Fujitsu Ltd., Nippon Telegraph and Telephone Corp. (NTT), and NEC Corp. say they will collaborate on research aimed at developing coherent-based 400-Gbps optical transmission technology. Japan's Ministry of Internal Affairs and Communications (MIC) will sponsor the effort as part of its "Research and Development Project for the Ultra-high Speed and Green Photonic Networks" program.
In addition to boosting data rates to 400 Gbps, researchers at the three firms will strive to develop technology that uses power more efficiently than current 100-Gbps technologies that rely on multi-phase modulation formats such as dual-polarization quadrature phase-shift keying (DP-QPSK) and coherent receivers. The resultant transmission technology also will be expected to promote flexibility in fiber-optic networks, including the ability to adapt to changes in data volumes and transmission distances in real time.
The companies plan to leverage both DP-QPSK and dual-polarization 16 quadrature amplitude modulation (DP-16QAM). The resulting technology should support 400 Gbps in 60 channels, for a total fiber capacity of 24 Tbps. To realize such capacity over reaches similar to those current 100-Gbps transmission technology supports, Fujitsu, NTT, and NEC plan to develop compensation technology for nonlinear effects, which will complement existing compensation techniques for chromatic dispersion and polarization-mode dispersion. Finally, engineers at the three companies will tackle an adaptive modulation/demodulation scheme that will enable systems to deploy the optimal modulation format for a given link or service.
The three companies have already collaborated on coherent-based 100-Gbps technology, including the digital coherent DSP-LSI semiconductor device most optical transponder developers are using in the first generation of 100-Gbps transponders (see, for example, "Fujitsu Optical Components announces 100-Gbps DP-QPSK transponder").
"In 2012 the supply and demand of 100G products began to converge, leading to significant growth in deployments. The demand for network connectivity will only increase. Therefore, the need for 400G solutions that provide even greater bandwidth with the lowest possible power consumption and flexible, adaptive modulation will be critical," according to Dana Cooperson, vice president, network infrastructure, at market research and consultancy firm Ovum, Inc. "Fujitsu, NTT, and NEC's collaborative efforts to meet this growing demand illustrate what's possible when key industry players work together. Carriers, enterprises, governments, and others would be wise to look closely at this solution as they evolve their networks."
The three companies hope to deliver 400-Gbps technology based on their combined efforts by 2014.
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