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Service providers have always had a hearty appetite for bandwidth. Now it appears to be insatiable.
The high volume of Internet traffic has led to annual bandwidth increases of more than 100 percent in recent years. And even voice traffic is growing at more than 20 percent annually, sparked by rising acceptance of voice-messaging and wireless services.
Moreover, carriers are aggressively moving into video markets such as cable television transmissions, which chew up gobs of bandwidth.
Consequently, telephone companies need to pump more data over their networks, and they would like to boost bandwidth with minimal disruption. They are more interested in products that increase the performance of their existing infrastructures than those that require installing additional communications lines and equipment.
A relatively new networking technique, dubbed dense wavelength division multiplexing, promises to boost bandwidth on fiber-optic lines. The technology, which is still under development, offers performance improvements as high as 1,600 percent.
However, there aren't many commercial dense wavelength division multiplexing products available. In fact, it's been small start-up vendors-such as Ciena Corp., Linthicum, Md.; Lightpath Technologies Inc., Albuquerque, N.M.; Optical Corp. of America, Marlborough, Mass.; and Perelli Inc., Charleston, S.C.-that have paved the way for this technology.
Of the larger companies, Holmdel, N.J.-based Lucent Technologies Inc. was the only established central-office equipment vendor with a dense wavelength division multiplexing product line (the company started shipping such products at the end of 1995) until Alcatel Telecom Inc., Raleigh, N.C., outlined its plans earlier this year.
In the blink of an eye
Wavelength division multiplexing, which emerged from Lucent's Bell Laboratories research organization, uses laser signals to generate light pulses that last for a small amount of time (as little as a billionth of a second). Each wavelength opens up a transmission line on a fiber-optic line that can carry a data, video or voice connection.
The initial iteration of wavelength division multiplexing, which emerged in the mid-1980s, opened up a transmission line which could support as much as 2.5 gigabits per second of bandwidth. This technique is used in many current ATM and Sonet network devices.
However, researchers have been...