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At the beginning of February, a tight-knit surveillance system appeared in the skies above Taiwan to track the locations of people at high risk of contracting the new coronavirus disease (COVID-19) or who are required to quarantine themselves at home.

To date, more than 11,000 mobile phone numbers have been monitored by this epidemic prevention platform, which can only be seen by Taiwan’s Centers for Disease Control (CDC) and entities that have received CDC authorization. The locations of the phones’ owners appear in city and county heat maps and real-time location maps.

The platform is founded on what the government calls “epidemic prevention mobile phones” – distributed to people in home-quarantine being monitored, police stations and local government agencies. Individuals in home-quarantine can also agree to be monitored through their own mobile phones rather than one assigned by the government.

What the platform does is connect all of these phones together with the CDC’s own platform, so that when a person ordered to remain in isolation at home goes out, the authorities will immediately be notified by text message on their special phones.

Cellphone Tracking + Electronic Fence Warnings

That technology attracted attention from faraway nations.

When Israeli Prime Minister Benjamin Netanyahu addressed the coronavirus threat to his country at a press conference on March 14, he said, “We are at war with an invisible enemy.” Because of that, he said, Israel would use invasive digital monitoring measures, which turned out to be cellphone tracking, to track sick individuals and the people they came in contact with, according to a Times of Israel report.

The technology, he said, “was tested in Taiwan, apparently with great success.”

Photo by Hannah Chang/CW

Li Cheng-wei, senior director of Chunghwa Telecom’s Big Data Department, said the tracking technology referred to by Netanyahu is the electronic epidemic prevention platform being used by Taiwan, which incorporates cellphone location tracking and an “electronic fence” system.

The deputy chief of the National Communications Commission’s Department of Infrastructure and Cyber Security, Bruce Cheng, confirmed to CommonWealth that Chunghwa Telecom developed the platform during the Lunar New Year holiday in late January to help the CDC deal with the coronavirus emergency. Linking together the signals of the base stations of Taiwan’s five major telecom operators, it can directly monitor the mobile phone locations of all those required to remain quarantined at home.

Li explained that the platform can display the current position of people being monitored and their movements in the previous 24 hours, enabling the CDC and police to track them in real time. If they are later confirmed to have COVID-19, the system can pump out a record of the individual’s previous movements, helping expand the search for people with whom that person may have come in contact.

Tracking through Triangulation

The positioning system, according to one telecom insider, can immediately identify an individual’s location by triangulating the person’s mobile phone with base station signals.

Once a SIM card has been inserted in a mobile phone, the device searches several surrounding base stations and selects the closest one with the strongest signal. The phone’s location can be determined by the distances between three base stations and the mobile phone, or triangulation.

“As long as a mobile phone is turned on, it remains connected with the base station and maintains contact with the network’s signal, so whether the user is making a call or not, the base station will know the user’s position,” said Lin Kuo-fen, Chunghwa Telecom’s chief technology officer, explaining the concept of localization in cellular networks.

At the same time, the telecom insider said, all past records of mobile phone signal connections to base stations, after being “de-identified” (to prevent personal identities from being revealed), can be stored within a certain timeframe in the backend of each telecom company’s system. Thus, a list of places where a COVID-19 patient may have been can be accessed relatively easily.

The idea behind “electronic fencing” is to designate the range of base stations where the mobile phone of a home-quarantined individual can appear, and if it moves out of that range, the police and the CDC will be automatically notified by a base station.

When Chunghwa Telecom’s people gathered on the second day of the lunar new year (January 26) to help build this epidemic prevention platform, its first step was to determine and set the numbers of the “epidemic prevention phones” distributed for use with the platform to people being monitored and local authorities, said Chunghwa Telecom’s Li. It then expanded the system to accept the phone numbers of devices owned by people being quarantined, giving those in isolation the choice of being monitored electronically by a phone assigned by the government or their own mobile phone.

Once the tracking system’s interface with these functions was completed, it was handed over to the CDC.

Photo by Kuo-Tai Liu/CW

Now, when CDC staffers log into the system, they see a heat map of Taiwan on their screens showing the number of people infected with coronavirus infections in each district of every city and county as well as the number quarantined at home.

A click reveals the latest position of a person being monitored, and CDC staff can also check basic information about the individual and the person’s locations and movements in the previous 24 hours.

The CDC provides the mobile phone numbers of all those in home-quarantine or home-isolation to the five major telecom companies to be entered into their systems. These telecom operators then upload the location history of the phones of the people being monitored every 10 minutes to the epidemic prevention platform.

At present, the platform is monitoring 2,400 “epidemic prevention mobile phones” and another 4,000-plus people isolated or quarantined at home who have accepted monitoring through their own phones.

