Who needs radio communications? IoT sensors could connect via ambient waves getting rid of the radios altogether, according to a new study from Disney Research.
A team of researchers, led by associate lab director and leader of Disney Research’s Wireless Systems group Alanson Sample, devised an ultra-low-power system of sensors that transmit data to a central receiver by reflecting the ambient radio waves from commercial broadcasting systems that already bathe most office environments.
The idea is to reuse the all radio signals around as a medium to transmit data, said Sample.
Since it is the generation of radio waves that consumes most of their battery power, this approach radically reduces the power requirements of the sensor nodes. In a demonstration, the researchers met the tiny bit of remaining power demand by using solar cells optimized for low-light conditions.
The details of the researchers’ ultra-wideband (UWB) ambient backscatter system was presented at the IEEE Conference on Computer Communication, INFOCOM 2017, demonstrating the system using ambient signals from 14 radio towers along with two mobile phones in an indoor environment.
TV station is a system which is a single source that requires less power by using ambient waves. But the range is limited until the power of ambient signals is boosted to high levels.
According to Sample, UWB approach, which backscatters all ambient sources, offers key advantages. Multiple backscatter channels boosts signal-to-noise ratio, substantially improving the sensitivity of the backscatter reader and decreasing dead zones. This enables the system to operate on real-world ambient sources and substantially extends the range to 22 metres when using ambient signals from broadcast towers and 50 metres when using ambient signals generated by mobile phone up-link traffic.