Ciena Corp. has added Dynamic Wavelength Routing capabilities to its flagship CN 4200 Advanced Services Platform, creating a hybrid electrical and optical ROADM design to combine whole and subwavelength switching.
The eight-degree ROADM is an in-service upgrade to the existing CN 4200 platform through use of a universal line card that routes any wavelength or combination of wavelengths to any port, on demand. It eliminates the need for color-specific components and spares.
“What makes it unique is we take a hybrid electrical-optical approach,” said Vinay Rathore, Ciena’s director of marketing, explaining this allows service providers to grow into all-optical technology.
All-optical ROADMs are expensive compared to electrical switching, so many carriers are putting off moving to the technology, he said, noting that industrywide ROADM line cards are about six times the cost of WDM line cards. That’s why last year Ciena rolled out its electronic ROADM, or eROADM, which grooms, packs and routes wavelengths. “Using eROADM, you can improve wave utilization 78 percent versus trying to use a ROADM to solve that problem,” said Rathore.
However, he said, electrical grooming gets expensive when you start to get into the 10 gigabit interfaces. “We wanted to be able to offer a photonic switch so we could migrate or scale up our ROADM capabilities,” he said, explaining that routers and high-speed switches can connect up to the ROADM while lower speed services (up to 10gig) can be groomed via the eROADM before they are put on wavelengths.
“By being able to groom at every location in the network, you make your ring more efficient or your WDM network more efficient, and you get the benefit of the cost implication of electrical first and optical later,” Rathore said. “By combing the two approaches, it starts at a fairly low price point and continues to drop as your 10 gig services grow.”
Ciena’s ROADM card is being used in early customer engagements and is expected to ship in early 2007.
Ciena Corp. www.ciena.com
