September 23, 2016
Nokia Bell Labs, Deutsche Telekom T-Labs, and the Technical University of Munich are demonstrating Probabilistic Constellation Shaping (PCS), a technique that delivers 1Tbps speeds over fiber — much faster than Google Fiber’s 1Gbps. Nokia Networks reports that it’s tested 1Tbps “on a round trip between the German cities of Stuttgart and Darmstadt, as well as between Stuttgart and Nuremberg,” and also achieved 0.8Tbps between Stuttgart and Berlin. This is only the latest effort to bring terabit networks to fruition.
ZDNet reports that, also recently, researchers at University College London were able to attain speeds of 1.25Tbps, which is capable of downloading the entire “Game of Thrones” series in HD in one second. Although video bingeing doesn’t require that capacity, “terabit-speed networks will meet growing demand for higher-capacity core networks” and “present a major leap forward over current Internet-backbone network limits of 40Gbps to 100Gbps.”
Nokia describes PCS as using “quadrature amplitude modulation (QAM) formats to achieve higher transmission capacity over a given channel to significantly improve the spectral efficiency of optical communications,” adding that, “PCS cleverly uses constellation points with high amplitude less frequently than those with lesser amplitude to transmit signals that, on average, are more resilient to noise and other impairments.”
The result is that the transmission rate can be “tailored to ideally fit the transmission channel, delivering up to 30 percent greater reach.”
As a result, says Nokia Bell Labs, PCS will “allow operators and enterprises to improve the distance and capacity of high-speed data transmissions in optical metro and core networks.” The technology may also “eventually be useful for backhaul networks for fiber-to-the-home connections,” but not currently for wireless networks.
“The success of the close collaboration with Nokia Bell Labs, who further developed the technology, and Deutsche Telekom T-Labs, who tested it under real conditions, is satisfying confirmation that TUM engineering is a label of outstanding quality,” said Technical University of Munich professor Gerhard Kramer.