Ambient backscatter threatens end of batteries -

A team of researchers at the University of Washington have emerged from their smoke filled labs with a new wireless communication system that allows devices to interact with each other without relying on batteries or wires.

The gear uses ambient backscatter technology to interact with users and communicate with each other without using batteries. They exchange information by reflecting or absorbing pre-existing radio signals.

This takes advantage of the TV and mobile transmissions that already surround us. The two devices piggy back on the existing signals using built small, battery-free devices. They need antennas that can detect, harness and reflect a TV signal and that is all.

It means that it could be possible to have a network of devices and sensors to communicate with no power source or human attention.

Lead researcher Shyam Gollakota, a UW assistant professor of computer science and engineering, said that it is possible to repurpose wireless signals that are already around us into both a source of power and for communication.

This will be important in areas like wearable computing, smart homes and self-sustaining sensor networks.

The team published their results at the Association for Computing Machinery's Special Interest Group on Data Communication 2013 shindig in Hong Kong, MIT Technology Review reports.

They received the conference's best-paper award for their research.

Everyday objects could also be enabled with battery-free tags to communicate with each other. One example is a sofa which could use ambient backscatter to let the user know where they left a set of keys.

The receiving devices picked up a signal from their transmitting counterparts at a rate of 1 kilobit per second when up to 2.5 feet apart outdoors and 1.5 feet apart indoors. This is enough to send information such as a sensor reading, text messages and contact information.