Fujitsu Offers Integrated 40 Gbps Wavelengths on Widely-Deployed FLASHWAVE® 7500 ROADM

Fujitsu Network Communications, a leading supplier of IT and wireline/wireless networking solutions, announced today integrated 40 Gbps transmission capabilities for its popular FLASHWAVE® 7500 Reconfigurable Optical Add/Drop Multiplexer (ROADM). Fujitsu has developed an advanced modulation scheme and per-wavelength variable dispersion compensation (VDC) to create the industry’s first fully integrated 40 Gbps ROADM solution that offers up to 1.6 terabytes of capacity and a seamless upgrade of existing 10 Gbps-based Dense Wavelength Division Multiplexer (DWDM) networks to support 40 Gbps wavelengths.

“As a leader in the photonics and metro DWDM industry, Fujitsu has applied several unique solutions and technologies to provide 40 Gbps transport on our FLASHWAVE 7500 ROADM,” said Bill Erickson, senior vice president of planning and development at Fujitsu Network Communications. “While many of our potential competitors have chosen a 40 Gbps solution that requires an external shelf and alien wavelengths to work, we believe that our fully-integrated approach offers a far more compelling and manageable option for carriers. By integrating 40 Gbps capability directly into the ROADM, we will achieve greater distance performance, while simplifying operations with fewer fiber jumpers, better performance monitoring, fewer spares, and an overall reduction in space and power.”

Three new 40 Gbps units for the FLASHWAVE 7500 ROADM offer options for multiple deployment scenarios. The 40 Gbps transponder provides a full band tunable network interface and a 40 Gbps client interface, designed primarily for interconnection of core routers. The 40 Gbps muxponder combines four 10 Gbps client interfaces into a single wavelength operating at 40 Gbps, which provides additional capacity expansion on constrained routes. The 40 Gbps regenerator unit eliminates back-to-back transponders on long spans, reducing cost and complexity. Each unit plugs directly into the existing FLASHWAVE 7500 chassis with no changes required to support 40 Gbps wavelengths across existing metro/regional DWDM networks.

Optical performance requirements such as optical signal-to-noise ratio (OSNR), chromatic dispersion, polarization mode dispersion (PMD), and spectral width become much more stringent as bit rates increase. Fujitsu has developed a number of key technologies to support 40 Gbps DWDM transmission over existing networks, including advanced modulation techniques and per-wavelength dispersion compensation. By utilizing a Return to Zero Differential Quadrature Phase Shift Keying (RZ-DQPSK) modulation scheme and per-transponder VDC, there is no need to change dispersion compensation of existing networks when upgrading to support 40 Gbps wavelengths. These technologies dramatically improve PMD tolerance and OSNR performance of DWDM networks, resulting in longer spans, fewer regeneration sites, and increased number of ROADM nodes per network.

The industry-leading FLASHWAVE 7500 ROADM is widely deployed in the RBOC and MSO markets for core network consolidation, metro/regional capacity relief, and triple-play service delivery. Based on a Wavelength Selective Switch (WSS) architecture, the FLASHWAVE 7500 ROADM can add, drop or pass-though up to 40 channels at any node with single channel granularity. Hub configurations allow up to eight-degree optical switching between multiple ring and optical (mesh) paths. The system supports network capacity to 1.6 Tbps, network sizes up to 1000 km and up to 24 OADM nodes per network.