Corona Tracer®: Preventing expansionof workplace clusters
Jun Matsumura

Representative Director
CTO, IoT-EX Inc.

1. Introduction

The SARS-CoV-2 coronavirus that causes COVID-19 isreported to be spread mainly through contact with infected air
droplets, and the spread can be controlled effectively by severing
the paths of such infection. Formation of clusters can be prevented
by “contact tracing,” which involves quickly identifying any close
contacts and notifying them when an infected person is found.
Conventionally, contact tracing has been done mainly bytelephone, asking questions, checking and giving instructions.
This method takes time and effort to identify patients andbecomes more difficult as the number of patients increases. With
the recent spread of smartphones, efforts to accelerate contact
tracing using mobile applications have begun.
In South Korea, a mobile application was developed using
the location services smartphone feature (a standard feature that
integrates data from GPS, base station locations, Wi-Fi, thecompass, etc.), which linked with several systems that collectpersonal information to track the movement history of infectedpeople. Currently published information includes age, sex,workplace, approximate home address, convenience stores used,and modes of transport used. Names are not published, but
associates in the same cluster are, and there have been reports
of individuals being identified through SNS and attacked. Suchincidents have been used to show the difficulty of maintaining
privacy while dealing with infection risk.
Another mobile application called “Trace Together” wasdeveloped in Singapore using a short-distance communication
technology called Bluetooth Low Energy (BLE). The application
enables rapid contact tracing and notifications by keeping a 21day log of people who were in close proximity and also had theapplication installed on their smartphones. This application uses
the phone number for notifications, so it is considered to use
individual-identifying information.
Since late March, 2020, our group and several others in Japan(such as Code for Japan) have also developed contact tracing
applications. At the time, “Trace Together” in Singapore had
about a 10% usage rate, was initially only available for Android
devices, and had to be run in the foreground. Apple severely limits
background applications over concern for privacy and battery life,so dealing with these restrictions caused difficulty in Japan, whereiPhones have a large market share.
Amid these efforts, on April 10, 2020, Apple and Google
jointly announced their support for government and insurance
agency efforts to prevent the spread of infection, including acontact tracing framework that uses Bluetooth Low Energy (BLE)and not location services features. This enabled iOS devices,not only Android devices, to also have applications that run
continuously in the background.

2. Issues identified during development andresolutions

We initially analyzed conventional contact tracing methodsusing telephones and identified the following five necessary
tasks: (1) Collection of contact information, (2) Storage ofcontact information, (3) Reporting from infected persons, (4)Identification of close contacts, and (5) Notification of closelycontacted persons. We then studied how these could beimplemented and determined the scope of manual work that could
be systematized effectively.
We first conducted tests to verify collection of contact
information using BLE, which indicated that there was muchnoise and attenuation due to pillars, walls, clothing, and people’sbodies, so that it was not possible to estimate distances (such as“within 1.5 m”) from the strength of signals. Thus, we determinedthat if the signal was relatively strong, those persons would beconsidered under close contact.
We then decided that contact information would be stored in
the application. Mobile applications use a sandbox architecture,so that a third-party application cannot see data stored in anotherapplication. Only identification numbers, which cannot beassociated with an individual, would be sent to the cloud. If alldata were sent to the cloud immediately, real-time monitoring
would be possible. Even if data from a given application isprocessed to not identify individuals, the data could be linked
with information collected by other applications from the samedeveloper on the same smart phone, enabling them to identify
individuals. How to handle the risk of identifying individuals
when linking to the cloud was a concern when developing aservice.
Apple and Google published a mechanism for contact
tracing with sample code and specified that it would support
one application per country. This mechanism was then built
into the OS itself, so that the logic for collecting and storing
contact information could not be changed. The mechanism has anExposure Notification function to indicate when the user has been
exposed to risk of infection.
From the start, our group has intended to provide a contact
tracing service for corporate administration (general affairs
administrators in most cases) rather than for national or insurance
agencies. Enterprises must take measures to prevent the spread ofNew Breeze Summer 2021

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■ Figure 1: Typical operations for administrators when an infected person contacts the company

infection as part of their labor health and safety efforts to begin
with, and our solution is meaningful as part of such efforts, andchecking contacts using our service can be a meaningful part ofsuch efforts for companies required to do so. It could also be used
to meet the needs of national and regional public organization as ameasure against the spread of infection.
Enterprise managers (general affairs administrators in mostcases) manage employee names and contacts as part of their workand use them as needed. We separated the system for collecting
and storing contact information from the system for identifying
close contacts and coupled them loosely to prevent real-timemonitoring and to forbid access to contact information unless aninfection occurs.
We also do not enter information related to infection into thesystem, but rather, an (infected) person’s name and (incubation)
period is specified, and a list of employees who might have had
close contact is displayed.
We have also prohibited linking of data stored in the systemwith any other system. This was made possible technically byusing IoT-HUB, which we developed in collaboration with theUniversity of Tokyo, Institute of Industrial Science, IoT Special
Research Committee. Since IoT-EX Co. Ltd. is a registered
telecommunications operator, which is regulated by thegovernment, we are also prohibited from monitoring data on the16

