Researchers there have found a way to encode a visible-frequency wireless signal in the light coming from lamps and fixtures, turning the light that surrounds us into a high-speed broadband source.
That's not to say there's anything particularly wrong with radio-frequency wi-fi, but its limited bandwidth restricts it to a certain spectrum within an already crowded field of signals. It also leaks through walls -- a benefit for signal pirates but a detriment for those who want a signal that is both secure and free of interference.
Visible-frequency wireless works by flickering all the lights in a room ever so slightly -- so slightly, in fact, that the human eye could never detect it. Incandescent and fluorescent bulbs can't flicker fast enough, so the scheme does require LED lighting, but the connection doesn't require any kind of specialized fixture, just commercial LEDs.
I read about this idea a few years ago. The article speculated on a variety of applications. One of which was paging doctors in a hosptial. Rather than using a PA system to page a person by broadcasting the page through the whole building, they could send the signal through the lights and a pager on the recipient's person could recieve the page without annoying everyone else. It seems like there are many potentially great ideas that can piggyback on this technology.
I haven't looked into it much but I wonder how data goes upstream? Are you still tied to wires or old style radio signals? It would seem that in order to send data you'd need an optical receiving device within sight of the device you're using.
Assuming this technology took off I don't see it being too far fetched for future mobile devices being "LED ready" and I don't see it as far fetched for stores to advertise via their lights. Imagine walking through a well lighted area or mall and having some sort of coupon that expires in an hour sent to your mobile device enticing you to come in to the store you just walked passed, or better yet, are about to pass. Hmm, I wonder if I can patent "short-lived coupon over wireless LED signal" ?
Anyway, what do you think this could be used for?
I think the line of sight issues would get annoying for people who are moving around. The coupon idea is good, and I think they should implement it with bluetooth.
ReplyDeleteI also wonder how slight "ever so slightly" is. I know they say LED is required, but:
http://asumag.com/mag/university_eliminating_distractions/
Fluorescent lighting flickers. It may not be discernible to most people, but the flickering can be distracting and even harmful to individuals with autism.
I wonder if ceiling fans would disrupt the light enough to make it not work?
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