To infinity... and beyond MCI launches WDM over 10 Gb/s TDM >BY BETH SNYDER, Switching & Transmission Editor

MCI's original 1972 route of 60 circuits between Chicago and St. Louis is about to get a jolt. This week, MCI is expected to announce a field trial of 10 Gb/s OC-192 on that route, with four wavelengths making up two bidirectional wave division multiplexed channels over a single fiber.

This is the first announced OC-192 and WDM real-world combination. The commercial route between Chicago and St. Louis carries voice and data traffic, said Fred Briggs, MCI chief engineering officer.

"The real significance here has to do with developing methods to extend the capability of existing fiber plant," said Traver Kennedy, director of wide area networks for Aberdeen Group, Boston. "Right now, a lot of folks may be asking, 'Why do you need such capacity?' But when you start putting in multimedia applications, the size of the traffic goes up by orders of magnitude-and very quickly.

The Chicago/St. Louis fiber was installed in the mid- to late 1980s.

"If there is any skepticism in the industry, it was, 'Can you really run 40 Gb/s over standard fiber?' With this [field trial], that has pretty much been dispelled," Briggs said. "Once again, we're going to speeds people said you couldn't get to.

The 275-mile network includes one OC-192 regenerator and four optical amplifiers. MCI is teaming with Hitachi for the OC-192 equipment and with Pirelli Cables for the WDM optical equipment in this first trial, already underway for several weeks. During the first quarter of this year, MCI also plans to team with two other OC-192 manufacturers-Northern Telecom and Alcatel Telecom-in similar trials, Briggs said. Results will be examined in the third quarter, and MCI will then choose suppliers for the commercial deployment expected in the fourth quarter, Briggs said.

All three partners have said the test route has been running at a lower-than-expected bit error rate.

"10 Gb/s is very sensitive. A lot of the support of this technology is fine-tuning," said T.C. Nie, Pirelli's vice president of product marketing and engineering.

Hitachi officials see the MCI trial as just the beginning for OC-192 time division multiplexing and WDM combinations.

"Every major carrier has talked to us about OC-192 and WDM," said Phil McCall, Hitachi vice president of account marketing.

"There is no limit to the demand for TDM business, and WDM will always be used where it makes sense," said MCI's Briggs.

"I've been recommending WDM and OC-48, but on specific backbone routes, OC-192 makes sense," said Yankee Group analyst Randy Carlson.