Engineers have designed a new communication system that uses radio frequency signals as a power source to provide Internet connectivity to battery-free devices. Technology Briefing
Transcript
If the Internet of Things is going to achieve its full potential,
we'll need to provide connectivity to the as many as a trillion
battery-free devices embedded in everyday objects.
Now, a team of University of Washington engineers has designed a new
communication system that uses radio frequency signals as a power source
and reuses existing Wi-Fi infrastructure to provide Internet
connectivity to battery-free devices.
This technology is called Wi-Fi backscatter, and it's the first technology that can connect battery-free devices to Wi-Fi infrastructure.
It enables Wi-Fi connectivity for devices, while consuming orders of
magnitude less power than what Wi-Fi typically requires. Using this
approach, sensors could be embedded in everyday objects to help monitor
and track everything from the structural safety of bridges to the health
of your heart.
The researchers recently presented their results at the SIGCOMM'14 conference in Chicago. They are now in the process of starting a company based on the technology.
This work builds upon previous research that showed how low-powered
devices, such as temperature sensors or wearable technology, could run
without batteries or cords by harnessing energy from existing radio, TV,
and wireless signals in the air.
The challenge in providing Wi-Fi connectivity to these devices is
that conventional, low-power Wi-Fi consumes three to four orders of
magnitude more power than can be harvested in these wireless signals.
The researchers instead developed a prototype of an "ultra-low power
tag" with an antenna and circuitry that can talk to Wi-Fi-enabled
laptops or smartphones while consuming negligible power.
These tags work by essentially "looking" for Wi-Fi signals moving
between the router and a laptop or smartphone. They encode data by
either reflecting or not reflecting the Wi-Fi router's signals, slightly
changing the wireless signal. Wi-Fi-enabled devices like laptops and
smartphones would detect these minute changes and receive data from the
tag.
In this way, your smart watch could download e-mails or offload your workout data onto a Google spreadsheet.
So far, the University of Washington Wi-Fi backscatter tag has
communicated with a Wi-Fi device at rates of 1 kilobit per second, with
about two meters between the devices.
They now plan to extend the range to about 20 meters, and they have patents filed on the technology.
Comments
Wouldn't this be considered "power theft", legally? If I were a broadcast operator, and if the devices go into the trillions, my transmit power would have to be increased substantially. That translates directly to operations cost...