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cloud and must protect data privacy and security.
Enterprises are also using feature phones instead ofsmartphones in some cases. There is also the issue of handling
visitors in addition to employees. To deal with such situations,
we also added support for beacon tags and QR codes. With
these additions, we also separated BLE operation for central andperipheral devices. Using beacon tag technology, it is also possible
to handle children and the elderly, and with QR codes, we canalso support schemes that have been used with feature phones, inwhich contacts are registered by reading a QR code and sending
an empty email message. This technology also enables us to
support situations such as event spaces.
In the process of testing various beacon tags, we found thatspecifications for beacon tags are not uniform, and there areinteroperation issues between different near-contact tracking
systems (collecting and storing contact information). This can also
be handled using IoT-HUB and applicable drivers. Specifically, byusing a driver and a particular parsing feature of the IoT-HUB,
no change to the application is required, and the devices can besupported right away, by just creating a format definition file forparsing (taking approximately 10 min.).
QR codes have also been adopted throughout Japan in recentyears, but the mechanisms used are not consistent in each region,
and we found out that there is no interoperability among them.

■ Figure 2: Overview of the Corona Tracer system■ Figure 3: Operation with Corona Tracer

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This can also be handled using IoT-HUB and drivers.
We also had requests to be able to check work attendance rates
from companies using Corona Tracer, so we added the ability to
do so from the contact information collection and storage system.
The system provides attendance rates by department and for thewhole company, and by adding a sensor data (PM2.5 and CO2levels) collection and storage system, we are able to determine
whether the “Three C’s” (avoidance of closed space, crowded
places and close contact) are being handled or not.
Recently, facilities are being required to operate safetymeasures for visitors in spaces where many people gather andinteract. We tested whether Corona Tracer would be effective insuch cases, and found that with multiple central devices, a roughestimate of locations of people could be determined from the BLEbase stations. This showed that we would be able to trace possible
transmission by air droplets (person-to-person), as well as throughcontact with objects that other people had touched (person-toobject-to-person). We are continuing to test this measurement.

3. Conclusion

The “COCOA” contact checking application for Japan,
which notifies people if they may have had close contact withsomeone infected with the COVID-19, was reported to have been
downloaded 18.9 million times as of the morning of October 26,
2020, which is approximately 15% of the population. We are being
required to put a new type of lifestyle into practice in our daily
lives, to protect ourselves, our families, the people around us, ourworkplaces, and our region from the spread of infection.
Our group has focused particularly on the workplace,
supporting new work styles, and we aim to provide a service thatwill be useful for enterprise administrators. There have beena variety of services offered for business continuity planning(BCP) for situations such as major earthquakes or a pandemic.
We are offering “Corona Tracer®” to contribute to stopping theexpansion of workplace clusters in enterprises. Most of the features
introduced in this article are patented or patent pending.
References
・ Privacy-Preserving Contact Tracing
https://covid19.apple.com/contacttracing
・ Exposure Notifications Frequently Asked Questions	https://covid19-static.cdn-apple.com/applications/covid19/current/static/contact-tracing/
pdf/ExposureNotification-FAQv1.2.pdf
・ Ministry of Health, Labour and Welfare, “Novel Coronavirus Q&A (For Enterprise)”	https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/kenkou_iryou/dengue_fever_qa_00007.
html#Q6-1
・ Examples showing the need for a contact checking application in society.
https://www.nikkei.com/article/DGXMZO60262830R10C20A6MM8000/
・ Accelerate identification of cases and close contacts with Corona Tracer
https://smartiot-forum.jp/iot-val-team/iot-case/case-iot-ex
・ Planning, Development and Launch of Contact Tracing Service in Six Weeks—IoT-EX
Implementation	https://smartiot-forum.jp/iot-val-team/iot-case/mailmagazine/mailmaga-03920200514?mailmaga=・ Contact Tracing Scheme to prevent the spread of COVID-19
https://webtan.impress.co.jp/u/2020/08/25/37244
・ How Apple and Google Are Enabling Covid-19 Contact-Tracing
https://www.wired.com/story/apple-google-bluetooth-contact-tracing-covid-19/
・ Apple and Google partner on COVID-19 contact tracing technology	https://www.apple.com/ca/newsroom/2020/04/apple-and-google-partner-on-covid-19contact-tracing-technology/
・ Why Singapore’s COVID-19 contact tracing application cannot be used in Japan as-is”
https://xtech.nikkei.com/atcl/nxt/column/18/01279/041700002/

Cover Art
Masaki Inari Shrine and Sumida River Ferry fromthe series Famous Places in the Eastern Capital(Tôto meisho)
Utagawa Hiroshige (1797~1858)

Collection of the Art Research Center (ARC)
Ritsumeikan University
Object number: BN03828992-1-12-1

18New Breeze Summer 2021