A Case for Visible Light Communication

Mobile phones are the most familiar example, but wireless communication has become a commonplace part of our surroundings. In the past, the telephone was typically a single device in the living room, which made it somewhat inconvenient to use. The radio waves used by mobile phones travel from towers several kilometers away, penetrate our homes, and reach our hands. Because we are connected by these invisible threads, our exact location remains unknown. However, as mobile phones have become this advanced, this drawback has become a significant problem. When there's an accident, people call 110 (police) or 119 (fire/ambulance). These days, most of these calls are made from mobile phones. This poses a major problem for the police and fire departments responding to emergencies. With a landline, the location can be identified from the phone number, but this is not possible with a mobile phone. A conversation like, Police: "Which building are you in?" Caller: "I'm in a building around Hibiya," is not helpful. Moreover, pinpointing the source of the radio signal is an extremely difficult task. So, I came up with an idea: a method to constantly embed on-off location information into lighting fixtures and emergency lights. This information can be received by a mobile phone's camera, and the location data can then be sent to 110 or 119 using the phone's radio waves. The on-off information flickers so rapidly that it is not harmful to the eyes. And since the information is received from visible light, your exact location can be accurately conveyed to the other party. It can send not only details like "Corridor Z on the Yth floor of Building XX," but even a map of the building centered on your current location. This would allow emergency services to rush to the scene with confidence. Furthermore, it can be used for management in buildings and factories, and in the future, for mobile robots. I call this type of optical communication "ubiquitous optical communication" and am calling on everyone to join the Visible Light Communications Consortium. Currently, 13 companies, including NEC, Matsushita Electric Works, Agilent, and KDDI, have joined. This will make it easy to obtain location information from nearby lighting and emergency lights, and I would be grateful if you could share any interesting applications you can think of.