Quite recently, at the Consumer Electronics Show 2012, Casio demonstrated the prototype of a VLC product. Casio has been a member of the Visible Light Communications Consortium since it was initiated in 2004. In addition to fundamental research and standards development for VLC, Casio is developing applied technology for receiving signals through the use of image sensors such as complementary metal-oxide-semiconductor (CMOS) and charge-coupled-device (CCD) sensors.
Casio’s image sensor communications technology can determine the point of data transmission while simultaneously receiving many signals. The company has used its image sensor communications technology to develop the proto-type of a smartphone VLC system for consumer and commercial applications. The system flashes smartphone screens to achieve VLC. Casio demonstrated a potential social media application.
This is how the system works: When someone takes a photo with a smartphone camera, the subjects simply turn the screens of their smartphones toward the camera device to display personal information or messages in the photo. The photo-taker’s phone can receive data from up to five smartphones to add information to the photo. The information is displayed in message balloons of up to 120 characters, with customisable balloon shapes and image frames. Information such as e-mail addresses, telephone numbers and social network usernames is automatically saved on the photo-taker’s smartphone. Twitter-upload tweets the image containing the messages. The same technology can be extended to backlit ad banners and more.
Overall, the developments are quite interesting, and we could hope to see Li-Fi and other VLC technologies in the mainstream five years down the line.
However, one misconception needs to be cleared at the very outset: Li-Fi or similar technologies, for that matter, do not compete with Wi-Fi, but complement it.
“I don’t see a battle between Li-Fi and Wi-Fi,” says Dr Povey. “Cellular data does not really compete with Wi-Fi. They complement each other. I see the same position with Li-Fi. When the cellular networks became congested, we were encouraged to use Wi-Fi at home or in the office to offload the excess demand. Now Wi-Fi is getting overloaded and so for short-range high-data rate links, it seems logical to offload the excess demand to Li-Fi. Because of the exponentially growing demand for data, we have a choice—a light bulb or a cable,” he adds.
The author is a technically-qualified freelance writer, editor and hands-on mom based in Chennai