Scientists Double Optical Fiber Transmission Capacity

ms writes: "Yesterday golem.de reported that the Optical Communication and High-Frequency Engineering Group at the University of Paderborn (Germany) claims to have made a technology practical which doubles the transmission capacity of optical fibers to 80 GBit/s. In their so-called "polarization division multiplex data transmission system" they don't only send one but two mutually orthogonal light waves through the fiber. They say the only big problem was the dispersal of the light waves which limits the data rate. Additional they had to fight against the phenomena that the polarization direction of the light waves changes while it goes through the fiber. Now, after two years of research, they invented an "automatic optical compensator of polarization mode dispersion" which fights both the limitations. With this gadget they were able to send data at a rate of twice 40 GBit/s (that's 85,899,345,920 Bps) over a test-line of 212 km. And "only the available equipment limited distance and data rate". As we all know, optical fibers build the (cronically overloaded) backbone of our beloved Net. (BTW: That's Net., not .Net!)" Here's the babelfish translation, too.

Remember

[Haxx]

that's 85,899,345,920 Bps

Up from 300 Bps 14 years ago. Not too shabby.

Increasing capacity; increasing vulnerablility

[case_igl]

It seems every year we find a way to double the amount of data that we can send down fiber. As a result of this, companies are actually deploying less new fiber in the field and taking older lines out of commission.

One of the things that worries me about this is the increased vulnerability. In the past, huge fiber networks were used that can be one tenth the size today. All too often a clueless construction worker rips up a section of fiber and causes some havok.

Won't this kind of thing happen more frequently if less fiber is deployed that can handle more traffic? And does this bring us any closer to fiber to the curb - it doesn't seem like it.

Re:Dark fiber

[sllort]

This is going to help the industry alot. Right now there is pleanty of unused fiber, but the problem is the devices that use the fiber take too much room. if we build them smaller and faster we can increase capacity easily.

The other thing that would help the industry would be to stop going bankrupt. Most to all of the CLECs (PS/Inet anyone?) are bankrupt and insolvent, and the major carriers - WorldCom, Verizon, Global Crossing - have horrible credit ratings and a total freeze on capital equipment purchasing. Right now no one is buying next generation optical equipment. Look at Nortel stock... if you bought $1000 of Nortel stock last year, you'd have $43 today. I won't even mention Lucent. Those are the big boys - the small ones (cough Iron Bridge cough) are all dead or dying.

Optical equipment vendors have no customers. Optical equipment manufacturers are slashing R&D and personnel, and relying on existing revenue streams for survival.
Optical network carriers are nearly bankrupt.

...and NO ONE is paying for premium bandwidth.

So pretty much, this isn't gonna help anybody. The next advance in optical networking isn't going to be the next next-generation fiberoptic breakthrough. It's going to be a solvent carrier, or a paying customer for broadband.

It's the switches, stupid.

[NerveGas]

We already have much more fiber capacity than we can use. The real bottleneck of the Internet right now is... the switching. OC-768 units (38.8 gigabits/sec) won't even reach volume production until 2003 or later, and they wouldn't even handle half of one of these fibers, let alone multiple fibers coming from various locations. It's like running a 2" diameter fuel line to the engine of your Hyundai.

All-optical switches have been developed, but are not going to be widely deployed for some time. I have a feeling that even all-optical switches will be many years before they reach the speeds needed for 80 gb/s fibers.

The true improvement of the Internet will occur when switching capacity increases by at least an order of magnitude in a very short amount of time. Right now, good, guaranteed bandwidth is barely any less than it was back in 1997. Sure, as switching capacity slowly progresses to fill the needs of the backbone providers, the Internet keeps running - but you still end up paying out the nose for guaranteed bandwidth. Once the switches catch up with the fibers, however, that *might* change. Maybe.

steve

Beyond 80 Gbps already?

[JimDog]

I don't understand the importance of this discovery. I'm pretty sure existing DWDM systems can put at least 16 wavelengths on a single fiber at OC-192 (10 Gbps) speeds for a total capacity of 160 Gbps...

Re:Dark fiber

[Shotgun]

No, the problem is that the devices that use the fiber are expensive and there is currently a glut of bandwidth. Oh, stop your screaming. It used to be that you'd pay $20/month for 64k of rarely used bandwidth. 64k is the nominal bandwidth assigned to a phone call in modern digital networks. If you made a long distance call (one that traversed central offices), you paid more and by the minute.

An always-on, connect instantly to anywhere in the world, ADSL line has several hundred K of bandwidth, and people scream at anything above $49.95/month. There currently is a glut of supply driving down prices. These next generation inventions will only see production if they can supply more bandwith at the same equipment cost.

In any case, the dark fiber will remain so until someone can light it really cheaply, or someone is willing to pay for the laser.

Re:Dark fiber

[mangu]

The other thing that would help the industry would be to stop going bankrupt.

That's a normal thing in industries. It happened in the 1890's when railroad equipment manufacturers went bankrupt. It happened in the 1930's when car manufacturers went bankrupt.

When an industry is growing, a lot of new companies are spawned. Then, there comes a period of readjustment, when the market gets saturated and there is a mass extinction among companies.

Re:Dark fiber

[Happy Monkey]

In a larger sense, though, the provider bankrupcies are a good business plan for the country. Some companies go bankrupt laying the infrastructure, and then sell it cheap to other companies. These new companies are not saddled with the huge debt from the construction, and can offer the service much cheaper. It's almost like government sponsored infrastructure projects, except the "taxpayers" are voluntary stock and venture capital gamblers.

The equipment manufacturer bankrupcies aren't so good, though.

Re:Beyond 80 Gbps already?

[JimDog]

Indeed, upon further research, we're already way beyond 80 Gbps on a single fiber. DWDM [techtarget.com] (dense wave division multiplexing) can increase the capacity of a single fiber to 1.6 Tbps, and soon to 3.2 Tbps with 80 wavelengths at OC-768 according to this press release from NEC [nec.co.jp]. As the press release states, a 3.2 Tbps data rate is the equivalent of transmitting 1600 feature-length films every second.