FREMONT, USA: Opnext Inc., a global leader in high speed optical communications technology, has demonstrated a single wavelength, real-time coherent 127G PM-QPSK (Polarization Multiplexed Quadrature Phase Shift Keying) modem trialed on an AT&T ultra long haul link between Louisiana and Florida.
The demonstration also included Opnext’s fully IEEE 802.3ba standards-compliant CFP MSA client optical modules which are fully interoperable with 100 GbE interfaces on IP routers.
Opnext’s plug and play technology allows carriers to upgrade their existing line systems to 100 Gbps without having to strand capacity or light new fibers. It eliminates the need for external dispersion compensation which reduces cost, minimizes IP latency and allows for deployment over older installed fiber with poor transmission characteristics.
“Most of the 100G coherent trials announced in the past are not real time solutions and are only testing the optics; the data is acquired on a digitizing oscilloscope and coherent DSP post-processing is offloaded to a PC,” said Andrew Schmitt, Directing Analyst of Optical at Infonetics Research. “Opnext's trial is different because they are demonstrating a real-time solution implemented in hardware for the toughest part of the 100G coherent transport problem.”
“Bandwidth requirements have increased significantly faster than capacity in recent years and faster transmission speeds will provide carriers with the ability to move more data over essentially the same infrastructure,” said Mike Chan, President of the Opnext’s Subsystems business unit.
“The latest consumer and business applications such as HD video-on-demand, user-generated video, video gaming, video teleconferencing and software as a service will continue to drive the need for greater bandwidth. Ever faster internet access speeds enabled by 4th generation wireless and Fiber-to-the-Home (FTTH) technologies push more traffic into carrier backbone networks, where Opnext is in an excellent position to benefit from the next wave of bandwidth investments.”
The real-time optical Modulator Demodulator (MODEM) operates at 127 Gbps with a PM-QPSK modulation format described in the Optical Internetworking Forum framework document on Ultra Long Haul 100 Gbps transmission.
The system is designed to carry an industry leading 20 percent overhead Forward Error Correction (FEC) required for ultra long haul and submarine transmission distance and to carry 100 GbE payload transparently mapped into an ITU OTU4 payload. The design is also extremely tolerant to filtering allowing for metro/regional networking with 10 or more cascaded ROADMs at 50 GHz channel spacing.