Deutsche Telekom researchers break transmission speed record
Mar 02, 2012
- First 512 Gbit/s transmission over a single wavelength channel in the Telekom optical network -capacity quadrupled
- Signals sent over a distance of 734 km (Berlin - Hanover - Berlin)
- Alcatel-Lucent provides technology support - Telekom Network Production contributes network expertise
Researchers at Telekom Innovation Laboratories (T-Labs) have succeeded in realizing a 512 Gbit/s transmission over a single optical-fiber wavelength channel for the first time. This corresponds to a usable bit rate of 400 Gbit/s, or the simultaneous transmission of 77 music CDs. While the bar is higher for fiber-optic transmission in a laboratory setting, this record was set under realworld conditions in the Telekom optical network on a route of 734 km from Berlin to Hanover and back by speed of light.
Optical fiber forms the backbone of data networks, transporting vast amounts of data between nodes. The maximum bit rate in backbone networks today is 100 Gbit/s per channel. When using all of the channels of an optical fiber, much like a four-lane highway, the new process permits a throughput of up to 24.6 Tbit/s (24,600,000,000,000 bit/s) to be attained on the maximum of 48 available channels (comparable to 48 lanes) of the data highways. A collection of 3,696 CDs could thus be transferred over a single optical fiber - a strand thinner than a human hair - at the same time. With the new method, existing networks can double their current transmission capacity by merely replacing the technology in the terminal stations.
"Together with our technology partner Alcatel-Lucent and the experts at Telekom Network Production, we are very proud of having attained this tremendous transmission performance over the Internet under real-world conditions," said T-Labs Manager Heinrich Arnold. "With them, we have successfully developed an innovative method by which the transmission capacity of optical fiber can be increased significantly in network operation."
For technology experts:
The Telekom OSIRIS (Optically Supported IP Router Interfaces) research project realized transmission at a speed of 512 Gbit/s (400 Gbit/s usable bit rate) on a 100 GHz wavelength channel over a distance of 734 km, thus demonstrating a spectral sensitivity of 5 bits/s/Hz in the Deutsche Telekom network.
This tremendous transmission performance was reached using innovative transmission technology with two carrier frequencies, two polarization planes, 16-QAM quadrature amplitude modulation and digital offline signal processing for the equalization of fiber influences with soft-FEC forward error correction decoding in the receiver.
The WDM transmission link consisted of a total of 14 standard single-mode fiber sections with dispersion compensation as required for the neighboring conventional 10 Gbit/s channels.
The high optical input powers of the conventional 10 Gbit/s channels and the dispersion compensation in the fiber sections interfere with the innovative transmission technology due to nonlinearities, including self-phase modulation by the higher input power and cross-phase modulation by the adjacent channels. Despite these worst-case conditions, it was possible to demonstrate the transfer of the innovative high-speed signal simultaneously with conventional 10 Gbit/s signals in adjacent channels in an existing system. This points toward a migration path which would allow the multiplication of transmission capacities to handle the rapid increase of data traffic over networks without having to lay new cables.
About Deutsche Telekom
Deutsche Telekom is one of the world’s leading integrated telecommunications companies with over 129 million mobile customers, 34 million fixed-network lines and approximately 17 million broadband lines (as of December 31, 2011). The Group provides products and services for the fixed network, mobile communications, the Internet and IPTV for consumers, and ICT solutions for business customers and corporate customers. Deutsche Telekom is present in around 50 countries and has over 235,000 employees worldwide. The Group generated revenues of EUR 58.7 billion in the 2011 financial year - more than half of it outside Germany (as of December 31, 2011).
About Telekom Innovation Laboratories
Telekom Innovation Laboratories (Labs) are the central research and innovation (R&I) unit of Deutsche Telekom. Their mission is to work closely with Telekom's operating units by offering new ideas and support for the group when it comes to developing and rolling out innovative products, services and infrastructures for Telekom's growth areas. With sites in Berlin, Darmstadt and Bonn (Germany), as well as Beer Sheva, Tel Aviv (Israel) and Los Altos (USA), the Labs focus on midterm topics and technologies for current differentiation and launch of new business. Linking their R&I activities with industry partners, start-ups, as well as numerous universities and research institutions worldwide ensures a close tie between the Labs and the research community.www.laboratories.telekom.com