Exposure Notifications: Use Bluetooth on your smartphone to be notified of COVID-19 exposure

In the early months of the COVID-19 pandemic, we saw a rare tech company collaboration emerge. Apple and Google partnered to define an Exposure Notification protocol that could be implemented on the devices we carry around in our pockets every day. Released in May, the protocol uses existing Bluetooth technology inside our devices to allow users to opt in to notifications for possible COVID-19 exposure. It relies on our devices to anonymously communicate with one another in order to establish a network of users that one has come into close proximity with over time.

How do Exposure Notifications work?

Apple and Google collaborated on defining a protocol that allows iPhone and Android devices to interface with one another for contact tracing purposes. As designed, if users have the service enabled, when you happen to be near someone who is later diagnosed with COVID-19, you can get a notification on your device indicating potential exposure. Your smartphone generates a set of rotating keys that are exchanged with other smartphones nearby. Each device maintains a list of keys from other devices that it was near. When a user is diagnosed with COVID-19, they can choose to report it. The system then anonymously notifies other devices that have been nearby the affected user's device. It’s not a fool proof way of explicitly identifying where you have come into contact with COVID-19, but rather a way to be notified that you may have been exposed. Obviously, the more people in your daily interactions that opt in to the service, the better the system could be at potentially identifying your exposure.

The technology leverages the Bluetooth Low Energy (BLE) already built into nearly all of the smartphone devices we carry around. BLE provides a wireless communications protocol usually used over short distances between connected devices. It’s also used as a beaconing protocol since low power devices can be built to broadcast on BLE without consuming much power. This is also why it is possible for your smartphone to be both listening for BLE devices and broadcasting via BLE without having much impact on your battery life. There are several applications of the technology that our devices use today, so it is likely that you are already using BLE on your device even though you may not be aware.

The Exposure Notifications service is enabled by public health authorities across the country and around the globe. In order to enable to service, health departments at the state or local level in the United States implement the services consumed by the devices to share the anonymous keys amongst devices. Both Google and Apple have provided a set of APIs that app developers can use to build an app for a health authority to interact with the Exposure Notification system. Custom applications can allow users to opt in and also provide a custom interface for providing positive COVID-19 test results that are tied to the health authority testing and tracking systems. For iOS, users don’t necessarily have to download a 3rd party app to participate, but rather enable to service on their device once implemented by a local health authority.

Here's a great short video from Google about Exposure Notifications:

How do I start using Exposure Notifications in Wisconsin?

Here in Wisconsin, Governor Evers and the State Department of Health have indicated that Exposure Notifications will be available on Wednesday, the 23rd of December.

Users of the Apple iPhone do not need to download another app, they can simply enable Exposure Notifications if they choose to opt in. The feature was launched with iOS 14 and has been incorporated into the latest update for iOS 13 as well.

On Android, a new app called WI Exposure Notifications will be launched on the 23rd. Android users can download and install the app on their device to opt in and turn on the service.

It’s expected that iOS and Android users will get a notification about the service being available after it has gone live this week. Notifications from Google or Apple should include instructions on how to enable the service on each device.

How many people will opt in to Exposure Notifications in Wisconsin?

It’s difficult to tell how many people will choose to opt in to the system. Over the summer, several states launched Exposure Notifications and found difficulty getting traction with users. However, more recently, adoption rates in some areas have significantly improved with the incorporation of the service right into the operating system like Apple has done. It was reported that Maryland was able to enroll about 25% of the adult population into the system in a recent roll out this fall. That is a significant adoption rate for any app or service like this in a very short time, but clearly the system depends on pretty widespread adoption across the population to be effective. We will have to wait and see how many Badgers decide to opt in.

So what?

It remains unclear how effective this technology driven approach will be in the effort to contact trace exposure to COVID-19. It may be another tool that individuals can use to have knowledge about potential exposure to make more informed decisions.

When the current pandemic recedes, it will also be interesting to see how this technology can be used going forward. If there is enough adoption as a part of this cycle, it may actually prove to be useful for other types of exposure notification going forward.

It’s encouraging to see collaboration across tech companies on initiatives like this and perhaps we will continue to see more in those regards.

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