Nokia Bell Labs, Deutsche Telekom T-Labs and Technical University of Munich achieve speeds of 1 Tb per second in groundbreaking optical technology trial

Press Release

• In jointly conducted research of optical systems, Nokia Bell Labs, Deutsche Telekom T-Labs and the Technical University of Munich achieved a 1 Terabit-per-second transmission rate over optical fiber
• Probabilistic Constellation Shaping provides greater flexibility and performance to enable optical networks to operate closer to the Shannon limit to meet growing consumer and business data demands

Breakthrough will allow telecommunication operators and enterprises to further maximize the distance and capacity of high speed data transmission in optical metro and core networks

September 16, 2016

Duesseldorf, Germany - Nokia Bell Labs, Deutsche Telekom T-Labs and the Technical University of Munich have achieved unprecedented transmission capacity and spectral efficiency in an optical communications field trial with a new modulation technique. The breakthrough research could extend the capability of optical networks to meet surging data traffic demands.

The demonstration shows that the flexibility and performance of optical networks can be maximized when adjustable transmission rates are dynamically adapted to channel conditions and traffic demands. As part of the Safe and Secure European Routing (SASER) project, the experiment over a deployed optical fiber network of Deutsche Telekom achieved a net 1 Terabit transmission rate. This is close to the theoretical maximum information transfer rate of that channel and thus approaching the Shannon Limit of the fiber link.

The Shannon Limit was discovered in 1948 by Claude Shannon, Bell Labs pioneer and the "father of information theory."

The trial of the novel modulation approach, known as Probabilistic Constellation Shaping (PCS), uses quadrature amplitude modulation (QAM) formats to achieve higher transmission capacity over a given channel to significantly improve the spectral efficiency of optical communications.

PCS modifies the probability with which constellation points - the alphabet of the transmission - are used. Traditionally, all constellation points are used with the same frequency. 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. This allows the transmission rate to be tailored to ideally fit the transmission channel, delivering up to 30 percent greater reach.