Full Duplex Wireless RF Now Possible

[ionbasa]

http://www.extremetech.com/extreme/187190-full-duplex-a-fundamental-radio-tech-breakthrough-that-could-double-throughput-alleviate-the-spectrum-crunch

 

One of the most well-known constraints in RF that it is generally impossible to transmit and receive at the same time on the same frequencies because the act of transmission creates a massive amount of interference for the receiver, preventing the receiver from “hearing” the desired signal coming from the environment.

[...]

Kumu Networks is a two-year-old startup spun out of Stanford to commercialize research on self-interference cancellation technology. It has developed a way to allow for full duplex operation, which permits one set of frequencies to simultaneously transmit and receive signals, by utilizing self-interference cancellation. To put it simply, the effective efficiency of any RF-based technology operating in full duplex mode is doubled compared to half-duplex mode because it is now possible to use the full capacity of a single set of frequencies for both transmission and reception.

 

The article specifically calls out upcoming support for cellular applications, including: LTE-A and AWS. This technology essentially allows full duplex to also be usable on single cable connectors, such as  DOCSIS over Coax. Meaning that an pair of cables is no longer required for full duplex transmissions.

 

Personally, I find this technology very exciting. Hopefully 5-10 years from now this technology can be implemented to increase cellular internet connectivity. The exciting part is that this can have a broad range of applications, including: simultaneous 2 way radio (eg: HAM radio), over air transmission of interactive TV content, and even space telecommunications. But, the most relevant thing for consumers would be to see this technology come to Wi-Fi.

 

The reason I call out Wi-Fi in particular is that currently, devices have to 'take turns' transceiving data from each other (less so with MiMo). With this technology, ping and latency times should decrease. 

 

Here is a quick annotation of why wireless RF or single connector RF can't be full duplex (simultaneous receive and transmit):

Destructive interference can happen when two or more waves superimpose one another. Other types of interference include: constructive interference and reflective interference. This new technology seems to alleviate that by modulating the transmitted signal. This would be done by manipulating the frequency and wavelength ever so slightly on the fly.