techwatch
Is the ultra-low-power sensor
the future of tracking?
WHILE COMPANIES CONTINUE TO DITHER ABOUT WHETHER
to jump in the RFID game to enhance their supply chain tracking, science marches on. At a recent conference at the Massachusetts
Institute of Technology (MIT), several scientists offered a preview of
the next generation of radio-frequency identification technology—
ultra-low-power radio sensing devices.
This new type of RFID tag consists of a tiny bundle of electronic
components that include control circuits, a battery, and a radio
receiver that weighs about one gram. The tiny tag’s energy requirements are correspondingly minuscule: The device itself consumes less
than one milliwatt of power.
The sensing device was originally developed as part of a federally
funded project to create a tracking system small
and powerful enough to control the flight of an
insect. In tests, the unit was attached to a moth, and
scientists sent flight control commands to the
unit’s receiver in bursts using ultra-wide-band
transmissions.
The same device used to track insects could
potentially be used to track cargo, according to a
recent white paper from MIT, Transforming the
Future of Supply Chains Through Disruptive
Technology, Ultra-Low-Power Sensing. By way of
example, the publication notes that these ultra low-power devices could be attached to a pallet, allowing the unit’s whereabouts to be monitored without the need for handheld or stationary readers.
Instead, data could be transmitted to the Internet
by various means, including using a smart phone as a local relay.
That would be a huge advantage over existing systems, according to
the white paper. The communications network for supply chains has
historically been limited in scope by constraints on sensing power and
the ability to collect data from sensors, according to Jim Rice, deputy
director of MIT’s Center for Transportation & Logistics. If you remove
these constraints, he says, all kinds of new possibilities open up. On
top of that, eliminating this equipment would reduce infrastructure
costs and remove a common source of data transmission delays.
As for what led the MIT scientists to focus on freight tracking as a
potential use for the technology, it’s all about the power requirements,
says the project’s leader, MIT professor Anantha Chandrakasan. For
tracking purposes, shippers want regular—but not constant—updates
on their freight’s whereabouts. Therefore, the rate
at which shipment-status data needs to be collect-
ed and transmitted is relatively low, and the
power requirements relatively modest. To further
reduce power requirements, the sensors could be
engineered to transmit data in bursts and then go
to sleep between transmissions.
