Using ambient backscatter, these devices can interact with users and communicate with each other without using batteries. They exchange information by reflecting or absorbing pre-existing radio signals.

Using ambient backscatter, these devices can interact with users and communicate with each other without using batteries. They exchange information by reflecting or absorbing pre-existing radio signals.

One of the things holding back a more widespread push towards the Internet of Things — making everyday objects smarter and network connected — is battery technology. Computing power, and lately storage capacity, have increased and are still increasing exponentially. However battery technology has lagged behind.

If you pry open your laptop you’ll find a lot more of it is dedicated to the battery than it was a few years back. While the electronics inside your laptop have decreased in size, and so also has the amount of power it’s using for basic computer, overall your laptop is doing so much more for you these days (wifi/4g connectivity, higher-resolution screens running bigger video, longer-expected daytime use) and the power needs have increased, not decreased.

While technologies like Bluetooth Low Energy have arrived to decrease the amount of power needed — designed for use in embedded devices Bluetooth LE lives up to its name, allowing embedded devices to last for weeks or months on a single coin cell — one of the main drains on that battery is wireless.

Which isn’t necessarily a problem for laptops, but when it comes to the Internet of Things and the almost-inevitable evolution towards Smart Dust, then it is a problem. If computing is ever truly going to become ambient, then how to power it is a major stumbling block.

While tiny solar cells and other passive power generation techniques, like vibration harvesting, have already been scaled down fairly successfully, anything that can reduce the power requirement is going to be looked at with a lot of interest.

A team at the University of Washington has just come up with something that is certainly going to generate that sort of interest. They’re using existing TV and cellular transmissions — ambient RF energy that’s in the air around already — both as a communication medium, and as a source of power.

Unlike NFC, where power is supplied by the reader device, here neither the reader nor the transmitter are powered. Both devices are battery free, and while the data rates are fairly low, they’re communicating at much higher ranges than NFC is capable of, with reliable transmission of several feet. That’s pretty impressive.

If developed properly, this technology could enable a lot of new use cases for the Internet of Things, including the permanent installation of embedded devices in hard-to-service areas: inside walls and other structures, and also in everyday objects.

Everyday objects communicating wirelessly using ambient backscatter

Everyday objects communicating wirelessly using ambient backscatter

If the person loses their keys, the couch can can use ambient backscatter to communicate with the lost keys, and then alert the user. This technology could enable smart homes, smart cities—and an Internet of Things.

This new technology arriving could also mean that the growing ubiquity of NFC could be short-lived.

(via The University of Washington)

Original paper: Ambient Backscatter: Wireless Communication Out of Thin Air, Liu, Parks, Talla, Gollakota, Wetherall & Smith, 2013, Proceedings of the ACM SIGCOMM Conference

Alasdair Allan

Alasdair Allan

Alasdair Allan is a scientist, author, hacker and tinkerer, who at the moment is spending a lot of his time thinking about the Internet of Things. In the past he has mesh networked the Moscone Center, caused a U.S. Senate hearing, and contributed to the detection of what was—at the time—the most distant object yet discovered.


  • http://dailyack.com/ Alasdair Allan

    Interestingly, thinking about this a bit more, it is also rather stealthy. If there are no new RF signals being generated, just ambient signals reflected and backscattered, then unless you know what to look for these things are pretty much invisible. At least at the moment, I’d guess that once the technology is more common the finger print will become more noticeable.

  • https://www.facebook.com/paul.sandkuijl Paul Dutch Sandkuijl

    I wonder if it interferes with the original messages in the “back scatter”..
    If all of of use these, wouldn’t it be impossible to send reliable messages via the “normal” way because the devices in between scatter the signal?

    • http://dailyack.com/ Alasdair Allan

      If you look at the original paper there are some measurements of interference, but they look to be minimal, “Since the backscattered signals are reflections of existing TV signals, in theory, one could either synchronize ambient backscatter with the TV transmissions or modulate data at a slow enough rate that TV receivers would be immune to interference. However, even without these constraints, the backscattered signals are weak enough that they do not affect TV receivers except in less favourable conditions. “

  • Tommy Phillips

    This is brilliant. I do wonder about the limits of shrinking the physical size. Electomagnetic wave reception and transmission are highly dependent on the size of the antennas, no matter how clever the design (and I know that antenna design was still in the stone age when I studied RF back in the 80’s, compared to today’s technology.)

  • http://gravatar.com/kevinlkoehler Kevin L Koehler

    your chocolate’s in my peanut butter..
    no, your peanut butter’s on my chocolate

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  • Wynn

    Qeng Ho Localizers

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  • kunal patil

    whats the estimation (budget) of this project????

  • kunal patil

    whats the estimation (budget) of this project ????

  • sai

    what is the cost of product is it available in market?