Feeds

Boffins harvest TV, mobile signals for BATTERY-FREE comms

Powerless tech better than your common-or-garden RFID tag, claim researchers

5 things you didn’t know about cloud backup

Radio boffins from the University of Washington have created tags and readers which reflect and feed off ambient radio frequency energy for communications - without needing a power source.

The team calls the technology "ambient backscatter" and reckons it could connect up the much-heralded Internet of Things without either party needing a power supply.

Two tags can absorb, or reflect, existing transmissions from (for example) a TV broadcaster to convey information to each other, while using the power absorbed to process the signals, as demonstrated in this jolly video.

Absorbing power from TV transmissions is very old news. Back in the '60s Practical Wireless ran a feature on the subject. More recently, Intel managed to pull 25uA, at 1.5v, from a local TV transmitter – apparently just for fun.

Pulling power from a TV signal generates a shadow, sucking the signal from the surrounding area. The effect is very localised but it's that removal of signal which the Ambient Backscatter system perceives as a transmitted Zero. A "One" is sent by reflecting the signal, and thus binary communications is possible.

Communication by reflected signal is also old news; various forms of RFID tag work this way. Which is why, unlike NFC tags, they can be read from such a huge distance with a high-powered signal. Californian outfit Kovio has even managed to print such tags for 5 cents a time.

But those technologies all require a powered reader, while the Washington boffins reckon their powerless tech is inherently superior. They suggest an unpowered sofa could communicate with an unpowered keyfob to tell a home hub of some sort that the clumsy homeowner has left the key behind.

That sounds good, as long as every device knows the frequency of a suitable transmission nearby, or can scan for available transmissions, though that would take power which rather defeats the object.

Radio is getting much more energy efficient: the Weightless protocol, for example, will keep one's keyfob connected to a national network for seven years or so on a single battery, which challenges the principal advantage of ambient power.

But this is research, and doesn't need immediate application to be interesting. It's another way for devices to communicate, and with tens of billions of devices joining the internet over the next few decades new communications should always be welcomed. ®

5 things you didn’t know about cloud backup

More from The Register

next story
6 Obvious Reasons Why Facebook Will Ban This Article (Thank God)
Clampdown on clickbait ... and El Reg is OK with this
So, Apple won't sell cheap kit? Prepare the iOS garden wall WRECKING BALL
It can throw the low cost race if it looks to the cloud
EE fails to apologise for HUGE T-Mobile outage that hit Brits on Friday
Customer: 'Please change your name to occasionally somewhere'
Time Warner Cable customers SQUEAL as US network goes offline
A rude awakening: North Americans greeted with outage drama
We need less U.S. in our WWW – Euro digital chief Steelie Neelie
EC moves to shift status quo at Internet Governance Forum
BT customers face broadband and landline price hikes
Poor punters won't be affected, telecoms giant claims
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?