Can you imagine a world where various devices are interconnected forming a grid so that sharing of data and automation become easy? This is the concept of Internet of Things in which a wide variety of devices are interconnected with each other wirelessly within the existing internet network.
In the ‘Internet of Things’, such ‘Things’ could be an automobile with a built-in sensor, a farm animal with embedded biochip transponder, a human with a heart monitoring implant or a wearable to which an IP address can be assigned and which can transfer data over an internet network. Unfortunately, this concept has not yet gathered momentum because such devices need power as well as connection to the internet.
As an important step in this direction, engineers at the University of Washington have developed a new communication system called the ‘Wi-Fi Backscatter’ technology through which battery-free devices could be connected to an existing Wi-Fi infrastructure by using radio frequency (RF) signals as the power source.
An earlier research has shown that energy from TV, radio and other wireless signals in the air could be harnessed to run low-powered devices such as temperature sensors or wearables. Researchers at the University of Washington have gone a step further and connected these devices to the WI-Fi network.
It was a challenging task as wireless signals are very weak and even low power Wi-Fi needs 3 to 4 times more power than what could be harnessed through these RF signals. So they developed a new Wi-Fi Backscatter mechanism. They devised an ‘ultra-low power tag’ having an antenna and a circuit to detect signals between Wi-Fi router and a smartphone or a laptop and communicate data to them. These tags consume very little power.
Shyam Gollakota, assistant professor of computer science and engineering at the University says “If Internet of Things devices are going to take off, we must provide connectivity to the potentially billions of battery-free devices that will be embedded in everyday objects.”
“We now have the ability to enable Wi-Fi connectivity for devices while consuming orders of magnitude less power than what Wi-Fi typically requires”, he adds.
The Wi-Fi Backscatter tag developed by the University of Washington engineers has been able to communicate at rate of 1 kbps with a Wi-Fi device about 2 meters away. They are now planning to increase the distance to about 20 meters. The research team plans to launch a company for their technology and file patents for it.
The video below demonstrates the how the Wi-Fi Backscatter technology works: