RESUMO
The total capacity of optical submarine cable systems as a global communication infrastructure must be continuously enlarged. Multi-core fibers (MCFs) have been studied as methods to maximize the total cable capacity under electrical power and cable space limitations. In particular, standard cladding MCFs, which are expected to have high productivity and mechanical reliability, are attractive for early deployment in submarine cable systems. In this paper, we demonstrate high-capacity trans-Pacific class transmission using standard cladding uncoupled 4-core fibers, achieving a transmission capacity of 55.94 Tbit/s over 12,040 km. In addition, based on the results of this and our previous coupled MCF transmission experiments, we summarize the characteristics of coupled and uncoupled MCFs applied to optical submarine cable systems.
RESUMO
Ultra-dense spatial-division multiplexing (SDM) is achieved by mode multiplexed technique with multiple cores in a single fiber, namely few-mode multi-core fiber. Using a 9.8-km six-mode nineteen-core fiber, we demonstrate an ultra-dense SDM transmission of 16-channels wavelength-division-multiplexed (WDM) dual-polarization quadrature phase shift keying signals, achieving a record spatial multiplicity of 114. With the help of ultra-dense Super-Nyquist WDM techniques in the 4.5-THz bandwidth of the full C-band, we demonstrate 2.05 Pbit/s transmission over 9.8-km six-mode nineteen-core fibers. In this experiment, the highest aggregate spectral efficiency of 456 bit/s/Hz is achieved.
RESUMO
The feasibility of software-defined optical networking (SDON) for a practical application critically depends on scalability of centralized control performance. The paper, highly scalable routing and wavelength assignment (RWA) algorithms are investigated on an OpenFlow-based SDON testbed for proof-of-concept demonstration. Efficient RWA algorithms are proposed to achieve high performance in achieving network capacity with reduced computation cost, which is a significant attribute in a scalable centralized-control SDON. The proposed heuristic RWA algorithms differ in the orders of request processes and in the procedures of routing table updates. Combined in a shortest-path-based routing algorithm, a hottest-request-first processing policy that considers demand intensity and end-to-end distance information offers both the highest throughput of networks and acceptable computation scalability. We further investigate trade-off relationship between network throughput and computation complexity in routing table update procedure by a simulation study.