Kumu's full duplex technology makes inroads with operators

Kumu Networks, a startup that was founded around 2012 by a team of Stanford University professors and Ph.D graduates, is gaining momentum, with operator trials moving from the lab to the field.

The problem that Kumu aims to solve has to do with the fact that radios cannot transmit and receive at the same time on the same channel, requiring FDD or TD duplexing. Kumu's self-interference cancellation technology isolates the receiver from the transmitter, allowing radios to transmit and receive simultaneously on the same frequency.

Kumu signed a memorandum of understanding with SK Telecom at Mobile World Congress 2015 in Barcelona, Spain, where Telefónica also highlighted Kumu's full-duplex demo at its booth, attracting a lot of attention in that high-profile setting. Last month, SK Telecom used Kumu's technology to demonstrate a robotic traffic officer at the World IT Show 2015 in Seoul. The robot demo used Kumu's In Band Full Duplex (IBFD) technology, which is being positioned as a pre-5G technology that will significantly enhance spectral efficiency.

Kumu also is among the partners in Deutsche Telekom's "5G:haus" innovation laboratory, which involves research organizations, traditional vendors and startups working on the development and standardization of 5G technology.

With operators, "we are engaged to the point where they are sufficiently comfortable with our technology to showcase it, talk about it, and we are going through a variety of trials," Joel Brand, Kumu's vice president of product management, told FierceWirelessTech.

"Everyone wants to move it from the research" to product stage, he said. "At the end of the day, they want to know how this behaves when a person walks in front of the antenna," because all these things affect the behavior of RF. "That's the focus of these trials, and these trials are moving the technology from the lab environment to the field," he said. "That's kind of where we are in terms of operator interaction."

Gaining the confidence of these high-profile operators is a feat unto itself. Yet the concept behind the technology is fundamentally simple, Brand said. When a normal radio transmits, it makes so much noise, it can't receive the signal from the other end--"it's like trying to listen to a whisper while screaming at the top of your lungs," and that's the case across the spectrum.

What Kumu succeeds in doing is putting a device in front of the antenna and canceling the self-interference. "The concept is, let's connect something between your mouth and your ear such that when you scream, you don't hear yourself," he said. "That's what we've done. We're connecting a device between the transmitter of the radio and the receiver of the radio, and we silence the transmitted signal to the 'ear' of the radio," he said. Once you silence the "noise," you can hear everything else.

When full duplexing transmission is achieved, "that changes fundamentally" the way the world is thinking about spectrum allocation, he said. At a bare minimum, Kumu says it can double capacity.

For more:
- see this EE Times article

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