Thursday, March 22, 2018

ZTE carries 66GBaud PDM-16QAM 400Gb/s WDM signals over 6,000 km

ZTE, working in collaboration with OFS and NeoPhotonics, transmitted 66GBaud PDM-16QAM 400Gb/s WDM signals over 6,000 km on 100 km spans with the channel spacing of 75GHz.

This sets a new world record for 400G ultra-long-haul (ULH) high-speed transmission distance, according to the companies.

In this test, the 506 Gb/s PDM-16 QAM signals after probability shaping are transmitted over 6,000 km on OFS 100 km spans with the channel spacing of 75GHz. This is the longest WDM transmission distance of PDM-16QAM signals so far based on the terrestrial transmission system (100km span) with the line spectrum efficiency exceeding 5.3b/s/Hz.


The test used probability shaping coherent communication technology developed by ZTE. The low-power-consumption small-sized high-bandwidth coherent driver modulator (HB-CDM) was designed and produced by NeoPhotonics and the large-aperture low-loss OFS TeraWave fibers provided by OFS.

“Single-carrier 400G transmission has become the most attractive beyond 100G solution since it can reduce system complexity,” said Dr. Yu Jianjun, ZTE Scientist in optical communication and OSA Fellow, “ ZTE has extended researches on 400G transport technologies for a long term and solved a variety of key technical problems. The probability shaping technology used in this experiment lengthens the transmission distance by 40%.”

ZTE cited a number of other optical transmission milestones:

  • In 2015, ZTE together with OFS released a new 400G ULH high-speed transmission record by transmitting 128.8-GBaud QPSK WDM signals over 10,130 km and 6,078 km on terrestrial fiber links.
  • In 2016, ZTE transmitted 120GBaud 16QAM signals over 1,200 km on terrestrial fiber links, setting a new 800G transmission record.
  • In 2017, ZTE adopted an enhanced advanced algorithm to transmit WDM signals on standard single-mode fiber links over 2,125 km, breaking the 400G 8QAM signal transmission record.