Passive Wi-Fi consumes 10,000 times less power while keeping fast speeds
These days, Wi-Fi is everywhere. It connects all of our devices to the Internet and to each other. This has allowed us to get rid of wires, stream movies and music on demand, connect without cell service and accomplish a wide range of tasks with our smartphones.
The downside of all of that Wi-Fi connectivity is the power it consumes, draining batteries and upping the power consumption of formerly "dumb" devices.
Computer engineers at the University of Washington have developed a new Passive Wi-Fi system that is able to maintain fast data speeds while consuming 10,000 times less power than conventional Wi-Fi, in some instances consuming almost no power at all. The team believes it will allow an “Internet of Things” reality "where household devices and wearable sensors can communicate using Wi-Fi without worrying about power."
The system also consumes 1,000 times less power than energy-efficient platforms like Bluetooth Low Energy and Zigbee and has been lauded by the MIT Technology Review which has named it one of the 10 breakthrough technologies of 2016.
It transmits Wi-Fi signals at a rate of 11 megabits per second and is compatible with any devices with Wi-Fi connectivity right out of the box. While these speeds are below the fastest Wi-Fi available today, it's 11 times faster than Bluetooth.
The engineers accomplished this by decoupling the digital and analog operations in Wi-Fi. The digital side had already become very efficient, but the analog side was holding it back. The Passive Wi-Fi performs all of the analog operations in a single device plugged into the wall. An array of sensors then produces Wi-Fi packets of information, reflecting and absorbing the signal using a digital switch and using very little power.
“All the networking, heavy-lifting and power-consuming pieces are done by the one plugged-in device,” said Vamsi Talla, an electrical engineering doctoral student. “The passive devices are only reflecting to generate the Wi-Fi packets, which is a really energy-efficient way to communicate.”
The technology could one day soon be used in smart home applications like smart appliances, door locks, heating and cooling and more, reducing their energy consumption while keeping them connected. The researchers also think this will lead to new types of communication that weren't possible before because of the high power demand.