TraceTogether – behind the scenes look at its development process

Singapore has been battling COVID-19 since its 1st case of infection was confirmed on twenty-three Jan 2020. As of twenty-three March, 12pm, there are a complete of 509 confirmed cases in Singapore. the abundance of the credit for the country’s response goes to our contact tracing efforts. operating together with aid colleagues at the hospitals, yet because the Singapore personnel, the contact tracers at the Ministry of Health (MOH) got to date known over eight,000 shut contacts UN agency are segregated.

While contact tracing has helped Singapore contain the unfold of the virus, the method is conscientious and effortful. what is more, even the foremost strenuous efforts of contact tracers will be discomfited by lapses in memory and therefore the incontrovertible fact that there’s merely no method for folks to retroactively determine strangers they may have acquired contact with?

But most of the people already carry a pocket contact tracer with them the least bit times: their mobile phones. Taking advantage of Singapore’s high mobile penetration rates, GovTech has engineered TraceTogether, associate degree app that uses Bluetooth to try and do contact tracing with a distinction.

Who, not where

Given the ubiquitousness of mobile phones and their vary of communication capabilities, they were a natural start line once puzzling over technological solutions to the matter of contact tracing. However, several of the prevailing apps target location-based services, mistreatment international positioning service (GPS) to spot people that are in shut proximity to associate degree, infected persons.

While GPS works well in wide, open areas, it fares poorly once it involves indoor and extremely urbanized settings, said Mr. Jason Bay, Senior Director of state Digital Services at GovTech. “If you’re one floor down in an exceedingly building, your GPS location may look constant as somebody within the floor on top of you thanks to signal reflections and multipath propagation effects,” he explained.

Aside from the technical challenge, mistreatment location knowledge for contact tracing additionally raises serious privacy and knowledge security issues. If users are hesitant to transfer the app for worry of unknowingly revealing their movements, its ability to link the dots would be greatly diminished.

“So rather than trying to tackle the difficulty of contact tracing by respondent the question of ‘where,’ we have a tendency to address contact tracing by respondent the question of ‘who’,” explained adult male. Bay, UN agency diode the team behind TraceTogether. “After all, you’ll argue that the virus doesn’t care wherever transmission happens; it’s solely fascinated by whether or not there’s a hospitable host in shut contact.”

He supplementary that TraceTogether solely wants Location Permissions to grasp the relative distance between users and therefore the app doesn’t collect or use any real-world geographic location.

Much more than memes

Used by teens to bringing random footage of memes to strangers, Bluetooth also can be placed to use within the service of contact tracing. rather than acculturation, phones with the TraceTogether app put in can send one another a message that contains four items of information: a timestamp, Bluetooth signal strength, the phone’s model, and a brief symbol or device nickname.

If somebody with TraceTogether is diagnosed with COVID-19, he or she will merely transfer their knowledge to MOH, able to} then be able to decipher the knowledge and start contacting alternative TraceTogether users UN agency are in shut contact of the confirmed COVID-19 case.

“Bluetooth encompasses a most vary on the order of regarding 10 meters,” Mr. Bay said. “And as a result of it’s an occasional power signal that degrades terribly quickly over distance, we are able to use signal strength to work out space between 2 phones inside an inexpensive margin of error.”

And currently for one thing fully totally different
This ‘figuring out’ clad to be far more difficult than anticipated, however. “In the course of developing this app, we have a tendency to acknowledged that the Bluetooth signal strength distinction between 2 phones will be one,000 p.c or maybe more—up to ten,000 p.c even,” Mr. Bay said.

“To use a trope, some folks speak with booming voices et al. have terribly soft voices. If you’re attempting to estimate the space supported volume, you may get to calibrate the mike you employ for every speaker – loud or soft. one amongst the toughest elements of this project was characterizing and calibrating across totally different models of phones,” he said.

The team completes up testing dozens of various models, an achievement the assistance of partners at Nanyang tech and therefore the Institute for Infocomm analysis UN agency had nonresonant chambers that blocked out all alternative signals so they might live base-level signal strength. All this was new territory for the GovTech engineers, UN agency ar primarily software package instead of hardware engineers.

“Compared to the opposite apps and websites we’ve got done, TraceTogether is qualitatively and unconditionally {different|totally different|completely different} as a result of we have a tendency to had to drill deep into the Bluetooth hardware stack and access low-level practicality that was typically enforced otherwise across different Bluetooth chipsets,” Mr. Bay said. “Many teammates shared that this was one amongst the foremost fulfilling comes for them thanks to the number of learning required.”

The end result’s associate degree app that may hopefully be able to facilitate contact tracers uncover antecedently unknown shut contact with COVID-19 cases and speed up the contact tracing method, he ended.

“TraceTogether doesn’t replace the contact tracing method. Instead, we have a tendency to see it as a very important tool within the tool cabinet of contact tracers. it’s not sufficient to have confidence technology alone, as we’d like the experience publicly health and communicable diseases to form a sense of the information collected mistreatment this technology,” added Mr. Sutowo, MOH’s Director of Analytics and Knowledge Management. “TraceTogether solely works between phones that have the app downloaded and running. The additional folks transfer and use TraceTogether, the simpler it’ll be. we have a tendency to hope additional folks can use it.” he added.

Download APK