MCI builds business case for ULH DWDM network

In another step toward successfully emerging from Chapter 11 bankruptcy, MCI (Ashburn, VA) recently announced plans to deploy a nationwide ultra-long-haul (ULH) DWDM network capable of supporting OC-768 core capacity with transmission speeds up to 40 Gbits/sec. The new network will support 80 wavelengths per fiber pair, scalable to 160 wavelengths. While the network will enable the delivery of bandwidth-intensive applications like Web services, multimedia content distribution, grid computing, and storage networking, "this is not a 'build it and they will come' model," contends Jack Wimmer, vice president of network architecture and advanced technology at MCI. Instead, he says, the business case is based on removing redundant infrastructure, consolidating network traffic, streamlining operations, and lowering operational expenditures (opex).

The 1998 merger between MCI and WorldCom has left the carrier with an amalgamation of duplicate routes, including the dozens of acquisitions made by WorldCom in the 1990s that were never fully divested. MCI estimates it has roughly 25,000 network elements in its network today. The new DWDM ULH network should enable the removal of 50% of these network elements, leaving "fewer elements to manage and maintain—and break," notes Wimmer. Once these elements are decommissioned, MCI will be able to eliminate parallel routes and roughly 45% of the remote shelters currently in service.

Most network routes today extend just 500 km; the next-generation technology MCI plans to deploy delivers four times the reach. The ULH network will feature routes that reach up to 2,000 km without the need for electrical signal regeneration, which typically accounts for 50% of the total cost of electronics in a given network.

The ULH deployment plays into the carrier's longer-term opex reduction strategy as well. When MCI wants to add capacity to its network today, it's looking at a nine- to 12-month process. The carrier has to engineer the route, order the equipment, ship it to the field, install it, turn it up, test it, and commission it for service. Not so with the new ULH technology, says Wimmer. "Once I have the infrastructure in the field, if I need to add a wavelength or 10 wavelengths, I ship a transponder per wavelength to each end, plug them in, and I'm done. I'm plugging in ports rather than building infrastructure. Because my incremental cost is literally just plugging in a couple of transponders, my incremental cost for bandwidth has now dropped significantly. Things like wavelength services suddenly become a lot more affordable in the marketplace."

While Wimmer won't comment on when he expects MCI to begin supporting 40-Gbit/sec wavelengths, he does note that the infrastructure is engineered with 40 Gbits/sec in mind. When demand for OC-768 increases, MCI won't need to build a new infrastructure, he adds. "We'll just plug in the cards just like we do with a 10-Gbit/sec card," he explains. "That in turn lowers the economic threshold that makes 40 Gbits/sec a viable technology."

MCI has selected two vendors, Ciena (Linthicum, MD) and Siemens ICN (Munich, Germany), in an attempt to "maintain a competitive posture," says Wimmer, who adds that each vendor will have to earn every bit of the business it receives.

Ciena will provide its CoreStream optical transport and switching platform, which features reconfigurable wavelength switching that will allow MCI to adapt its network to changing traffic demands remotely via software. The platform also includes high-performance amplifiers with dynamic gain-flattening, enabling un-regenerated signal propagation of 3,200 km and more. Tunable lasers, a standard feature in the company's 10-Gbit/sec transceivers, provide remote dynamic provisioning while lowering maintenance and sparing requirements.

Siemens, meanwhile, will supply the SURPASS hiT 7550, a transpondered DWDM transport platform optimized for high-capacity transport over regional, LH, and ULH networks. Remotely configurable optical add/drop multiplexers (OADMs) redirect traffic on the fly, while three different amplifier types—basic, standard, and extended—address the various distance and capacity requirements of each route. Like CoreSteam, the SURPASS hiT 7550 includes tunable-laser technology to simplify sparing and installation.

MCI also plans to deploy technology it developed in-house, including a new "generic" network management system, designed to alleviate its dependence on a multiplicity of vendor-developed systems, and a next-generation optical fiber it calls "medium-dispersion fiber" (MDF), which, the company claims, increases the usable spectrum by 50%, enabling more bandwidth to be carried over a greater distance with lower impairments. MCI worked with several fiber manufacturers, eventually selecting OFS (Norcross, GA) to supply its medium-dispersion TrueWave REACH fiber.

According to Wimmer, MCI has no reservations about deploying such cutting-edge next-generation technology. "The key is to make a solid business case around the technology," he asserts. "[T]his is a strategic investment that makes sense from the perspective of streamlining our business and lowering our unit costs."

MCI will mitigate some of the risk in deploying new technology by thorough front-to-back testing, says Brian Washburn, senior analyst, consumer network services at Current Analysis (Sterling, VA). "By the time the equipment hits the field, it's already been tweaked 40 million different ways in the lab. If they announce a deployment, they'll be fairly confident it's going to deliver up to snuff," he says.

Beyond the internal operational savings the new network will afford MCI, it may be good for the industry as well, prompting other carriers to take similar action. "I'm sure the other folks aren't going to sit still and let MCI do this without looking at or revisiting some of their DWDM plans as the technology evolves," says Washburn. Analysts at KMI Research (Providence) cite AT&T and Sprint as possible candidates for network upgrades; both carriers operate fiber-optic networks with routes that date back to the early 1980s.

Meghan Fuller is the news editor at Lightwave.

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