New Passive Wi-Fi technology operates at 10,000 times less power than conventional wireless networks


Today, Wi-Fi is everywhere, allowing people to stream movies on their smartphones, connect laptops to printers and so on. Despite its ubiquitous presence, this wireless computer networking technology is known to consume large amounts of energy, and is responsible for draining the batteries of all connected devices. A team of researchers at the University of Washington has come up with an innovative new technology that promises efficient Wi-Fi transmissions at 10,000 times less power than traditional methods.

The new system, aptly called Passive Wi-Fi, uses nearly 1,000 times less energy than even the most power-efficient wireless communication platforms existing today, including Zigbee and Bluetooth Low Energy. According to the scientists, the technology is capable of transmitting Wi-Fi signals at speeds of around 11 megabits per seconds to billions of devices connected to a particular network. Speaking about the research, which will be presented at the 13th USENIX Symposium on Networked Systems Design and Implementation in March, Shyam Gollakota, a professor of computer science and engineering, said:

We wanted to see if we could achieve Wi-Fi transmissions using almost no power at all. That’s basically what Passive Wi-Fi delivers. We can get Wi-Fi for 10,000 times less power than the best thing that’s out there.

Passive Wi-Fi Uses 10000 Times Less Power Than Today's Wi-Fi Networks-1

While the transmission speeds of Passive Wi-Fi are lower than the currently-available maximum Wi-Fi speeds, the system can transfer data up to 11 times faster than Bluetooth. To develop the low-power technology, the team disengaged the digital and analog operations associated with radio transmissions. Technological advancements over the last 20 years have made the digital half of the equation incredibly energy-efficient. The analog side, however, continues to consume substantial quantities of power.

Unlike conventional Wi-Fi connections, the new system relies on a single wall-mounted device for all of its power-intensive, analog tasks, like generating a signal of a particular frequency. Using negligible amounts of energy, several sensors then produce small packets of Wi-Fi networks, with the help of a specially-designed digital switch that reflects and absorbs the signal. When tested on the university’s campus, the technology was found to work even when the user’s smartphone and the Wi-Fi sensors were more than 100 feet apart. Vamsi Talla, the study’s co-author and an electrical engineering research student at UW, said:

All the networking, heavy-lifting and power-consuming pieces are done by the one plugged-in device.The passive devices are only reflecting to generate the Wi-Fi packets, which is a really energy-efficient way to communicate.

Thanks to its energy-efficient credentials, the Passive Wi-Fi system could pave the way for new types of communication between devices that until now were restricted because of high power consumption. What is more, it could make “Internet of Things” a household reality, where appliances can be controlled remotely using wearable sensors via low-power Wi-Fi networks. Bryce Kellogg, another electrical engineering student at the University of Washington, added:

Our sensors can talk to any router, smartphone, tablet or other electronic device with a Wi-Fi chipset. he cool thing is that all these devices can decode the Wi-Fi packets we created using reflections so you don’t need specialized equipment.

The research, which was jointly funded by Qualcomm, the University of Washington and the National Science Foundation, could facilitate wireless communication at remarkably low power. Joshua Smith, a professor of computer and electrical engineering, explained:

Even though so many homes already have Wi-Fi, it hasn’t been the best choice for that. 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.

Source: University of Washington

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