Digital Contact Tracing for Safely Returning to Work

Apoorva Kiran
Illustration: © IoT For All

As businesses and schools reopen amidst the ongoing COVID-19 pandemic, we need to ensure the safety of returning employees, customers, students, etc. Businesses and schools have implemented a combination of prevention and intervention plans. The prevention plan consists of enforcing the use of masks, social distancing, and deep sanitization. The intervention plan consists of the use of manual contact tracing by safety officers and the human resource team.

Unfortunately, just masks, social distancing, sanitization, and manual contact tracing are not sufficient for a safe return to work. At many workplaces, it’s difficult to follow social distancing etiquette because of the nature of the work. The fourth line of defense, which is the most important among all, contact tracing is unfortunately prone to human error and limitations on human memory, which makes it difficult to manage the spread of COVID-19 in case of an infection. Here we present an overview of several IoT based digital PPE (Personal Protective Equipment) that encourage social distancing and contact tracing more reliable.

Why Digital PPE?

The Coronavirus pandemic grew from a handful of cases to more than a million in a matter of months. One of the reasons the spread of the disease has taken so long to get under control is that the virus is infectious to an extent that even the slightest amount of human error can result in massive spread.

One recent survey, conducted by Data studio, found that as many as 40% of people leave home to attend their jobs, and among those, as many as 31% don’t wear masks all the time because they find them uncomfortable or forget pandemic social etiquettes. Similarly, 38% of people are not following social distancing etiquettes, one of the prime reasons 20% of workplaces are not able to enforce or support social distancing practice.

Between health professional recommendations and several survey assessments, it’s not a surprise that masks, sanitation, and conventional contact tracing are insufficient for a safe return to work. This is why the use of digital PPE is important.

Digital PPE involves the use of highly precise network protocols to give social distancing alerts to people, provide etiquette reminders, and facilitate accurate and error-free contact tracing. The technology ensures safety at a large scale and gives a comprehensive safety net for keeping COVID infection spread at bay.

Both false positives and false negatives have serious issues. False-positive results cause undue stress–imagine if one falsely diagnoses or predicts that you might have COVID! Besides that, every false positive can potentially cause an employer a direct loss of 15 days x$100/day= $1500. If you add the cost of hiring the replacement for a COVID suspect and other administrative costs, the overall cost of a false positive is more than $5000.

False-negative results can be even more disastrous. If your safety manager isn’t able to trace the COVID positive person sooner rather than later, it can result in months-long shutting down of plants, and potentially a massive lawsuit. Digital PPE provides much needed security amid an ongoing pandemic.

Digital Contact Tracing

IoT technology is an excellent way to digitize and supplement the conventional contact tracing process. There are two different kinds of IoT solutions when it comes to contact tracing: BLE based and Ultra Wideband based.


The BLE based method uses BLE protocols to determine the relative locations of two beacons. These beacons can be standalone BLE tags with inbuilt alert features or phones’ inbuilt beacon. Google and Apple rolled out a framework called exposure notification to empower BLE based contact tracing solutions. These BLE beacon-based solutions are relatively cheap and easy to manage, but are prone to error, and have serious privacy concerns.

The location estimated using BLE beacons can off by as much as 2 m. Since the social distance suggested by CDC is 6 ft (1.8 m), the BLE beacons give erroneous results, false-positive as well as false-negative. One of the experiments done at our lab, we found that a beacon-based social distancing solution gave wrong alerts 75% of the time! The beacons were giving false positives even when the tags were at a 10 ft or farther distance!


Ultra-Wideband technology (UWB) is a radio technology that uses a low energy level for short-range, high-bandwidth communications over the radio spectrum (3.1 to 10.6 GHz). [5] The UWB technology can be used to determine spatial parameters such as distance and location with high accuracy, the error is as low as 10 cm.

Thanks to wide range frequency, UWB has a smaller likelihood of noise interference which makes it apt for indoor application. For social distancing and contact tracing technology in an office or factory environment, we want an IoT technology that can reliably communicate in an indoor setting and can determine distance and location with high precision. Thus UWB has turned out to be an excellent solution for social distancing and contact tracing.

Tracing Solutions

Many social distancing and contact tracing solutions are cheap–as low as $100/user. If you look at the risk of an outbreak of COVID-19 infection at a workplace, and the potential cost of quarantining infected employees, $100/user is negligible. Often an office pays way more than that for coffee and snack supplies.

There are many options available on the market ranging in price and accuracy. Choosing a provider means putting your faith in their technology and ability to deliver accurate results. Research has shown that although BLE devices are more cost-effective to build, they are not as reliable as solutions built with UWB. There are two major challenges. Firstly, BLE based solutions are inaccurate and give both false positives and negatives. Secondly, there are serious privacy concerns about phone-based apps. The COVID-exposure APIs rolled out by Apple and Google in the month of, once hailed by everyone, never took off. One of the studies suggested that Americans don’t trust contact tracing apps.


The COVID-19 pandemic is growing at an exponential rate. To be able to reopen businesses safely we must make pandemic protocols (social distancing, masks, sanitization, and contact tracing) foolproof by using IoT based digital PPE. The use of digital PPE dramatically reduces the number of social contacts, reminds users of social etiquette, encourages people to wear masks, and follows proper sanitization protocols.

The use of digital PPE also makes contact tracing accurate and fool-proof. Among all digital PPE for COVID-19 available, UWB based solutions are the most accurate and precise. Digital PPE can help us reopen the economy safely amid the ongoing pandemic.

Apoorva Kiran
Apoorva Kiran
Edge computing and AI researcher
Edge computing and AI researcher