Posted: 18th Jan, 2012 By: MarkJ


The Japan-based
NEC Corporation (NEC), a global electronics and communications giant, appears to have
set a new record after it demonstrated the ability to send
1.15Tbps (Terabits per second) of data by using a single laser and over a single "
ultra-long haul" (10,000km) fibre optic cable (no repeaters) via
optical superchannel technology.
The firm later expanded upon the demo by bonding four "
superchannels" together via
Wavelength Division Multiplexing (WDM) technology, which splits the different colours (spectrum) of light in order to transmit more information at the same time, and was then able to achieve a total capacity (connection speed) of
4Tbps.
Dr. Yasuhiro Aoki, General Manager for NEC's Submarine Network business, explained:
"This success is another example of NEC's continuing leadership in high capacity, long distance optical communication technologies, following its record achievements of 101.7 Tb/s per fiber for single core fiber transmission, the first terabit field trial with coexisting 100G, 450G and 1T signals on the same fiber, and the highest order QAM optical transmission of 1024QAM."
The results are important because they open up a new "
cost-effective" and more practical solution for the high-capacity transmission of internet / data links over long
transoceanic (undersea) fibre optic communication cables. Such developments could also
help to bring down the cost of bandwidth for us all and ultimately give ISPs greater flexibility to adapt as demand continues to rise.
Now for the optical scientists among you.. NEC's system uses optical multi-tone generation, large-core/ultra low-loss fibre, intradyne digital coherent detection, and digital equalization at higher oversampling, along with well-established technologies such as EDFAs and DP-QPSK modulation. The experiment yielded a
2-dB system margin above the hard decision FEC threshold without using processing-intensive MAP or MLSE algorithms. Which is nice, we think.