Bluetooth is a wireless technology which uses short-wavelength radio waves to facilitate the building of personal area network (i.e., interconnectivity among electronic devices within one’s workplace) or exchanges of data between mobile devices in close proximity. The first consumer Bluetooth was made available in year 1999 and it has turned ubiquitous over the years. Recently, the ongoing Covid-19 pandemic is bringing the technology under the limelight again.

Can Bluetooth be trusted?

Apple and Google jointly developed a tracking software that aims at informing users if they have been in touch with anyone infected with coronavirus and if they will be at risk of becoming ill. The application is believed to be ready in iPhone and Android devices by May 2020. It runs on the notion that since Bluetooth continuously scans for neighboring devices, somebody who had received a positive diagnosis may inform the app and subsequently, the wireless signal can alert those who are nearby.

However, it remains unclear how close and how long one needs to be with a virus carrier to be infected. Thus, it may be challenging for Bluetooth to uphold such an important task. Indeed, Bluetooth is easily disrupted by everyday objects like walls, pockets, and human bodies. It’s also rather susceptible to false positive. For examples, users living in apartments separated by walls may receive an alert reminding them that they are near to each other.

On the other hand, users may be standing back to back from each other but because their bodies had blocked a substantial amount of signals, Bluetooth may misinterpret how far these users are apart and fail to send an alert. These potential sources of error are not unique to Bluetooth but all contact-tracing apps. Experts believe they can be overcome by utilizing more data to teach the machines how to appropriately understand various signals.

Improving accuracy of contact tracing apps

Data coming from a mobile’s ambient light sensor tells whether there are potential blockages while information coming from the device’s compass can provide better orientations. A research team from the Massachusetts Institute of Technology (MIT) had conducted a study to examine how venues, outdoor/indoor indicators, positioning of phones and presence of other devices may affect signals.

The team asserted knowing these variabilities helps to make sense of signals and it’s most recommended to use a combination of different tools to increase our confidence towards contact tracing technology. Although it’s not a silver bullet, Bluetooth remains popular because it’s a low-power signal that’s can be found in most mobile devices. It comes with Received Signal Strength Indicator (RSSI) that’s capable of detecting the strength of signal from another phone (i.e., the stronger the signal; the closer the proximity and vice versa).

This quality alone complements the kind of manual contact tracing (i.e., asking individuals where they have been and who have they been in contact with) that epidemiologists have been performing in the past decades. The pandemic has given many old and new technologies a platform to showcase their respective efficacy but only time can tell whether they are truly effective in minimizing casualties and shortening lockdowns.


Author Bio

Hazel Tang A science writer with data background and an interest in the current affair, culture, and arts; a no-med from an (almost) all-med family. Follow on Twitter.