Fujitsu Limited, Nippon Telegraph and Telephone Corporation and NEC Corporation will join their R&D forces toward making a 400Gbps/channel-class digital coherent optical transmissions technology.
Bringing together the technological capabilities that have enabled the commercialization of 100Gbps-class optical transmissions methods, the companies will work to further enhance the performance and functionality of the digital coherent optical transmissions method, a key technology in optical transmissions. This R&D initiative was commissioned and is sponsored by Japan's Ministry of Internal Affairs and Communications (MIC) as part of the "Research and Development Project for the Ultra-high Speed and Green Photonic Networks" program.
"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," noted industry analyst Dana Cooperson, VP Network Infrastructure, 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 joint research is expected to enable ultra-high-speed 400Gbps-class optical transmissions through the use of dual-polarization quadrature phase shift keying (DP-QPSK), which is currently used in 100Gbps transmissions, together with dual-polarization 16 quadrature amplitude modulation (DP-16QAM), which takes advantage of an even greater number of quadrature carriers. By incorporating these modulation techniques into a high-density 60-channel fiber, the technology will be able to bring about the world's highest capacity optical networks capable of 24Tbps/fiber-class transmissions. In addition, to cut down on power consumption, long-haul transmission technology that can lead to reductions in the number of devices is required.
In light of this, the companies aim to provide the world's first compensation technology for nonlinear optical effects within an optical fiber - the primary limiting factor standing in the way of long-distance transmission of multiple quadrature modulated signals. These effects are described as a phenomenon in which the optical fiber's refractive index changes in response to the light's intensity.
When employed together with enhanced-performance versions of existing compensation technologies for chromatic dispersion (a phenomenon in which different wavelengths are transmitted at different speeds within an optical fiber) and polarization mode dispersion (a phenomenon that causes differences in transmission delay times within optical fibers due to polarization), the new technology will achieve longer transmission distances. Furthermore, the companies will pursue the implementation of adaptive modulation/demodulation technology that can employ a host of modulation techniques depending on the transmission route using a single hardware device, thereby leading to the construction of flexible network architecture.
Going forward, the companies will work until 2014 to address the aforementioned technological challenges throughout the term of the R&D project.