Faster and Faster Fiber

University of Bristol

University of Bristol (Photo credit: Wikipedia)

One thing that is certain is that mankind’s base of knowledge is growing rapidly. This article that human knowledge is doubling every thirteen months and that with the Internet of Things that could accelerate to a doubling every twelve hours!

We certainly see evidence of the growth of knowledge because it’s rare any more to go more than a few days without reading about some new breakthrough that is going to improve telecommunications and computing. Following are two new breakthroughs having to do with fiber speeds that I have seen in the last week:

Noise Free Fiber.  A research team led by Xiang Liu of Bell Labs announced that they have been able to use a technique called phase conjunction to greatly decrease the noise and thus increase the efficiency of a long-haul fiber transmission. They were able to send a 400 Gigabit per second signal for 12,800 kilometers (nearly 8,000 miles).

This technique is the photonics equivalent to the same technology that is used in noise-cancelling headsets. The scientists were able to send twin beams of light down the same fiber and superimpose the two beams in such a way as to cancel out all of the distortion and noise that generally interferes with a light transmission. Essentially the second beam of light acts as the inverse of the first beam by sending them out of phase with each other and eliminating the introduction of external noise into the harmonics of the light beam.

This technique promises to greatly improve the efficiency of long-haul fiber transmissions allowing for much more usable data to make it through the same data path. Sending 400 Gigabits for such a long distance is huge improvement over what is available with current fiber technologies.

Petabit Fiber Networks.  Another set of scientists have taken a different approach to pushing more data through a fiber network. Researchers at the University of Bristol in the UK along with the National Institute for Information and Communications Technology in Japan have reported the creation of a software technique capable of handling huge amounts of data across fiber.

They have been able to control a fiber network consisting of signals across multiple fibers. This is a huge step because it is the beginning of software-defined networking (SDN) on a big scale. With SDN technologies the amount of bandwidth on the network can be controlled and defined by the software rather than depending only on the lasers. This means that the characteristics of the network can be changed on the fly as is needed by demand. Current fiber networks are limited by the amount of bandwidth that can be handled by the laser used on one fiber pair. But with this new SDN technology many pairs of fiber can be tied together into one big network, much like VDSL bonds together multiple copper pairs to make a bigger data pipe to a home.

The SDN technology is needed because there have been trials of combining multiple fibers. Scientists at NTT, the Japanese telecom company have successfully bonded twelve fiber pairs to create a single network that was able to send a huge data pipe of 818 terabits for 450 kilometers (280 miles). That is getting very close to petabit speeds (1,000 terabits).

The SDN breakthrough holds out the promise of making fiber networks programmable. This would be similar to what has been done with radios over the last decade in that the frequency of a given transmitter is now programmable instead of being defined strictly by the power source and the antenna structure. Programmable radios can be quickly changed to fit specific bandwidth needs and if the same can be done with fiber networks, network owners will be able to quickly reconfigure networks to meet changing demand.

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