University of Washington engineers show how “smart” posters can send a message via FM radio waves to smartphone or car radio
(Smithsonian Magazine) One day, signs may be able to talk to us through our phones and our car radios.
Okay, so this may not be a technological breakthrough you’ve long awaited. Given how much time we already spend interacting with devices, you may be wondering if we really need to have more opportunities for inanimate objects to communicate with us.
Allow Vikram Iyer to explain.
“We think this is a technique that can really be used in smart cities to provide people with information when they’re outdoors,” he says.
Iyer is part of an engineering team at the University of Washington that just published a study showing how FM radio waves can be used to transmit data and audio from a sign, or even clothing.
The research shows that it is possible for a smart phone or a car radio to play a message sent from a “smart” poster via FM radio signals, instead of relying on WiFi or Bluetooth to transmit it. This involves a technique known as “backscattering,” where audio and data are transmitted on top of existing FM broadcast signals.
“With Bluetooth and WiFi, all the energy has to come from the battery,” Iyer explains. “But we used the energy already being blasted out by those big FM antenna towers.”
The result is that backscattering requires much, much less energy, meaning an outdoor poster or sign could share a message for years while using next to no power.