STANFORD RESEARCHERS DEVELOP NEW WIRELESS TECHNOLOGY

By: Dr. Tom Macon, Ph. D.

I know some of you will say that this article isn’t related to robotics, but I see it as a component technology that could be integrated into robotic communication and control modules. Just watch the movie “Real Steel” and you surely see potential for its application.

A new technology that lets signals to be sent and received simultaneously on a single channel has been developed at Stanford. This technology allows faster, more efficient communication more than doubling existing network speed.

Radio traffic travels in a single direction at a time.  This is why pilots use the term "over" so often and why walkie‑talkie users and emergency personnel have to take turns speaking.

But now, thanks to this innovation by Stanford researchers, radios can send and receive signals at the same time.

This immediately makes them twice as fast, and it is thought that further developments will mean even faster networks in the future.

Unlike radios, cell telephone networks let users talk and listen at the same time.  To do this, they employ an expensive work‑around.  The method is less feasible for other wireless networks, including Wi‑Fi.

Three electrical engineering graduate students, Jung Il Choi, Mayank Jain and Kannan Srinivasan, worked out the approach.

They realized that wireless networks have each device take turns speaking or listening. It's like two people shouting messages at the same time. If both shout simultaneously, no one can hear anything.

The problem in two‑way simultaneous conversation with radios is that incoming signals get overwhelmed by the radio's own transmissions.  When a radio transmits, its own transmission is billions of times more powerful than the signal it gets from another radio.  You can’t hear a whisper when you are shouting.

The engineers realized that if they had the radio receiver filter out the signal from its own transmitter, then incoming signals could be heard.  The new design uses the fact that each radio knows precisely what it is transmitting at any point, making it easy to filter out that output. The process is similar to that used by noise‑canceling headphones..

Before the Stanford engineers demonstrated the approach, no one believed that sending and receiving signals simultaneously could be done.  One researcher told them their idea was too simple to work, as anything so obvious must have already been tried and shown not to work.

But the new communications technology did work, offering significant implications for future communications.  The most promising result of of sending and receiving simultaneously is that it doubles the amount of information that can be sent.  The approach promises greatly improved home and office networks, systems that pass information faster with less congestion. Just imagine the application in a command and control system for remote controlled combat 'bots of the future.

The Stanford group has a patent on the approach and is seeking to commercialize it. They are now trying to increase the strength of the transmissions and the distances over which the signals travels.  This will be necessary before the technology will be practical for use in Wi‑Fi networks.

The new technology has great promise for future networks and other applications. When new hardware and software is built to employ simultaneous two‑way transmission, the scope of the results could be limitless.

“Over and out!” will be a thing of the past. Please share your thoughts with me on its application.