The tiny burst of power present in Wi-Fi transmissions has been augmented with noise, enough that the enhanced broadcast can animate connected devices, according to a new study emerging from researchers at the University of Washington.
It's the first of its kind. The power-over-Wi-Fi system, dubbed "Po-Wi-Fi," uses existing Wi-Fi hardware to power devices wirelessly, according to findings published in a paper titled "Powering the Next Billion Devices with Wi-Fi."
"Specifically, we show that a ubiquitous piece of wireless communication infrastructure, the Wi-Fi router, can provide far field wireless power without compromising the network's communication performance," stated a study author.
The researchers noting similar work, in which ambient power from TV and cellular signals were used to power remote devices, set out to enhance the power transferred by filling in the blanks. Because Wi-Fi relays bursts of information over different channels, the researchers patched in noise on any free frequencies to keep the power streaming out.
The system has been optimized to have minimal impact on network performance, according to the researchers. The UW researchers performed a number of feats in proving the viability and potency of Po-Wi-Fi.
The scientists charged up a JawBone UP24 via Wi-Fi, from up to 28 feet away, refueling fitness tracker from zero charge to about 41 percent in two and a half hours. That charging time may not be impressive under other circumstances, but Wi-Fi, something that blankets most residences and most urban areas, the potential to power mobile and birth the next generation of the Internet of Things.
"A key issue is how to power these devices as they become smaller and more numerous; plugging them in to provide power is inconvenient and is difficult at large scale," the research paper states. "We introduce a novel far-field power delivery system using existing Wi-Fi chipsets. We do so while minimizing the impact on Wi-Fi network performance."
The Po-Wi-Fi technology still has a long way to go. And complimenting its technology, MIT researchers have been working on a technique that work on the other side of this IoT equation.
MIT researchers have been developing ultra-efficient chips that preserve about 100 times the power as existing IOT sensors, and still manages to send out Bluetooth and Wi-Fi broadcasts. The researchers found the power savings by all but eliminating the sensors' idle time, time during the chips leak power as they wait to be alerted and asked to do a bit of processing.