Lucent brings management to WDM

Taking an idea from under the sea, Lucent Technologies has developed a means of adding intelligence to wave division multiplexing systems. The WaveWrapper, which will be integrated into the WaveStar OS400G dense WDM system technology, provides management information for individual wavelengths. WaveWrapper eventually will enable packet-based traffic to be transmitted directly on the optical layer.

The WaveWrapper adds "a small burst of digital information to each individual wavelength," said Kathy Szelag, vice president of marketing in Lucent's optical networking group. It contains information about the source, destination, power level, performance and forward error correction for the specific wavelength. The destination WDM system picks up the overhead information, but "doesn't mess around with the light," she said.

Lucent has proposed the technology to three standards bodies in an effort to create a non-proprietary WDM management system. The company also published detailsfor building similar systems. "It's not private or proprietary," Szelag said.

Nor it is altogether new. WaveWrapper is based on a standard currently used in undersea cabling systems.

Alternative solutions exist. One is the pilot tone approach, which is similar to Sonet in that it adds an extra wavelength for overall performance monitoring. Another solution, dubbed "Sonet Lite," uses a simplified version of Sonet's data communication channel.

The key problems in optical networking are monitoring and maintenance issues, said Mathew Steinberg, director of optical networking at RHK. With today's Sonet framing in place, "all we can monitor is bit error and path trace. We'd also like to monitor wavelengths throughout the network, as an example."

Adoption will hinge on standards, he said. Other network elements, such as regenerators, must be able to read the WaveWrapper information. That means carriers must build WaveWrapper networks alongside existing networks, something they will be reluctant to do if the technology is not standardized.

"It's not going to be trivial to move from Sonet to WaveWrapper," Steinberg said. "The question [for carriers] is, where are you going next?"