Sending data over optical fiber for long distances normally requires electrical amplification along the way. But that regeneration hurdle and the costly maintenance associated with it may finally have been overcome.
This week, officials at Broadwing Communications in Austin, Texas, said they had successfully tested a 10G bit/sec. all-optical network that looped 4,000 kilometers, from Phoenix to Fort Worth, Texas, and back.
The trial, according to Broadwing, proves the viability of an ultralong-haul fiber-optic transmission system from Corvis Corp.
Optical wavelengths lose signal strength over long distances and ordinarily have to be regenerated -- that is, converted to electrical signals, amplified and converted back to optical wavelengths -- every 500 to 600 kilometers, according to experts. That requires technicians to physically upgrade bandwidth capacity on existing fiber cables at points along the way.
Through a proprietary all-optical amplification technology, the Corvis system can sustain an optical signal over longer distances without electrical conversion, company officials said. That, according to Ann Reidy, an analyst at telecommunications industry researcher RHK Inc. in San Francisco, could ultimately cut the time and costs associated with adding more channels to existing optical fiber.
Dale Richardson, Broadwing's director of engineering, said it took only a day or two to set up the 10G bit/sec. test loop based on the Corvis system. Using standard electrical-signal regeneration technologies, the same provisioning exercise could take up to six months, he said.
Steve Ellis, manager of telecommunications at the University of Notre Dame in Notre Dame, Ind., a Broadwing customer, said optical technologies that minimize the need for signal regeneration should ultimately make adding more bandwidth faster and less costly for communications providers.
But he expressed some doubt about whether the savings would be passed on to large users.
Broadwing officials declined to discuss the costs associated with the technology, which they said should be commercially available by year's end.
But Grier Hansen, an analyst at Pioneer Consulting LLC in Cambridge, Mass., said the potential cost savings are significant.
"Electrical regeneration is very expensive," Hansen said. "Specific numbers are hard to come by, [because] carriers don't want to give them out. But you're probably talking at least a 50 percent savings for provisioning [by going all-optical].