Retroactive Tracking

The telecom industry insider said that the CDC requested the NCC – Taiwan’s broadcasting and telecommunications regulator – to enlist the cooperation of telecom operators in finding the locations and histories of specific mobile phones based on the Communicable Disease Control Act.

This proved helpful when Taiwan scrambled to track the whereabouts of Diamond Princess passengers who disembarked during a 10-hour stop in Keelung in northern Taiwan on January 31 before the cruise ship headed on to Yokohoma, where it was quarantined for over a month and became a breeding ground for the coronavirus.

The CDC was able to track passengers’ side trips to Jinguashih, Keelung and Jiufen because the NCC asked Chunghwa Telecom to analyze where the passengers went after getting off the cruise line based on the relative positions of their mobile phones and base station signals.

Li said there were dozens of base stations around the port of Keelung at the time, and Chunghwa Telecom used big data to find and track the movements of the 1,700 people who scattered around the area during the cruise liner’s stop there.

“We used algorithms to differentiate the people connected to each base station and screened different identities to isolate roaming customers from the Diamond Princess. Then we found the digital footprints of the phones’ roaming numbers.”

The epidemic prevention platform now has the capacity to monitor more than 100,000 people if necessary and will be able to incorporate all overseas visitors in the future.

Invasion of Privacy? NCC Says It’s Legal.

In the past, base station triangulation was primarily used to catch criminals or help with a major disaster or a hiker going missing in the mountains, a police officer told CommonWealth. Different laws were invoked to cover each situation. For emergency rescues, for example, the Disaster Prevention and Protection Act or Mental Health Act might be invoked to justify requests for call records to find a missing person.

For suspected crimes that could endanger national security or economic or social order, police agencies have been able to petition a court or the heads of intelligence agencies have been able to apply to issue an interception warrant based on the Communication Security and Surveillance Act to monitor a suspect’s communications. In such cases, telecom operators will help pull relevant information from their systems.

“In the past, it was security agencies, based on specific procedures, asking telecom companies to help provide real-time location information,” the police officer said. Today, amid the global pandemic, that process has been simplified to create a more direct monitoring mechanism.

But that has raised invasion of privacy issues. In fact, when Netanyahu announced that Israel would imitate Taiwan and use digital monitoring technology to know who came in contact with people infected with the virus, he acknowledged that the technology relied on “a certain invasion of the privacy of those people.”

“Up until today, I avoided using these measures in the civilian population, but there is no choice," he said.

Acting NCC chief Chen Yaw-shyang argued, however, that this is not an issue in Taiwan. He said the current measures do not constitute invasions of privacy based on the Communicable Disease Control Act and Article 16 of the Personal Data Protection Act, which allow the reasonable use and restriction of personal information in times such as epidemics.

A senior executive at a Taiwanese telecom company said the company has generally not sought out the locations of specific individuals because of privacy and personal information protection concerns, but agreed to build a special system with the authorization of the CDC and NCC because of the present circumstances.

Beyond the epidemic prevention platform, the CDC has also partnered with DeepQ, a healthcare division of HTC, and instant messenger service Line on a Line account “@taiwancdc” or “疾管家” (literally “disease manager”) that has been downloaded more than two million times.

The CDC is expanding this Line bot function to enable Line users being monitored or under quarantine to report their health conditions to the chatbot to share work burden from front-line workers.

The move’s potential impact is not without its skeptics, including a telecom company technician. “Will people really tell the truth to a chatbot?

The function does have the benefit, however, of having the users being monitored voluntarily provide accurate location information.

A technician in the law enforcement field said that determining locations through base stations in Taiwan can have margins of error ranging from hundreds of meters to several kilometers. If apps are used in the future that get people to agree to GPS positioning, the combination of base station positioning, GPS, and dual-frequency

GPS will more accurately pinpoint people’s locations, the source said.

As the epidemic worsens by the day in Europe and the United States, leading to rapidly rising numbers of imported COVID-19 cases in Taiwan, more people will be required to isolate themselves. Should the situation become dire, the next step the CDC may take in the technological battle against the highly contagious disease is to require residents to allow a mobile phone app to track their whereabouts.

Even with the potential privacy issues of doing so, it would not come as a surprise, considering the stakes and the havoc already created by COVID-19 around the world.

Have you read?

♦ How to beat the coronavirus without the WHO? Ask Taiwan

♦ Civic Tech Versus COVID-19: Online Map and Reservation System Help Fight the Virus

♦ Where is Globalization Headed Amid COVID-19 Epidemic?

Translated by Luke Sabatier

Edited by TC Lin

Uploaded by Sharon Tseng