It uses non-connecting Bluetooth modes, measuring signal strength to estimate the proximity of similar devices in real time – acting on three adjustable virtual ranges: safe (>3m), pre-alert (3m) and alert (2m).
“The nodes simultaneously advertise their presence and scan for the presence of other similar beacons in range, while deploying low-power modes during periods of inactivity to conserve battery power,” according to the company. “Advertising is performed on three channels and no connection or response packet are required between the devices during advertising and scanning activities.”
Adding Sigfox provides bi-directional device-to-cloud communication (through the ‘0G’ global network) allowing private and anonymous provisioning, notifications, and an advisory return-channel for emergency warnings.
The accelerometer is there as a movement detector to save power when the device is motionless.
“Optionally, internal or external memory could provide long-term storage of nearby beacons, allowing contact tracing,” said ST, which describes the whole concept in detail using its the integrated circuits in its STEVAL-BCN002V1B sensor node development kit (pictured).
According to the company, several members of its partner programme have adopted the scheme as a foundation for location-monitoring and contact-tracing platforms.
Source: This news is taken from www.electronicsweekly.com
