Posts Tagged ‘Edinburgh University’

Chinese Li-Fi development moves faster than in Europe

October 22, 2013

“Light Fidelity” – Li- Fi  for using light from LED’s as a data carrier instead of radio frequencies was coined at the University of Edinburgh:

PhysOrg: Li-Fi is a term referring to “light fidelity” coined by Prof. Harald Haas from the University of Edinburgh and refers to a type of visible light communication (VLC) technology that delivers a networked, mobile, high-speed communication solution. He set up a private company, PureVLC, to continue exploring the technology.

But now it seems that the Chinese have developed this technology a lot faster than Prof. Haas’ company and could be closer to commercial application than the originators.

Xinhua: 

Successful experiments by Chinese scientists have indicated the possibility of the country’s netizens getting online through signals sent by lightbulbs (LiFi), instead of WiFi.

Four computers under a one-watt LED lightbulb may connect to the Internet under the principle that light can be used as a carrier instead of traditional radio frequencies, as in WiFi, said Chi Nan, an information technology professor with Shanghai’s Fudan University, on Thursday.

A lightbulb with embedded microchips can produce data rates as fast as 150 megabits per second, which is speedier than the average broadband connection in China, said Chi, who leads a LiFi research team including scientists from the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences.

With LiFi cost-effective as well as efficient, netizens should be excited to view 10 sample LiFi kits that will be on display at the China International Industry Fair that will kick off on Nov. 5 in Shanghai.

The current wireless signal transmission equipment is expensive and low in efficiency, said Chi. 

“As for cell phones, millions of base stations have been established around the world to strengthen the signal but most of the energy is consumed on their cooling systems,” she explained. “The energy utilization rate is only 5 percent.”

Compared with base stations, the number of lightbulbs that can be used is practically limitless. Meanwhile, Chinese people are replacing the old-fashioned incandescent bulbs with LED lightbulbs at a fast pace.

“Wherever there is an LED lightbulb, there is an Internet signal,” said Chi. “Turn off the light and there is no signal.”

However, there is still a long way to go to make LiFi a commercial success.

“If the light is blocked, then the signal will be cut off,” said Chi.

More importantly, according to the scientist, the development of a series of key related pieces of technology, including light communication controls as well as microchip design and manufacturing, is still in an experimental period.

Prof. Haas and his company are not very amused and expressed some skepticism.

PhysOrg again: 

As for reactions to the report from China, a spokesperson, according to the BBC, said they thus far had not seen any evidence such as videos or photos in support of the claims. PureVLC spokesman Nikola Serafimovski said they did not know how valid was the report “without seeing more evidence.”

In 2011, Haas demonstrated how an LED bulb equipped with signal processing technology could stream a high-definition video to a computer. Haas performed the first public demonstration of visible light communications live at TED Global, where he showed an angle poise lamp fitted with an LED bulb transmitting high-definition video displayed on a screen. When he interrupted the light with his hand, the video froze and it was then restored when he removed his hand.