http://www.bit-tech.net/news/2008/10/08/wifi-competitor-uses-visible-light/1?tcs=nlWiFi competitor uses visible light
Author: Gareth HalfacreePublished: 8th October 2008
If you're tired of unreliable WiFi connections but still want to do your browsing sans wires, the common light fitting might offer some hope for the future.
According to Cellular News
, a team at Boston University's College of Engineering is currently working on the ability to use LED lighting as a data communication channel, removing the need for a tethering wire while cleaning up the radio-frequency spectrum at the same time.
Professor Thomas Little paints a picture of a world where “your computer, iPhone, TV, radio and thermostat could all communicate with you when you walked in a room just by flipping the wall light switch and without the usual cluster of wires,” - so far, so WiFi. Where the project differs is in the use of visible light rather than radio waves: Little describes the system as “an LED-based communications network that also provides light - all over existing power lines with low power consumption, high reliability and no electromagnetic interference. Ultimately, the system is expected to be applicable from existing illumination devices, like swapping light bulbs for LEDs.”
While the project could feasibly work, there's a certain amount of assumption involved here: firstly, that we “switch from incandescent and compact florescent lighting to LEDs in the coming years” as a ubiquitous source of LED-based lighting is necessary for the system to work; secondly, that we're happy to have said LED lights turned on during the day.
While the speeds currently offered by the system – a projected 10Mb/s for the early generations – aren't anything to get excited about it's a system that certainly shows promise. Whether it would ever tempt anyone away from the now nearly ubiquitous radio-frequency based wireless networking technologies will remain to be seen – although the increased privacy available by simply drawing your curtains might have the paranoiacs enjoying wireless networking for the first time.
Would you be tempted by visible-light networking, or is wireless networking already solved by current RF-based technologies?
Radio is still line of sight until you get into about 6-meter and greater bands.
My router's wifi signal passes through walls. Just about every single consumer radio technology (at least in my apartment anyway) is not line of sight.
WiFi and other 2.4GHz signals (Bluetooth) also pass through your head...not to mention any RF technology that utilizes electromagnetic frequencies.
I would definitely advocate this new technology over the current RF standard. There are just one too many cancer patients out there who have faced the effects of constant electromagnetic interference. By using light waves as an alternative, this would not only reduce the effects of electromagnetic frequencies on the body, but it would also clear up the clutter of the current RF situation - all while providing better signal quality to current widespread RF technologies such as cell phones and short range wireless technologies.