Amplifiers boost regeneration distance

Amplifiers boost regeneration distance

BEN HARRISON

An expanded optical amplifier facility at Pirelli Cables North America in Lexington, SC, is expected to produce several types of optical systems for voice, data and video transmission. Among these systems is an optical amplifier designed to increase the distance telecommunications lines can cover before transmission-signal regeneration is required. This distance is estimated at more than 200 kilometers, compared to 60 km now.

Previously, Pirelli`s optical amplifier manufacturing facilities were centralized in Tregastel, France. The facility in France will continue to make optical amplifiers, but the new facility in Lexington helps meet increasing product demand.

While optical amplifiers were the focus of a company milestone ceremony for Pirelli at its Lexington facility in September, Giuseppe Morchio, chairman and chief executive of Pirelli Cables from Milan, Italy, also outlined Pirelli`s business plans in his remarks. "This optical systems facility is representative of Pirelli`s worldwide commitment to develop commercial photonics-based products."

Describing the growth of optical amplifiers since late 1993, when Pirelli first supplied them to MCI Corp., Morchio noted that more than 2000 Pirelli optical telecommunications systems have been installed in North America (see Lightwave, October 1995, page 3). He added, "These Pirelli systems support telecommunications routes from Atlanta to Chicago; from Chicago to Salt Lake City; and from California to Missouri. To support these telecommunications systems products, Pirelli continues to make substantial investments not only in buildings and equipment, but also in people."

Morchio reported that there are more than 800 employees working in five worldwide coordinated research and development centers. About 65 research employees are based in Lexington. He said Pirelli`s business strategy is increasingly focused on supplying telecommunications carriers, cable-TV providers and multimedia operators with optical-systems intensive networks.

Eugenio Razelli, president of Pirelli Cables North America, remarked that the expanded optical systems facility opened on the date that the company`s fiber cable-plant celebrated its 10th anniversary in Lexington. He noted that employment has grown to 300 people, and Pirelli`s investment in South Carolina totals more than $100 million.

Pirelli officials are planning to invest almost $90 million in their U.S. facilities during the next four years. Currently, the plant in Lexington has capacity to make about 1.5 million fiber-kilometers of cable per year. This capacity is expected to double during the next three years.

According to South Carolina Governor David Beasley, who spoke at the ceremonies, "Pirelli`s Lexington plant is expected to develop technology that communications carriers such as BellSouth, MCI and Sprint are counting on to boost service and clear traffic jams on the information superhighway."

Increased transmission volume

Pirelli`s photonic multi-wavelength systems are claimed to increase the number of simultaneous telephone conversations over a single optical fiber by 300%, a fourfold increase from 30,000 to 120,000 conversations. The company is also working on an advanced optical amplifier to increase carrier capacity by 700%.

According to Virginia Brooks, manager of network access technology for the Aberdeen Group, in Boston, "Any communications device that can improve distance has significant impact, providing it maintains or improves speed and ultimately results in cost savings. Increased network capacity is an especially attractive feature."

Stephen Montgomery, vice president and chief operations officer at Electronicast Corp., San Mateo, CA, says, "Optical amplifier systems packaging is Pirelli`s first probe into the systems business area." He notes that Pirelli`s implementation of its major worldwide corporate market strategy, based on systems packaging, follows the same shift in market strategy as AT&T Network Systems, Morristown , NJ.

"Both Pirelli and AT&T`s market strategies demonstrate an industry trend toward moving upward to system packaging," Montgomery says. "AT&T already manufactures and internally supplies all of the optical amplifier components. The new market strategy requires AT&T to reshuffle its internal component suppliers. Pirelli, however, needs to acquire several of the components from outside suppliers."

Montgomery also notes the market forecast for optical amplifiers. His firm says North American consumption of fiber-type amplifiers in 1994 totaled $118.6 million. The annual consumption of fiber amplifiers will rise at an average rate of 17.8% per year, to reach $268.9 million by 1999. The study also shows that telecommunications held a 90% share of the fiber amplifier value in 1994, or $106.5 million. Montgomery says this share will decline to 54%, or $309.8 million, by the year 2004.

During a tour of Pirelli`s fiber-cable plant, Craig Lemrow, Pirelli staff marketing manager in market research and analysis, said, "We only keep about three days` inventory in our plant. Corning is our main fiber supplier in North America under a long-term agreement." He further explains that Pirelli supplies fiber in the United Kingdom, Brazil and Italy. The Lexington plant operates three shifts around the clock to produce fiber-optic cable.

However, the centerpiece for the September ceremony was Pirelli`s optical amplifier facility, which is under the company`s Optical Communications Systems, or OCS, business unit. This unit is involved in the research and development, manufacture and deployment of advanced turnkey optical amplifier and wavelength-division multiplexing, or WDM, systems for telephony and cable-TV applications.

According to Neal Stoker, OCS product marketing engineer, "Optical amplifier systems are critical to high-capacity telecommunications systems because of their all-optical operation, high gain, low noise and high-output power."

The primary function of optical amplifiers is to compensate for fiber attenuation, splice loss and connection loss, which limit transmission distance in fiber-optic cable systems. Optical amplifiers eliminate the need for optical-to-electrical conversion, and vice versa, at intermediate sites in long-distance networks.

In addition, optical amplifiers can be combined with WDM systems to increase network capacity on both long-and short-haul routes. WDM combines several optical transmission channels over a single optical fiber, thus allowing the use of common equipment for amplification of the combined signals. A WDM system allows network capacity to be incrementally increased as required over the existing fiber plant, providing cost savings compared to the laying of new fiber cable to expand network capacity.

Stoker says optical amplifier and WDM technologies provide a complementary capability to increase network bandwidth, reduce network capacity congestion and fiber infrastructure investment and provide incremental upgrades in network capacity.

Pirelli`s existing OCS system capabilities are under continuous investigation. For example, several products are under development. They include a drop-insert unit to permit the selective extraction and addition of wavelength channels in a multi-wavelength WDM system, such as 8- and 16-wavelength WDM systems for capacity upgrades to 40 gigabits per second over a single fiber pair.

Advanced research is also underway to develop soliton and 10-Gbit/sec transmission systems and fiber-grating technology for dispersion compensation at high bit rates. q

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