking the future improvements? Is there a public JIRA / Trello, etc. board available? Thanks.

[antonioparraga]

Hi! We are almost done with the BT LE, but we’ll appreciate if you could do a code review once we submit our code. We have review your implementation and we think we are doing more like the same. We are scanning via BT LE between X seconds, and at the same time we are sending advertisements via service UUID (we’re generating unique UUID for each user), and it seems like you are doing a really similar thing, right? So, we’ll appreciate if you could take a look at the code once we commit our solution. Thank you! Antonio

…

On 4 Apr 2020, at 19:49, Juanjo Ramos ***@***.***> wrote: I might be able to help with this one. I did a tiny POC on this just to play around with the BT stack on iOS https://github.com/juanjo-ramos/CovidApp-iOS <https://github.com/juanjo-ramos/CovidApp-iOS>. I know this project is built with Ionic though 🙂 How are you guys tracking the future improvements? Is there a public JIRA / Trello, etc. board available? Thanks. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#42 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAJ6JYAMLJLMWDH2EKFNAILRK5XLNANCNFSM4L2SMLWA>.

[juanjo-ramos]

That was fast 🙂. Great work 👏
I'll keep a look at open PRs but do you mind tagging me on it anyway? I'm not an Ionic expert but I should be able to grab the main concept.

What you describe is pretty accurate. A couple of comments:

• My idea was that devices would include the userId currently logged in in the advertisement payload. You're probably doing that already!
• On iOS at least you also have the RSSI (received signal strength indicator). That is important because you're only interest in the peripherals with a strong signals since the device might be seeing other BT devices that haver 20m away that shouldn't count as a contact.

Anyway, please tag me in the PR. I'll be happy to review it. And if there are any improvements to be done afterwards, happy to help there too!

[antonioparraga]

Hi! I think this is exactly how we have done the implementation, in 1 hour we’re going to upload our changes. Thank you!

…

El 4 abr 2020, a las 20:28, Juanjo Ramos ***@***.***> escribió:  That was fast 🙂. Great work 👏 I'll keep a look at open PRs but do you mind tagging me on it anyway? I'm not an Ionic expert but I should be able to grab the main concept. What you describe is pretty accurate. A couple of comments: My idea was that devices would include the userId currently logged in in the advertisement payload. You're probably doing that already! On iOS at least you also have the RSSI (received signal strength indicator). That is important because you're only interest in the peripherals with a strong signals since the device might be seeing other BT devices that haver 20m away that shouldn't count as a contact. Anyway, please tag me in the PR. I'll be happy to review it. And if there are any improvements to be done afterwards, happy to help there too! — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.

[martejpad]

Hello!!

First of all congrats on your project, you've done such a great job!! 💪

I was wondering, what happens when the app goes in background or suspended mode? Is the app able to do Bluetooth scans and therefore detect other devices? I would imagine Apple specially would restrict this quite a lot.

I came across @juanjo-ramos Youtube demo and in the video you can see that the counter is not updated until the app on the second phone is in the foreground.

Many thanks in advance!

[antonioparraga]

Hi,

So, the app has a different behaviour in foreground and in background. Whenever the apps goes to background you can check at

open-coronavirus/app-citizen/src/app/shared/services/tracking/bluetooth-tracking.service.ts

Line 98 in 7058c56

protected prepareBackgroundMode() {

is a method that changes the way the app works in order to save lot of battery.

In the other hand, we also use the background fetch in order to restart the scanning (look at https://github.com/open-coronavirus/open-coronavirus/blob/master/app-citizen/src/app/shared/services/background-fetch.service.ts line 23), which forces again to perform a full scan for new devices. It takes no longer than 30 secs but is another way to detect devices. As soon as background fetch happens every 15 minutes (is not as exact as 15 minutes, but it depends on many factors but a kind of().
The think is that in our tests apps in background interchanges their keys, but it takes long than in foreground, but it happens within a 15 minutes window, which is enough according to the ECDC recommendations.

[antonioparraga]

btw, where is the YouTube video you are talking about?