A group of researchers at the University of Washington has made a WiFi breakthrough that could result in wireless networks that consume much less power. As it is now, WiFi-enabled devices give up a significant amount of their battery life to stay connected to wireless networks. The researchers have made a passive WiFi discovery that uses 10,000 times less power than current WiFi methods.
The Passive WiFi system is so energy efficient that it uses 1,000 times less power than existing energy efficient comm platforms like Bluetooth LE and Zigbee. The tech is able to transmit WiFi signals at up to 11 megabits per second that can be decoded by any device with WiFi connectivity. While 11Mbps is slow by WiFi standards, it is 11 times faster than Bluetooth.
The new tech could save battery power on existing wireless devices and help the Internet of Things take off by removing some of the power constraints that are a challenge today. The team decoupled digital and analog operations that are involved in radio transmission to achieve the low power operation. Passive WiFi assigns the high-power consuming analog functions to a single device in the network that is connected to a wall outlet.
In testing, the team found that the passive WiFi sensors were able to communicate at distances up to 100 feet apart. “All the networking, heavy-lifting and power-consuming pieces are done by the one plugged-in device,” said co-author 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 new tech could be ideal for home automation and smart home applications. “Even though so many homes already have Wi-Fi, it hasn’t been the best choice for that,” said co-author Joshua Smith, UW associate professor of computer science and engineering and of electrical engineering. “Now that we can achieve Wi-Fi for tens of microwatts of power and can do much better than both Bluetooth and ZigBee, you could now imagine using Wi-Fi for everything.”