Digital coherent optical transmission technology
A next-generation optical transmission method that combines coherent reception and digital signal processing. In addition to streamlining frequency usage through modulation methods such as polarization division multiplexing and phase modulation, the technology enables significant improvements in receiver sensitivity.
 Coherent DSP
A digital signal processing (DSP) circuit used in digital coherent optical transmissions. It converts analog data into digital data and executes various signal processing.
 Adaptive modulation/demodulation
Technology that enables the efficient operation of optical network resources through improved link quality by switching to the optimal modulation/demodulation method depending on the characteristics of the optical network.
 Sub-carrier multiplexing
A method to configure a high-speed channel by densely multiplexing several wavelengths of optical signals, with hardly any gaps.
 Nyquist filtering
Filtering technology that enables to condense the signal spectral occupancy by half without compromising signal quality.
 Digital backward propagation
Technology that simultaneously converts received optical signals into digital signals, then compensates linear and nonlinear distortions in the optical fiber by virtually reversing transmission using digital signal processing.
 MSSC-LDPC (Multiple-Structured Spatially Coupled type Low-Density Parity-Check)
A unique, low-density parity-check code comprised of a regularly-arranged structure in the parity-check matrix referred to as a "multiple spatially-coupled type," which avoids factors that cause performance degradation in the parity-check matrix. (K. Sugihara, et al., OFC/NFOEC2013, OM2B.4, March 2013)
For long-haul transmission tests, there are straight-line tests and recirculation loop tests. In contrast to the loop tests, in which a relatively short length of optical fiber is looped and a signal run through the same fiber several times to make up the transmission distance, straight-line tests use optical fiber that is the same length as the transmission distance. Straight-line tests yield results that are closer to actual transmission lines.
Fujitsu is the leading Japanese information and communication technology (ICT) company offering a full range of technology products, solutions and services. Approximately 162,000 Fujitsu people support customers in more than 100 countries. We use our experience and the power of ICT to shape the future of society with our customers. Fujitsu Limited (TSE: 6702) reported consolidated revenues of 4.8 trillion yen (US$46 billion) for the fiscal year ended March 31, 2014. For more information, please see http://www.fujitsu.com.
NTT (Nippon Telegraph and Telephone Corporation) is the world's largest global IT and telecommunications services company. The company's roots go back over 100 years to the introduction of the telegraph in Japan and focuses today on innovation in the cloud, mobility, network and communications. The company had operating revenues of US$112 billion for the fiscal year ended March 31, 2014 and employs more than 240,000 people worldwide. The company's subsidiaries include Regional Communications Businesses: NTT EAST, NTT WEST; Mobile Communications Businesses: NTT DOCOMO; Long-Distance and International Communication Businesses: NTT Communications and Dimension Data; and Data Communication Businesses: NTT DATA. For more information, visit http://www.ntt.co.jp/index_e.html.
NEC Corporation is a leader in the integration of IT and network technologies that benefit businesses and people around the world. By providing a combination of products and solutions that cross utilize the company's experience and global resources, NEC's advanced technologies meet the complex and ever-changing needs of its customers. NEC brings more than 100 years of expertise in technological innovation to empower people, businesses and society. For more information, visit NEC at http://www.nec.com.
Press ContactsPublic and Investor Relations Division
Press ContactsScience and Core Technology Laboratory Group, Public Relations
Company:Nippon Telegraph and Telephone Corporation
Press ContactsSeiichiro Toda
Press ContactsJoseph Jasper
All company or product names mentioned herein are trademarks or registered trademarks of their respective owners. Information provided in this press release is accurate at time of publication and is subject to change without advance notice.
Date: 04 September, 2014
Company: Fujitsu Limited, Nippon Telegraph and Telephone Corporation, NEC Corporation
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