Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford researchers develop wireless technology for faster, more efficient communication networks

15.02.2011
A new technology that allows wireless signals to be sent and received simultaneously on a single channel has been developed by Stanford researchers. Their research could help build faster, more efficient communication networks, at least doubling the speed of existing networks.

"Wireless communication is a one-way street. Over."

Radio traffic can flow in only one direction at a time on a specific frequency, hence the frequent use of "over" by pilots and air traffic controllers, walkie-talkie users and emergency personnel as they take turns speaking.

But now, Stanford researchers have developed the first wireless radios that can send and receive signals at the same time.

This immediately makes them twice as fast as existing technology, and with further tweaking will likely lead to even faster and more efficient networks in the future.

"Textbooks say you can't do it," said Philip Levis, assistant professor of computer science and of electrical engineering. "The new system completely reworks our assumptions about how wireless networks can be designed," he said.

Cell phone networks allow users to talk and listen simultaneously, but they use a work-around that is expensive and requires careful planning, making the technique less feasible for other wireless networks, including Wi-Fi.

Sparked from a simple idea
A trio of electrical engineering graduate students, Jung Il Choi, Mayank Jain and Kannan Srinivasan, began working on a new approach when they came up with a seemingly simple idea. What if radios could do the same thing our brains do when we listen and talk simultaneously: screen out the sound of our own voice?

In most wireless networks, each device has to take turns speaking or listening. "It's like two people shouting messages to each other at the same time," said Levis. "If both people are shouting at the same time, neither of them will hear the other."

It took the students several months to figure out how to build the new radio, with help from Levis and Sachin Katti, assistant professor of computer science and of electrical engineering.

Their main roadblock to two-way simultaneous conversation was this: Incoming signals are overwhelmed by the radio's own transmissions, making it impossible to talk and listen at the same time.

"When a radio is transmitting, its own transmission is millions, billions of times stronger than anything else it might hear [from another radio]," Levis said. "It's trying to hear a whisper while you yourself are shouting."

But, the researchers realized, if a radio receiver could filter out the signal from its own transmitter, weak incoming signals could be heard. "You can make it so you don't hear your own shout and you can hear someone else's whisper," Levis said.

Their setup takes advantage of the fact that each radio knows exactly what it's transmitting, and hence what its receiver should filter out. The process is analogous to noise-canceling headphones.

When the researchers demonstrated their device last fall at MobiCom 2010, an international gathering of more than 500 of the world's top experts in mobile networking, they won the prize for best demonstration. Until then, people didn't believe sending and receiving signals simultaneously could be done, Jain said. Levis said a researcher even told the students their idea was "so simple and effective, it won't work," because something that obvious must have already been tried unsuccessfully.

Breakthrough for communications technology
But work it did, with major implications for future communications networks. The most obvious effect of sending and receiving signals simultaneously is that it instantly doubles the amount of information you can send, Levis said. That means much-improved home and office networks that are faster and less congested.

But Levis also sees the technology having larger impacts, such as overcoming a major problem with air traffic control communications. With current systems, if two aircraft try to call the control tower at the same time on the same frequency, neither will get through. Levis says these blocked transmissions have caused aircraft collisions, which the new system would help prevent.

The group has a provisional patent on the technology and is working to commercialize it. They are currently trying to increase both the strength of the transmissions and the distances over which they work. These improvements are necessary before the technology is practical for use in Wi-Fi networks.

But even more promising are the system's implications for future networks. Once hardware and software are built to take advantage of simultaneous two-way transmission, "there's no predicting the scope of the results," Levis said.

Sandeep Ravindran is a science-writing intern at the Stanford News Service.

Louis Bergeron | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Information Technology:

nachricht Deep Learning predicts hematopoietic stem cell development
21.02.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Sensors embedded in sports equipment could provide real-time analytics to your smartphone
16.02.2017 | University of Illinois College of Engineering

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>