Featured Research

from universities, journals, and other organizations

Wireless optical transmission key to secure, safe and rapid indoor communications

Date:
January 28, 2010
Source:
Penn State
Summary:
Light is better than radio waves when it comes to some wireless communications, according to a group of engineers. Optical communications systems could provide faster, more secure communications with wider bandwidth and would be suitable for restricted areas like hospitals, aircraft and factories.

Light is better than radio waves when it comes to some wireless communications, according to Penn State engineers. Optical communications systems could provide faster, more secure communications with wider bandwidth and would be suitable for restricted areas like hospitals, aircraft and factories.

Sending information via light waves either in physical light guides or wirelessly is not new, but existing wireless systems either require direct line of sight or are diffused and have low signal strength. The researchers chose to take a different approach using multi-element transmitters and multi-branch optical receivers in a quasi-diffuse configuration.

The system uses a high-powered laser diode -- a device that converts electricity into light -- as the optical transmitter and an avalanche photo diode -- a device that converts light to electricity -- as the receiver. The light bounces off the walls and is picked up by the receiver.

"Unless the walls are painted solid black, there is no need to worry about transmission within a room," said Jarir Fadlullah, graduate student in electrical engineering who presented the paper Jan. 27 at SPIE Phonotics West Conference in San Francisco, the paper will be published in the conference proceedings.

The researchers tested infrared light, but the system will also work with visible light and ultraviolet light.

"The optical system we have offers a very large bandwidth thus a very high speed," said Fadlullah. "We can send one gigabit per second or more over a gigahertz band."

The researchers, including Mohshen Kavehrad, professor of electrical engineering, think this looks like an ideal system. Radio frequency systems do not require line of sight transmission, but can pass through some substances and so present a security problem. Light, in a room without windows, will not escape the room, improving security, but also allowing the same frequencies to be used in adjacent rooms without interference. Multiple sensors could allow the light signal to pass from room to room or even from floor to floor. The system could also be set up to convert the signal to electricity, transfer it to another location and change it back to light.

"The safest security is physical layer security," said Mohshen Kavehrad. "If you first have to break into the building before you can attack the network it makes it very difficult."

He also notes that an optical system can operate in locations where radio frequency transmission would interfere with other equipment, especially in hospitals, aircraft and even some factories. Because this system is optical, it will not interfere with the radio frequency emissions of navigation equipment, medical devices or factory control systems.

Optical transmissions can transfer sensor data and unlike radio frequency communications, can also distribute high-resolution images.

"One application for this system would be wireless projection of high definition television," said Kavehrad. "Currently, two high definition broadcasts exceed the bandwidth of any radio system, but with a 1.6 gigabit per second gigabit system, two HD channels could be broadcast."

While this application in conference rooms could provide mobility for presentations, applications in aircraft and medical facilities are probably more important. Currently, wireless communications are difficult in these situations because radio frequency systems can interfere with equipment using radio frequency control or communications. An optical system can operate in the same space as a radio system without interference.

"As far as I know, these are the first set of measurements for indoor optical wireless links that show the feasibility of the highest bit rates with no line-of-sight," said Kavehrad. "No radio system had comparable ability."

The researchers will continue to test optical systems, looking at visible and ultra violet light. They also believe that light emitting diode room lighting could be incorporated into the systems to provide a blanket communications network. The researchers note that this is a very green technology.

The National Science Foundation supported this work.


Story Source:

The above story is based on materials provided by Penn State. Note: Materials may be edited for content and length.


Cite This Page:

Penn State. "Wireless optical transmission key to secure, safe and rapid indoor communications." ScienceDaily. ScienceDaily, 28 January 2010. <www.sciencedaily.com/releases/2010/01/100127211857.htm>.
Penn State. (2010, January 28). Wireless optical transmission key to secure, safe and rapid indoor communications. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2010/01/100127211857.htm
Penn State. "Wireless optical transmission key to secure, safe and rapid indoor communications." ScienceDaily. www.sciencedaily.com/releases/2010/01/100127211857.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Japan Looks To Faster Future As Bullet Train Turns 50

Japan Looks To Faster Future As Bullet Train Turns 50

Newsy (Oct. 1, 2014) Japan's bullet train turns 50 Wednesday. Here's a look at how it's changed over half a century — and the changes it's inspired globally. Video provided by Newsy
Powered by NewsLook.com
US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins