University Engineering Prof. Maite Brandt-Pearce and her former graduate student, Mohammad Noshad, have found a new alternative to wireless networks like Wi-Fi which uses radio waves. Their new technology “Li-Fi” instead uses LED lights to provide network connectivity.
In wireless networks like Wi-Fi, a wireless adapter converts data into radio signals and transmits it using an antenna. A wireless router then receives and decodes the signal, sending the information to the internet with a physical, wired connection.
Getting consistent coverage with Wi-Fi can often be frustrating and difficult, since these networks are interrupted by black spots where no signal is available. Wireless transmissions also can be slower than wired connections, especially when many people are trying to access the same network at the same place. There are also safety concerns with Wi-Fi, as Wi-Fi signaling can be harmful in the long run due its reliance on electromagnetic radiation.
“There are so many spaces where Wi-Fi is not allowed and having friends that work in that space ... It’s very frustrating to always be hard wired,” Brandt-Pearce said.
Brandt-Pearce and Noshad’s LED approach to wireless networking — called Li-Fi — may be on its way to solving these existing problems. Li-Fi is high-speed and fully-networked wireless communication technology that utilizes UV visible light, infrared or near-ultraviolet communication to transmit data.
“You will receive data from special lights that VLNComm is building,” Noshad said. “It will look like the same lights that you currently have in your house but they have another feature added that basically provides internet connection.”
Brandt-Pearce, Noshad and entrepreneur Fraidoon Hovaizi have created VLNComm LLC, which aims to make an alternative or supplement to Wi-Fi that increases the availability of communication and information transfer. The company develops new signal processing and coding for LED Li-Fi systems and eventually plans to manufacture many different Li-Fi products within five years.
“There was just an empty space that was ready for somebody to add something to that space,” Brandt-Pearce said.
VLNComm advocates for a number of advantages to this Li-Fi approach. For one, Li-Fi offers higher security than Wi-Fi. While Wi-Fi signals can easily pass through walls, Li-Fi is secured as long as the LED lights used for wireless connectivity do not leave a room.
“Li-Fi doesn’t go through your walls or your skin,” Hovaizi said.
Li-Fi can also increase the speed of internet connection due to the broad bandwidth of the visible light wavelength, which stretches from 780nm to 375nm. It can also support more people using a network signal. While WiFi only works properly in areas that have at least one router, Li-Fi allows many people to connect wherever there are specialized LED lights.
Li-Fi is eco-friendly as well. Lighting and Wi-Fi both consume energy, but Li-Fi only requires the energy generated from the lighting.
“It’s a dual purpose,” Noshad said. “The same energy used for illumination and lighting can be used for communication as well.”
The eco-friendly nature of Li-Fi has attracted global organizations and government agencies such as the Department of Energy to fund VLNComm’s projects and research.
“The green aspect of that has triggered many interests in this system,” Hovaizi said.
Even though network connectivity using Li-Fi requires light, VLNComm is also exploring ways to connect to networks without LED lighting.
“Eventually, we might embed from infrared transmitters so that even when you have the visible light off to watch a movie in the dark, you can dim the LED or embed another wavelength like an infrared that, to us, will look dark,” Pearce said.
VLNComm is also looking into Li-Fi applications beyond network connectivity. For instance, indoor positioning is not very accurate using the GPS signal that Wi-Fi provides. With the LED technology, the relative distances of different lights in a room can provide more accurate indoor locations. Advanced indoor positioning can be used in manufacturing sectors in which the exact location of machinery and robots is needed to increase efficiency of production.
“The robots need to move around and need to know their exact location,” Noshad said. “For those applications, Li-Fi can provide very accurate — about [one centimeter] — positioning,” Noshad said.