Harvesting Wi-Fi Backscatter To Power Internet of Things Sensors

vinces99 (2792707) writes "Imagine a world in which your wristwatch or other wearable device communicates directly with your online profiles, storing information about your daily activities where you can best access it – all without requiring batteries. Or, battery-free sensors embedded around your home that could track minute-by-minute temperature changes and send that information to your thermostat to help conserve energy. This not-so-distant 'Internet of Things' reality would extend connectivity to perhaps billions of devices. 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. But having a way to cheaply power and connect these devices to the Internet has kept this from taking off. Now, University of Washington engineers have 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 these devices. Called Wi-Fi backscatter, this technology is the first that can connect battery-free devices to Wi-Fi infrastructure. The researchers will publish their results at the Association for Computing Machinery's Special Interest Group on Data Communication's annual conference this month in Chicago. The team also plans to start a company based on the technology. The Pre-print research paper.

Comments

Somebody (re)discoverd the crystal radio

[Anonymous Coward]

Powered by radio waves.

WTF is the "Internet of Things"?

[Anonymous Coward]

I mean I hate "Internet of Things". Stupid term created by stupid people for stupid people.

iFind

[enoz]

This sounds just what iFind was promising before they were suspended from kickstarter

Re:iFind

[MattskEE]

It only works because it has a very low bitrate of 1kbps:

The UW’s Wi-Fi backscatter tag has communicated with a Wi-Fi device at rates of 1 kilobit per second with about 2 meters between the devices.

Although the authors claim that "The Wi-Fi Backscatter tags do not require any batteries and can harvest energy from ambient RF signals" they make no attempt to back up this claim with measured or estimated energy efficiency of this transmitter. The standard metric for high efficiency transceivers is joules per bit, because low bitrate communication always consumes less energy than high speed, but the only useful way to compare it to another high efficiency transmitter is to see if it can transmit a certain amount of data for less energy.

While I don't expect every paper to address every aspect of a technology, they should not then turn around and make baseless claims like "We believe that this new capability is critical for the commercial adoption of RF-powered Internet of Things." in a length 12 page paper that fails to address the one metric which would allow them to make such a claim.

Re:Sponsors

[TubeSteak]

If they're talking about launching this commercially, it means the Alphabet Agencies have been doing it for years now.

Re:Sponsors

[Dutch Gun]

Internet of things, huh? I think I'll wait a generation or two until they hammer out the worst of the security issues. One of the latest missteps was caused by a smart bulb that embedded the encryption key in the firmware. Oops. Yeah, no one would think to look there, right? There's likely going to be an entire generation of devices that will have the same sort of flaws that early wireless routers had - essentially, the result of average programmers (i.e. non-cryptographic experts) trying to invent cryptographic solutions.

Re:It's just a phrase

[Opportunist]

no, the intent is not stupid.

It's malicious.

Don't get me wrong, I'd love to have my gadgets talk to each other. But in this day and age, I doubt that I get to choose the topic.