FREE SPACE OPTICS FINDS FOCUS

It's a free space free-for-all as carriers take a new look at optics-based technology. Despite its reputation as a fragile and temperamental technology, domestic service providers and foreign carriers are using FSO not only as a broadband backup but also as a viable last-mile technology.

For a technology that depends on straight lines, free space optics is taking a circuitous route to respectability. As its name implies, FSO uses optical laser technology to zap data across open spaces. FSO has intrigued enterprise and carrier network operators for years because it's cheaper to beam data through the air than to build infrastructure with wires.

Free space, though, doesn't mean free of worry. Users can't shoot the beams directly into the sun, buildings sway and knock the laser beams out of alignment and — above all — there's fog. For a FSO laser beam, fog is a brick wall.

“The fog gets you,” said Donnie Burt, vice president of advanced technology for fixed wireless data carrier e-xpedient, which uses FSO to deliver its 100 Mb service in Miami. “I don't feel comfortable putting a laser system up by itself.”

e-xpedient uses 60 GHz radios to duplicate — or parallel — its laser beams. It's also careful where it locates the lasers because, as President, CEO and co-founder Brian Andrew noted: “The sun overpowers whatever the other end is.”

FSO vendors know their limitations and are even willing to concede them. While FSO will never defy the laws of physics, it can provide a valuable last link between the fiber network and the end user — including as a backup to more conventional methods.

A key example was the Sept. 11 tragedy, when carriers learned that having a backup fiber optic network was of little use if both fibers went dark. Qwest Communications, among other U.S. carriers, used FSO “to help put customers back online,” said a company spokeswoman.

Surprisingly, though, Sept. 11 is not the technology's linchpin. Other instances — including a fire in a Baltimore train tunnel that disrupted East Coast data networks — proved the technology's mettle.

“People are realizing that if they have two fibers, they're not necessary protected if it's a correlated event and they both go out,” said Steve Mecherle, chair of the Free Space Optics Alliance and chief technical officer for vendor fSONA. “To have alternate paths using free space optics is getting much more interest from carriers.”

FSO is a technology that is just finding its niche. Michael Sabo, senior vice president of sales and marketing for vendor AirFiber, said FSO is earning a place as more than a fiber backup. “Billions of dollars have been spent on long-haul fiber builds out on the trunks,” he said. “This technology fits the last-mile kinds of applications to fill in all the leaves of those networks.”

Qwest is trying the technology in 27 out-of-region areas to overcome geography issues, a company spokeswoman said. She added that Qwest uses FSO in commercial deployments “because they are the vast majority of the users of Qwest's broadband network.”

“We're pleased with the technology, but we cannot [speculate] about its future deployment in the Qwest market,” she said.

That at least puts Qwest ahead of most other U.S.-based carriers, all of which are looking at some form of FSO but won't talk specifics, according to their vendors.

Overseas, things are a little different. There's a general misconception that the international marketplace lags when it comes to fiber. In fact, many international deployments are so fiber-rich that FSO is merely a bridge between the wires and the customer.

For example, Utfors, a Swedish broadband carrier that operates in fiber-dense Stockholm, Sweden, uses long-distance and metro fiber. Nevertheless, fiber doesn't go everywhere, and it can't always be deployed quickly, said CEO Jan Werne. “In all those cases, FSO is a superb alternative,” Werne said.

Utfors pushes the FSO envelope by beaming signals 1.5 km and using windows-based transceivers rather than rooftop units. Nonetheless, the carrier is getting “as many nines as you would like of reliability,” Werne said.

But Utfors' long-distance success should not delude vendors into believing that they have a technology that can leap tall buildings in a single bound — or perform other physically challenging feats — warned Lindsay Schroth, analyst for The Yankee Group.

“The technology definitely has limitations,” she said. “Fog is a limitation. Distance is probably the biggest limitation. You can't go very far if you're going to have the reliability that a carrier wants.”

Alua, a carriers' carrier in Spain, brushes aside those limitations. “In Madrid, 80% of business users are within 500 meters of fiber,” said Paul Kearney, Alua's chief technical officer. “We plan our [FSO] network by using very short ranges to be within the weather limitations.”

That's wise — and it would be wise for vendors to sell their technology with that in mind, said Bettina Tratz-Ryan, senior analyst for the Gartner Group. “Free space optics really only provides a very limited application when you consider five 9s of reliability. Some of the free space optics companies will tell you that the five 9s are outdated and that they actually have trials with alternative operators that are just going to three 9s and four 9s,” Tratz-Ryan said.

TeraBeam is one of those companies.

“Five 9s is probably the greatest myth that exists today in the world of telecom,” said Dan Hesse, TeraBeam's chairman, president and CEO. “When I'm sitting down with a carrier, they're not going to talk with even a halfway straight face saying they want five 9s in terms of end-to-end service.”

When Hesse sits down with his customers — including carriers and enterprise network operators — he tells them about TeraBeam's 1550 nm delivery system that's powerful enough to go through windows, can deliver signals under the fog blanket and is safe enough that it doesn't blind the casual viewer who happens to look into the beam.

To jump-start FSO, TeraBeam developed its own network in Seattle, where weather is always a consideration. “Our systems work in fog,” Hesse said.

Carrier interest is the future. The present and past for FSO is the enterprise user, such as New York-based advertising agency Tribal DDB Worldwide. Tribal turned to FSO when plans to move all operations into one location fell apart, leaving two distinct but connected operations. The company now links two Manhattan locations several blocks apart — one on the 4th floor and the other on the 21st floor — with FSO.

“What are your options?” asked Ken Corriveau, Tribal's IT director. “You could rent dark fiber, but that would take forever to figure out in the city. You could rent a T-1 or DS-3, but both of those are 30 to 90 days out.”

Tribal's story is relatively common in the enterprise space, said John Griffin, president and CEO of LightPointe, which designs and manufactures optical transmission equipment using FSO technology. It's up to the vendors to convince carriers that it will work on a bigger scale. According to Griffin, carriers are “spooling up” to the advantages of FSO as a way to deliver high bandwidth at a lower cost.

Still, the technology's limitations must be overcome. That's the sort of thing that the Free Space Optics Alliance was formed to pursue, Mecherle said. The first thing is to chart worldwide weather patterns. That “won't be an easy topic to get at, and it won't be out real soon,” said Mecherle, predicting some results in the next six to nine months.

Free space optics, unlike other transmission technologies, isn't tied to standards or standards development. FSO vendors simply attach their equipment into existing fiber-based networks and then use any laser transmission methods they like. This encourages innovation, differentiation and speed of deployment.

And that, in turn, brightens the future for FSO.

“In general, the technology has a lot of future for the carrier networks — if it's marketed well,” said Gartner's Tratz-Ryan.

Which, to many, means that at least FSO cleared the first hurdle on its circuitous obstacle course: It works.