Lambdas Bulk Up Lit Fiber

By eweek  |  Posted 2001-07-09

Long-haul and metro network operators are beginning to wring value from already-lit fiber by selling individual wavelengths of light to bandwidth-hungry businesses not rich enough to afford individual fibers for different data services.

Dense Wavelength Division Multiplexing (DWDM) gear allows operators to load on new features and add capacity to their networks more cheaply than lighting new fiber. Those same operators have finally started to take advantage of the boost in capacity by selling specific wavelengths, or lambdas.

Finances are driving the trend. "Carriers are trying to make better use of what they have," said Doug McEuen, senior market analyst at Pioneer Consulting, a telecommunications research firm.

For some lit routes, McEuen and other analysts said, carriers can double capacity by adding lambdas for a fraction of what it might cost to light a comparable amount of dark fiber. Those savings are being passed on to enterprise and carrier customers.

Long-haul carriers such as Broadwing and Global Crossing are using DWDM gear to squeeze more wavelengths onto their lit fiber. Metro carriers Metromedia Fiber Network and Yipes Communications have begun selling multiple lambdas from a single strand of fiber to individual companies and even to other carriers. Sharing reduces the need to dig up streets to install new fiber. And because lambdas are protocol-agnostic, legacy and Internet Protocol (IP) traffic can share the same fiber.

Both MFN and Yipes plan to launch more lambda-based services in the coming months, pitching nearly unlimited bandwidth. The ability to rapidly provision the optical network allows carriers to issue additional wavelengths to a client with a few keystrokes. Carriers also will be able to bundle bandwidth sales with applications such as storage, since non-IP data protocols can share a single lambda. Other applications include voice-over-IP and gigabit Ethernet, as well as uncompressed broadcast video, which can travel across lambdas without being translated into another format.

Lambda-based metro systems also allow carriers to reduce their networks complexity. For instance, MFN uses lambda technology to trim the number of optical switches it uses in the metro core, elevating switching to less distance-sensitive lambda boxes like LuxNs WS 6400. Some operators also use DWDM gear to develop meshed networks instead of costly Synchronous Optical Network, thereby reducing equipment and management costs.

DWDM technology is doubling the number of usable wavelengths every nine months or so, and as the economics of deploying lambdas improve, their carrying capacity is increasing. Though most big carriers are now deploying equipment capable of carrying 10 gigabits per second on a single lambda, Lucent Technologies recently announced lab tests reaching throughputs of up to 160 Gbps.

Later this year, Broadwing, with an 18,500-mile fiber network, will increase the number of available wavelengths per fiber to 64 from 32. Global Crossing and Williams Communications are also increasing the use of WDM and are marketing lambdas in metropolitan areas.

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