Passive Wifi May Connect Your Home to the Internet of Things With Very Low Power

Wifi-powered and -transmitting beacons will enable everyday objects to "speak wifi."

Wikimedia Commons

A team at the University of Washington Computer Science and Engineering school just invented something that could make your home more communicative — inviting everyday objects onto the Internet of Things — and your local library or university more connected. The invention: Passive wifi.

It’s actually not as lame as it sounds. It was named one of the ten breakthrough technologies of 2016 by MIT’s Technology Review. (Passive-aggressive wifi, however, may have been a better choice.) With passive wifi, miniature router-esque devices receive and retransmit wifi signals from standard routers. These devices require 10,000 times less power than standard routers. The devices require so little energy because they employ a technique known as “backscattering,” by which they acquire power from the signals they’re receiving and retransmitting.

In addition, they don’t just propagate the same network: they serve as beacons with their own independent, equally formidable networks. Your phone, laptop, or tablet, in other words, can connect to the beacon’s own network.

An "ultra–low-power" beacon.


Within libraries or large coffee shops, this invention will be useful. Instead of having several consumptive routers scattered about, these public spaces can throw numerous beacons around the space. Each will put out a strong signal and connection.

And, in the eyes of its makers, passive wifi will allow your household objects to virtually speak to you, even though the objects themselves are not plugged in.

“Passive wifi enables a diverse range of everyday objects to be able to speak wifi and intelligently connect to the internet. Now, paper towels, coffee, or sugar can communicate their status using wifi, and alert the user.”

Here’s how it works:

Passive wifi will soon be commercially available through a company called Jeeva Wireless, though its current website offers little information.