IoT devices could communicate using ambient radio waves
Image credit: Dreamstime
Researchers have demonstrated the potential for IoT devices to ditch power-draining radio sensors and instead communicate using background radio waves from TV, radio and mobile phones.
The emergence of the Internet of Things (IoT) – an interconnected population of devices, vehicles and other smart objects – promises to change the way we live. Connecting all our belongings, however, is a considerable task and remains impractical in many respects.
Most IoT systems are linked using radio sensors. These radios consume most of the devices’ battery power and limit their usability as smart devices are drained of power rapidly.
In order to tackle this problem, researchers at Disney Research, the research and development branch of The Walt Disney Company, set about creating an ultra low-power system which transmits data by harnessing the ambient radio waves already bathing most office and home environments.
Using these signals – generated by commercial broadcasting systems and mobile phones – enormously reduces the power requirements of the devices.
“Ambient backscatter” detects existing radio signals and converts these into tens or hundreds of microwatts of power. This is then used to modify and reflect the signal, which can in turn be picked up by other devices using antennae.
“Our idea is to reuse all the radio signals that are around us as a medium for transmitting data, much like sending ripples across a pond,” said Dr Alanson Sample, leader of Disney Research’s wireless systems group.
Previous attempts to use ambient backscatter for communicate devices have suffered from low range, making the method impractical for IoT devices. To address this limitation, the researchers created an ultra-wideband (UWB) ambient backscatter system. This system backscatters all ambient sources, boosting signal-to-noise ratio, and as a result extending the range to 22-50m, depending on which ambient radio signals are used.
The system can be powered by just a solar cell, optimised for low-light conditions.
“The promise of the Internet of Things is that wireless sensors will be ubiquitous, allowing devices to sense their environments and talk to each other,” said Markus Gross, vice president at Disney Research.
“As we move towards connecting the next billion wireless devices to the internet, however, the use of batteries to power these devices will become unworkable. UWB ambient backscatter systems, which potentially could be deployed in any metropolitan area, hold great potential for solving this dilemma.”
The researchers presented details of the new system at Infocom 2017 – a computer communication conference – in Atlanta, USA, and demonstrated the system using ambient signals from radio towers and two mobile phones.
As the hardware does not need to be tuned to a specific frequency, instead using all available radio sources, the system can be deployed in almost any metropolitan area, the researchers say.