Wishing upon a WaveStar: Lucent doubles capacity of DWDM system

Lucent Technologies is putting the squeeze on wavelengths traveling over a single fiber, increasing the number of channels from 80 to 320 and the speed from 400 to 800 Gb/s, thanks to a technology that allows wavelengths to travel closer together. With the increase, Lucent hopes to allow carriers to take greater advantage of fiber in the ground by freeing up more spectrum.

The WaveStar OLS 800G will be the next generation of the WaveStar OLS 400G. With the upgrade, carriers can use dense wave division multiplexing (DWDM) to allow for 320 wavelengths, each transmitting information at 2.5 Gb/s. Plus, the 800G can use interleaving - a wave-packing technology - to combine the 320 wavelengths to provide 80 channels at 10 Gb/s.

Lucent's development of the 800G stems from the company's intention of providing solutions to three key problems facing carriers today, said Kathy Szelag, vice president of marketing for Lucent's optical networking group.

First, for carriers with older fiber that cannot handle 10 Gb/s DWDM systems, the 800G will let them take advantage of capacity at the 2.5 Gb/s level instead of the 10 Gb/s level. In addition, carriers that lease wavelengths will have more wavelengths to offer. And carriers whose main applications consist of connecting directly into an IP router can take advantage of OC-48 rates, Szelag said. "They'll have a bigger network to plug into." OC-192 rates will come along soon, she added.

Although Lucent does not expect to make the 800G commercially available until early 2001, Global Crossing has agreed to test the system later this year. But the delay in product availability could be a hitch in Lucent's plans, said Tam Dell'Oro, founder of the Dell'Oro Group.

"It's like dog years," she said, referring to the time lapse between last week's announcement and actual product availability. "Carriers need to satisfy demands now. This market is moving so fast that, if someone else gets product in now, one year from now, the market might be different."

In addition to agreeing to test the WaveStar 800G, Global Crossing also has signed up to test the LambdaRouter, Lucent's optical switch that uses microscopic mirrors to route optical signals. Global Crossing's goal in testing the equipment is to ultimately be able to offer intelligent wavelength services, said Mike Coghill, senior vice president and chief network engineer for Global Crossing.

The carrier plans to deploy three LambdaRouters - two in the U.S. and one in London - to lay the foundation for optical private-line services and move optical interfaces closer to the customer to allow for greater scale and control, Coghill said.

Eventually, the LambdaRouters should allow Global Crossing's edge traffic to directly interact with the optical layer, regardless of the protocol. "The idea would be, through a number of possibilities, to use digital wrappers on some interfaces that make [the transmissions] rate- and format-agnostic," Coghill said. "The two key building blocks are a high-capacity DWDM system and an optical switch." Whether these building blocks will come from Lucent will depend on the results of the tests, he added.

Lucent plans to increase the LambdaRouter's capacity - from routing 256 signals to 1024 signals - which should allow Global Crossing and other carriers to route 40 times more traffic per second than what currently travels across the Internet. This 1000-port capacity is a must for service providers hoping to implement wavelength routing in their networks, said Chris Nicoll, director of optical infrastructure for Current Analysis.

Lucent and Nortel Networks continue to vie for the No. 1 spot in the optical switch market, with systems that scale to the same size. While Lucent developed its switch in-house, Nortel has its recent Xros acquisition to thank for its optical switch. "Lucent fired first with the LambdaRouter. Nortel responded with Xros," Nicoll said. "The challenge will be with the software wrapped around [the switch] to allow for the intelligent switching of lambdas."