Lighting the way

The people behind MCI's network evolution are hopeful technology innovation inside and outside its walls will help push its vision of an all-optical network.

Like most network operators that are adapting and upgrading their networks, MCI's shift is driven primarily by the increase in data traffic demands. As it adapts, however, the carrier must not ignore the voice customers that have helped MCI build its business.

"That is happening in a time when there's a huge amount of technology coming into the marketplace," says Jack Wimmer, executive director of network technology and planning at MCI. "We look for a way to leverage all that technology to build a network optimized for data in a way that doesn't penalize our existing revenue stream."

Still, moving and managing data traffic has become an increasingly important priority. Knowing that, MCI has opted to combine its efforts and create an integrated network rather than build separate transport operations for separate types of traffic.

"The data piece is still relatively small compared to traditional services, so the economic way to build data networks today is as an overlay," Wimmer says. "But if you draw out the curves, a couple years down the road that changes very quickly."

The road to that integrated vision, Wimmer says, is paved with fiber. As MCI moves toward a fully integrated network, fiber will provide the common path. Wavelength division multiplexing (WDM) technology, meanwhile, will help the carrier segregate data traffic and build a data-optimized network on that portion of the fiber, essentially creating virtual fiber.

"WDM is essentially a tool that effectively multiplexes our fiber plant," Wimmer says. "The technology is coming together so that we will be able to build the transport piece entirely in the optical domain."

WDM is also the mechanism that will help make that effort more economical, Wimmer says. Carriers have traditionally spent money on multiplexing gear at the end points of their networks to pack more traffic on the transport piece, which has historically been the most expensive portion of the network to upgrade. With WDM, upgrading the transport piece becomes more affordable, so carriers can save more money at the end points, he says. "With the advent of WDM and optical amplifiers and high-speed systems, that distance-sensitive portion of the overall cost becomes less," Wimmer says.

Reliability is one of MCI's most prominent concerns in migrating to a converged voice and data network. All types of traffic carried over MCI's network will be subject to reliability expectations, he says, but the carrier will adapt its architecture and restoration techniques to account for variances between voice and data.

"In the voice world, you worry about things like transmission loss and echo control. In the data world, the model brings things like latency and packet loss and cell loss," Wimmer says. "We will build the network for the most stringent demands, but there are things you can do in provisioning the network that affect how you perform restorations."

MCI is confident that its focus on migrating toward an all-optical backbone-coupled with developing technologies that will continue to multiply the capabilities of its fiber plant-will help the carrier answer the changing needs of its customer base. "There is more new technology coming on-line that will make additional fiber bandwidth available," Wimmer says. "The fiber that's in the ground will supply many, many times what the demand is."