History
The history of Visible Light Communications (VLC) dates back to 1880 when Scottish born Canadian Alexander Graham Bell demonstrated the Photophone which transmitted speech on modulated sunlight over several hundred meters. It is interesting to note that this actually pre-dates the transmission of speech via radio.
More recently the Nakagawa Laboratory, in Keio University, Japan began work in 2003 using LEDs to transmit data by visible light. Since then there have been numerous research activities focussed on VLC. The notable research activities being Smart Lighting Engineering Centre, Omega Project, COWA, ByteLight, Inc.D-Light Project, UC-Light Centre and work at Oxford University.
Back in 2006, researchers from CICTR at Penn State proposed a combination of power line communication (PLC) and white light LED to provide broadband access for indoor applications. This research suggested that VLC could be deployed as a perfect last-mile solution in future.
In January 2010 a team of researchers from Siemens and Fraunhofer Institute for Telecommunications (Heinrich Hertz Institute in Berlin) demonstrated transmission at 500 Mbit/s with a white LED over a distance of 5 metres (16 ft), and 100 Mbit/s over longer distance using five LEDs.
The VLC standardization process is conducted within IEEE Wireless Personal Area Networks working group (802.15).
In December 2010 St. Cloud, Minnesota was the first to commercially deploy this technology.
In July 2011 a live demonstration of high definition video being transmitted from a standard LED lamp was shown at TED Global.
Recently, VLC-based indoor positioning system has become an attractive topic. Publications have been coming from Nakagawa Laboratory, COWA at Penn State and other researchers around the world.
Read more about this topic: Visible Light Communication
Famous quotes containing the word history:
“In nature, all is useful, all is beautiful. It is therefore beautiful, because it is alive, moving, reproductive; it is therefore useful, because it is symmetrical and fair. Beauty will not come at the call of a legislature, nor will it repeat in England or America its history in Greece. It will come, as always, unannounced, and spring up between the feet of brave and earnest men.”
—Ralph Waldo Emerson (1803–1882)
“When the landscape buckles and jerks around, when a dust column of debris rises from the collapse of a block of buildings on bodies that could have been your own, when the staves of history fall awry and the barrel of time bursts apart, some turn to prayer, some to poetry: words in the memory, a stained book carried close to the body, the notebook scribbled by hand—a center of gravity.”
—Adrienne Rich (b. 1929)
“The history of his present majesty, is a history of unremitting injuries and usurpations ... all of which have in direct object the establishment of an absolute tyranny over these states. To prove this, let facts be submitted to a candid world, for the truth of which we pledge a faith yet unsullied by falsehood.”
—Thomas Jefferson (1743–1826)