Researchers Successfully Set New Record for 400G Ultra-long-haul Transmission based on 128.8-GBaud WDM Signals Over 10,130- and 6,078-Kilometer TeraWaveTM Fiber Links

25 June 2015, Shenzhen, China – ZTE Corporation (0763.HK / 000063.SZ), a major international provider of telecommunications, enterprise and consumer technology solutions for the Mobile Internet and OFS today announced a record-setting 400G ultra-long-haul high-speed transmission result, successfully transmitting record 128.8-GBaud wavelength division multiplexing (WDM) QPSK signals over 10,130- and 6,078-kilometer terrestrial fiber links. These transmission results, once again, set a benchmark for the global optical networking industry and support the next-generation transport standard to cope with the exponential growth of IP traffic.

The successful test demonstrated the coherent transmission system with the highest electrical time division multiplexing (ETDM)-based symbol rate of 128.8-GBaud over record breaking distances, in which the single-carrier 515.2-Gb/s polarization division multiplexing (PDM)-QPSK/9-QAM signals were transmitted over 10,130km/6,078km, respectively, over 100km spans of OFS TeraWave™ optical fiber featuring optimized effective area and low loss. It was the highest ETDM-based symbol rate reported so far, and the longest WDM transmission distance of single-carrier 400G signals with terrestrial span lengths (100km). For the first time, the 515.2-Gb/s single-carrier PDM-QPSK signals in 200-GHz-grid are successfully transmitted over distances over10,000km in a terrestrial transmission environment. Researchers have also demonstrated the transmission of single carrier 128.8-GBaud filtered QPSK signals in 100-GHz-grid over 6,078km, which has the line SE of 5.152b/s/Hz.

This result sets a new record for 400G transmission in both symbol rate and distance. The milestone, published recently on Optics Express (OSA), surpasses the record last year of 110 GBaud over 3000 km transmission distance of 400G set by the same group from ZTE.

According to Dr. Jianjun Yu, the Chief Scientist on high-speed optical transmission at ZTE and OSA Fellow, “400G transmission on a single optical carrier emerged as an attractive solution since it would offer benefits in terms of system complexity. Namely, the employment of the highest feasible electronic multiplexing rates with a minimum number of channel subcarriers reduces the number of deployed optical components, which typically dominates the transponder cost. ZTE has been relentless in pushing forward-looking research and development on the single carrier 400G transmissions, and we have solved most of key technologies for this 400G product.”

According to Robert Lingle, Jr., Director of Systems & Technology Strategy at OFS, “Splicing and cable loss data on deployed TeraWave fiber in the field has proven the practicality of large effective area fibers. The use of low loss, large area fiber is now widely considered to be a key tactic for improving reach and spectral efficiency with advanced modulation formats in coherent transport, in conjunction with both erbium and Raman amplifiers.”

ZTE has long been committed to R&D in 100G and 400G/1T technologies, as well as their applications. Until now, ZTE has provided several key innovations in this field. In 2010, ZTE was the first to release an overall 100G bearing solution. It provides 100G products covering switch, router, and WDM/OTN, as well as end-to-end solutions from edge layer to core layer for customers. ZTE was also the first equipment manufacturer to realize single-channel 11.2Tb/s transmission over 640km, in 2011. ZTE accomplished 24Tb/s (24x1.3Tb/s) WDM signal transmission in the same year, which was the world's first WDM system in terabit/s. In July 2011, ZTE launched the first 1Tb/s DWDM prototype system and experiment results at the OECC.

In 2012, ZTE released a 400G/1T DWDM prototype with seven solutions designed for various network applications. In February 2012, ZTE with Deutsche Telekom successfully completed 2450km on-site ultra-long-distance hybrid transmission of 100G/400G/1T signals in Germany, setting a record of transmission distance of high-speed signal hybrid transmission in the industry.

In 2013, ZTE completed data signaling at speeds of 400Gb/s over a distance of more than 5,000km, through 25 ROADM nodes without an electrical repeater.

In 2014, ZTE achieved 20 DWDM channels of 400Gb/s single-carrier PDM-QPSK signals to successfully transmit up to 3600km in standard single-mode fiber when the spectrum efficiency is improved to 4b/s/Hz.

In 100G and 400G/1T field, ZTE has submitted dozens of patent proposals, covering optical modulator, framer, chip, and algorithms. ZTE has successfully deployed commercial networks and trials in 100G and beyond 100G with the mainstream operators in West Europe, East Europe, Asia Pacific, and China. It has become a leading global innovator developing high-speed optical communication technology.

OFS pioneered the development and commercialization of large effective area, low loss fibers for coherent transmission. The first 400G experiments in the industry were conducted on pre-production TeraWave fiber, published at major conferences in 2010. TeraWave optical fiber was first sold into a major network in 2013.