Long-distance relationship

Williams Communications secured its place in the telecom history books when it revealed the successful results of a 6400 km all-optical transmission using Corvis' technology.

Last July, Williams and Corvis completed a 3200 km all-optical transmission. Shortly thereafter, Broadwing sneaked past Williams with a 4000 km transmission, also using equipment from Corvis. But Williams' latest achievement is significant because the carrier proved its ability to offer coast-to-coast wavelength services.

Williams has not yet kissed its regenerators and repeaters goodbye; the 6400 km transmission was a “stress test” for its fiber and infrastructure to determine the system's capabilities, said Chris Hamilton, chief technologist of optical transport architecture for Williams.

Once William's turns up its 33,000 mile multiservice broadband network, which is currently under construction, ultra-long-haul platforms such as Corvis' will bring more functionality to the table, decrease the cost per bit and add capacity, he said. And following its multi-vendor strategy, Williams plans to roll out another ultra-long-haul platform on its network over the next few months, added Hamilton.

Broadwing, however, wasn't impressed with the 6400 km figure.

“Distance is only part of it,” said Chris Rothlis, vice president of engineering for Broadwing. “The other part is having the network infrastructure that is flexible enough to meet growing demands.”

Along with the ability to do away with repeaters in the network comes the benefit of not needing to roll trucks in order to add capacity, said Rothlis. “We need to get at least 4000 km out of it to be cost-effective in the marketplace,” he added.

In addition, the ability to carry dense traffic, such as video or broadcast TV, without having to slow down for regenerators or repeaters also will reduce latency, dropped packets and jitter, said Andy McCormick, senior analyst of optical communications for The Aberdeen Group. If a carrier wants to send broadcast TV today from New York to Los Angeles, the many hops in between would cause delays.

“Now, with a single span, you won't have to slow down,” he said.

Indeed, Corvis says ridding networks of regenerators, amplifiers and other associated costs will save carriers 50% to 70% on the capital costs—and 75% to 80% of the operational costs—of long-haul platforms. While the distance of the transmission is key, offering revenue-generating services is also important, said Shyam Jha, vice president of marketing for Corvis.

“2001 is the year for revenue generating services,” he said. “Carriers need new ways to get money.”

Plus, additional functionality will be important when it comes to offering wavelength services, as well as reducing cost at the same time, said Jha.

While transmitting 6400 km without regeneration is a “huge step” in terms of distance, not all carriers need the capability, said McCormick.

“Qwest or Global Crossing will sit up and take notice,” he said. “But how many spans out there are 6400 km?”

Demand for ultra-long-haul platforms and for the ability to transmit signals across such long distances will vary on a case-by-case basis, depending on a carrier's network architecture, added McCormick.

Williams' demand for ultra-long-haul led to an expanded agreement with Corvis to total $300 million over multiple years. Broadwing signed an agreement in August with Corvis to purchase $200 million of equipment, which the carrier is installing in its network. Broadwing's all-optical link between Fort Worth and Phoenix is operational, and the company expects to unveil other portions of its three-ring network in the coming weeks, according to Rothlis.

Now that Williams and Broadwing prove they can go the distance with ultra-long-haul, all eyes have turned toward the metro, said Rothlis.

“We have to navigate the metro and [take] the ultra-long-haul pipes out to the customers.”