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contact-tracing

Ensuring Workplace Safety: An Approach to Accurate Contact Tracing

May 21, 2020
Bluetooth and UWB-based contact tracing solutions can struggle to overcome absorption, reflection, and bandwidth limitations in real-life indoor environments. See how WiFi can overcome these limitations.

COVID-19 has forced many industries to shut down or significantly reduce operations—now that cities are beginning to open certain aspects of society, it is crucial we implement comprehensive “Test and Trace” methods, especially for industrial and commercial spaces. Although various testing methods are being scaled successfully, the current contact tracing process is manual, tedious, and inefficient.

Bluetooth-based solution—it’s not for everyone

One approach that’s generated mass attention is Apple and Google’s jointly announced Bluetooth-based solution. This solution uses Bluetooth to periodically capture an identifier of other Apple or Android smartphones in the vicinity, which can be later used to assess possible exposure if a positive patient advertises their COVID diagnosis. This solution is noteworthy in its approach to consumer privacy and emphasis on decentralized contact tracing.

However, for any Bluetooth-based solution, one major limitation is poor indoor positioning accuracy in commercial and industrial spaces, such as warehouses, distribution centers, factories, office buildings, hospitals, retail stores, and hotels. Bluetooth solutions are based on either RSSI (Relative Received Signal Strength Indication) or AOA (Angle of Arrival) measurements.

A key requirement of any proposed indoor wireless contact tracing solution should be robust indoor accuracy of better than six feet. However, these Bluetooth solutions have limited positioning accuracy (10 to 100 ft) due to absorption, line of sight blockages, and multi-path reflections in indoor spaces. These cumulative inefficiencies could result in significant levels of false positives and false negatives in wireless-based contact tracing, potentially causing confusion, anxiety, and disruption.

Additionally, COVID-19 spreads easily through community transmission where people contact objects and surfaces that have been touched previously by an infected person.

Accurate indoor positioning and contact data is therefore essential to also identify objects and spaces of potential transmission for effective cleaning and disinfection—and that starts by using a WiFi-based solution.

Why WiFi-based solutions should take the spotlight

The WiFi-based contact tracing approaches are very promising for several reasons.

First, as shown in Figure 1, improvements in advanced analytics and WiFi quality enable WiFi-based local positioning solutions to effectively demonstrate robust sub-meter (approx. 3 ft) positioning accuracy in complex indoor environments, including warehouses, distribution centers, factories, food processing plants, hospitals, and office buildings.

These advances allow WiFi to overcome the inherent limitations of GPS and Bluetooth-based approaches to monitor real-time worker and asset position, movement, and occupancy at sub-meter levels, as shown in Figure 2.

Contact and occupancy data can be tracked in real-time (i.e. on a per-second basis) on a historical basis, and can be easily integrated with internal enterprise-level and other databases (i.e., Public health) for additional contact tracing analytics. Another key benefit of the WiFi-based solution is the ability to proactively monitor the workspace in real-time to enable compliance with social distancing rules and accurately identify potential hot spots. This is particularly important in industrial spaces where workers are moving and changing locations frequently. Additionally, all commercial and industrial spaces have existing WiFi infrastructures. This is very important as enterprises need to also assess the ease of deployment and total cost of ownership fo deploying these solutions. Most workers utilize WiFi-enabled smart devices, including mobile phones, and battery-operated WiFi-based trackers can be provided to workers who don’t have access to one. These devices connect to the secure networks in an opt-in scheme deployed and monitored by corporate IT groups. This approach resolves the required levels of worker consent, privacy, and participation for robust contact tracing by encouraging workers to opt-in to securely monitored WiFi networks. It has been widely acknowledged that a key challenge for a consumer-focused Bluetooth based solution is the level of network, such as the use of participation required to achieve meaningful contact tracing. In contrast, WiFi-based enterprise-level solutions are well-positioned to achieve the required high-level of employee participation. Lastly, WiFi’s ubiquitous deployment and global standardization allow corporations and organizations to build globally meaningful contact tracing approaches for commercial and industrial spaces as workers are required to travel and physically engage with each other across the world.

In summary, WiFi-enabled wireless contact tracing holds significant potential for effective and scalable contact tracing in indoor commercial and industrial spaces. It can be further enhanced with other complimentary consumer-level and public-health service initiatives. This will require cooperation between various key industry stake-holders as we jointly strive to re-open commercial and industrial spaces safely and efficiently.