NTT has successfully tested technology for optical Internet backbone connections that can transmit 400Gbps on a single wavelength.

Working with Fujitsu and NEC, the Japanese telecommunications giant verified the digital coherent optical transmission technology for distances of several thousand kilometers to 10,000 km. With it, a single wavelength of light can carry 400 Gbps, four times the capacity of previous systems. Each fiber can carry multiple wavelengths, and many fibers can be bundled into one cable.

The approach could more than double existing capacity to meet ever-increasing bandwidth demand, especially by heavy data users.

The technology could be used in the next generation of backbone links, which aggregate calls and data streams and send them over the high-capacity links that go across oceans and continents. The fiber in the network would stay the same, and only the equipment at either end would need to change.

While the current capacity on such links is up to 8Tbps (terabits per second) per fiber, the new technology would make a capacity of 24Tbps per fiber possible, according to NTT.

"As an example of the data size, 24 Tbps corresponds to sending information contained in 600 DVDs (4.7 GB per DVD) within a second," an NTT spokesman wrote in an email. "The verification was done using algorithms which are ready to be implemented in CMOS circuits to show that these technologies are practically feasible."

To compensate for distortions along the optical fiber, researchers from the consortium developed digital backward propagation signal processing with an optimized algorithm. The result of this and other research is that the amount of equipment required for transmissions over long distances can be reduced, meaning the network could consume less electricity.

"We are extremely excited to show this groundbreaking performance surpassing 100 Gbps coherent optical transmission systems," Masahito Tomizawa, executive manager of consortium leader NTT Network Innovation Labs, wrote in an email. "This new technology maintains the stability and reliability of our current 100 Gbps solutions while at the same time dramatically improving performance."

The consortium said it is taking steps toward commercialization of the technology on a global scale but would not say when that might happen.