Proving the Business Case for the Internet of Things

STM reference design uses Sigfox for contact tracing

Steve Rogerson
June 16, 2020

Swiss semiconductor firm ST Microelectronics has introduced a reference design that uses Bluetooth LE and the Sigfox network for monitoring social distancing and providing contact tracing in response to global or local pandemics.
Leveraging Bluetooth Low Energy technology through its system-on-chip with tunable RF output power, the Blue NRG-Tile reference design measures the signal strength of nearby Bluetooth non-connecting beacons and in real time calculates proximity to these sources.
The circuit can issue warnings when another beacon intrudes on an adjustable perimeter or when tampered with, even when not connected to a smartphone or 5G network. The base reference design can be supplemented with the S2-LP sub-GHz low-power RF transceiver to add bi-directional tag-to-cloud communications through the Sigfox 0G global network, allowing private and anonymous tag provisioning, notifications, and an advisory return-channel for emergency warnings.
To assure power economy and extend battery lifetime, the low-power components are enhanced with a MEMS (micro-electro-mechanical systems) accelerometer that power cycles the unit when it isn’t moving. Optionally, internal or external memory could provide long-term storage of nearby beacons, allowing contact tracing.
“Developing this highly-efficient and cost-effective social distancing reference design has significant value in any environment where people need to work safely,” said Benedetto Vigna from ST Microelectronics. “This compact design can be used as is or enhanced for a wide range of applications, including as bracelets and bands or as plugins or add-ons to eyeglasses, helmets, masks and shields.”
Several members of the company’s partner programme have evaluated and adopted the reference design as a foundation for location-monitoring and contact-tracing platforms. These platforms provide a range of capabilities, including proximity alerts and contact recording, using the STM reference design packaged in compact low-power tags.
In 2019, STM’s net revenues were $9.56bn, serving more than 100,000 customers worldwide.