ZTE Corp. (0763.HK / 000063.SZ) says it has successfully transmitted a single-carrier 800-Gbps signal over a long-haul link. The company says it used electrical time-division multiplexing (ETDM)-based 16QAM to send a 120-Gbaud WDM signal 1,200 km of TeraWave fiber from OFS.
The signal benefitted from the application of optical pre-emphasis on the transmitter side and maximum likelihood sequence estimation (MLSE) on the receiver side.
ZTE says it transmitted 12 WDM channels on a 150-GHz grid. Each channel transmitted a total of 960 Gbps, 800 Gbps of data signals plus 20% forward error correction (FEC) emulated overhead bits. The 1,200-km link comprised 100-km spans of the "base" version of TeraWave fiber that features a loss of 0.184 dB/km and an effective area of 125 μm2, according to a source at OFS. The transmission achieved spectral efficiency of 5.33 bps/Hz.
"Thanks to the high-baud-rate signals generation, transport interfaces with bit-rates of up to 1 Tbps will be achieved in the near future,” predicts Dr. Jianjun Yu, chief scientist at ZTE US Optical Lab and Fellow at The Optical Society (OSA). “We can expect that bit rates beyond 1Tbps, such as 1.6 Tbps, will be introduced as Ethernet standard rates since it would be a logical upward path rate from the 400 Gigabit Ethernet interface, which is based on high-baud-rate signals and high-order modulation formats. ZTE has been relentless in pushing forward-looking research and development on the single-carrier 400G transmissions and beyond, and we have key technologies for future terabit-per-second solutions."