LED lights point shoppers in the right directionJanuary 26, 2012
Looking for an item in a large department store or mall can be like searching for a needle in a haystack, but that could change thanks to a hybrid location-identification system that uses radio frequency transmitters and overhead LED lights, suggested by a team of researchers from Penn State and Hallym University in South Korea.
"LED lights are becoming the norm," said Mohsen Kavehrad, W. L. Weiss Chair Professor of Electrical Engineering and director of the Center for Information and Communications Technology Research at Penn State. "The same lights that brighten a room can also provide locational information."
To locate an item in a mall, the system would not need to transfer large amounts of data. Kavehrad and his team envision large stores or malls with overhead LED light fixtures, each assigned with a location code. At the entrance, a computer that is accessible via keyboard or even telephone would contain a database of all the items available. Shortly after a query, the location or locations of the desired item would appear.
"The human eye can't see beyond 15 on and offs of a light per second," said Kavehrad. "We can get kilobytes and megabytes of information in very rapid blinking of the LEDs," he told attendees at the SPIE Photonics West 2012 conference today in San Francisco.
But LED-transmitted locational information alone will not work because light does not transmit through walls. Kavehrad, working with Zhou Zhou, graduate student in electrical engineering, Penn State, designed a hybrid LiFi system using a Zigbee multihop wireless network with the LEDs.
ZigBee is an engineering specification designed for small, low-power digital radio frequency applications requiring short-range wireless transfer of data at relatively low rates. ZigBee applications usually require a low data rate, long battery life, and secure networking.
While a ceiling light can have communications with anything placed beneath its area, light cannot travel through walls, so a hybrid system using light and RF became the practical solution.
The system consists of the location-tagged LEDs and combination photodiode and Zigbee receiver merchandise tags. The request for an item goes from the computer through the many jumps of short radio frequency receivers and transmitters placed throughout the mall. The RF/photodiode tag on the merchandise sought, reads its location from the overhead LED and sends the information back through the wireless network to the computer.
Even when merchandise is moved from room to room, the accurate location remains available because a different LED overhead light with a different location code signals the tag.
While ideal for shopping applications, this hybrid model is also useful in other situations. LED-transmitted information is useful in places like hospitals, where radio frequency signals can interfere with equipment.
Modern Geographic Positioning Systems, such as those in cell phones, can easily locate people outside, but they do not work within buildings. A hybrid system in a high-rise office building, for example, could not only tell the system someone was in the building, but could identify the floor where the person was at that time. In museums or hospitals, navigation systems could guide people through large buildings by reading the final destination signal from a hand-carried photodiode device and initializing lights or other indicators to show the proper path.
Kavehrad notes that Zigbee devices are designed to be inexpensive, as are the photodiodes also required for the system. Not every identical item would need a tag and the tags are reusable.
Also working on this project were Yong Up Lee, professor of electronics,
Hallym University, Chuncheon, Korea, currently at Penn State on sabbatical, and
Sungkeun Baang and Joohyeon Park, masters degree students at Hallym
- Brain wiring a no-brainer? Scans reveal astonishingly simple 3D grid structure, 8 comments
- Researchers find simple and cheap way to mass-produce graphene nanosheets, 22 comments
- Huge tornadoes discovered on the Sun, 9 comments
- Modified microbes turn carbon dioxide to liquid fuel, 42 comments
- 'Impossible' problem solved after non-invasive brain stimulation, 13 comments
- Wireless optical transmission key to secure, safe and rapid indoor communications, Jan 27, 2010 0
- Ceiling lights in Minn. send coded Internet data, Dec 27, 2010 0
- Siemens Sets New Record for Wireless Data Transfer using White LEDs, Jan 21, 2010 0
- From the desk lamp to the desktop?, Mar 09, 2010 0
- RF remote control is a superior alternative to infrared control, Mar 04, 2009 0
- Measuring water pressure differential in a pvc
19 hours ago I'm having problems with our pressure measurements on a pretty basic PVC water flow system. I drew up the general design in paint and attached it so you can have a visual of what i'm talking about....
- Flow through orifice?
20 hours ago Hallo, How to calculate the air flow (volume flow in m3/s) through an orifice of diameter ∅ 1mm, 1.2 mm and 1.5 and length 1mm? The air at room temperature is sampled through the orifice from...
- Pneumatic circuit.
21 hours ago Hey guys, Ive designed a pneumatic circuit for ---Quote--- The part concerned is an aerospace semi structural component. At 30 kilos, the new composite part is a third of the weight of...
- Frequency and period question?
Apr 01, 2012 I was wondering that the annoying buzzing sound from a mosquito is produced when it flaps its wongs at an average rate of 600 flaps per second. a) what is the frequency of the sound waves? b) what...
- How could the frequency of a guy wire be
Apr 01, 2012 I need to find the tension in guy wires so decided to go down the route of using the frequency to do so but don't know how i would go about doing so. Would anybody have any advice or help to get me...
- Book that would give an intro into engineering
Apr 01, 2012 Is there a general book that would give me an introduction to the general engineering disciplines? I don't know anything about engineering, but it looks interesting and I would like to see how much...
- More from Physics Forums - General Engineering
More news stories
(AP) -- Visa Inc. has dropped the card processor involved in a massive data breach from its registry of providers that meet data security standards.
18 minutes ago | not rated yet | 0
Cash prizes for getting to campus late or leaving early? Even Stanford University's hard-working employees and students may be tempted to participate in a new study.
8 minutes ago | not rated yet | 0
(AP) -- The sidewalk lanes for the digitally distracted may be a joke but officials in Philadelphia want the public to know the issue is no laughing matter.
16 minutes ago | not rated yet | 0
The National Archives opened a treasure trove to genealogists and historians on Monday, releasing the 1940 national census in its entirety -- and doing so for the first time online.
1 hour ago | not rated yet | 0
As computer scientists this year celebrate the 100th anniversary of the birth of the mathematical genius Alan Turing, who set out the basis for digital computing in the 1930s to anticipate the electronic age, they still quest ...
1 hour ago | 4.5 / 5 (2) | 1 |
Once again, science and anthropology have teamed up to solve questions concerning the fascinating, brilliantly hued pigment known as Maya Blue. Impervious to the effects of chemical or physical weathering, the pigment was ...
A series of global warming events called hyperthermals that occurred more than 50 million years ago had a similar origin to a much larger hyperthermal of the period, the Pelaeocene-Eocene Thermal Maximum (PETM), ...
The Earth's crust beneath the Mississippi Delta sinks at a much slower rate than what had been assumed.
Scientists from the University of Liverpool are working with computer modelling specialists in India to predict areas of the country that are at most risk of malaria outbreaks, following changes in monsoon rainfall.
Pediatric surgeons can lower health care costs if they remove a young patient's perforated appendix sooner rather than later, according to new study results published in the April issue of the Journal of the American College of ...
Researchers at Carlos III University of Madrid and the University of Zaragoza theoretically predict, in a scientific study, that contact networks have no influence on cooperation among individuals.