Optical networking zooms ahead
Source: InfoWorld
Publication date: 2001-07-16
Arrival time: 2001-08-23
Sales of 40Gbps equipment with increased fiber-optic capacity offer carriers enhanced services
OPTICAL-EQUIPMENT manufacturers are on the brink of releasing equipment that supports 40Gbps network transmission speeds - four times current data rates, and the equivalent of transmitting seven CD- ROMs worth of data in one second.
The promise for carriers of 40Gbps optical networking is a lower cost per bit for sending data than with current 10G optical technology. The potential exists for benefits of the technology to spill over into the corporate market and allow users to implement services such as optical networked storage and optical VPNs.
Vendors of 40Gbps optical networking are expected to begin selling 40Gbps optical equipment to carriers by the end of the year. Vendors such as Lucent, Nortel, Alcatel, Ciena, and Optisphere Networks, a subsidiary of Siemens, are developing the new technology, says Chris Nicoll, vice president of telecommunication infrastructure at Current Analysis in Sterling, Va.
Links between Washington and New York or London and Paris, where capacity demands are great, could be the first to use the technology. But the demand for high-octane optics hasn't reached large sections of the United States or other parts of the world.
"Has anyone in the Dakotas asked for OC-192 [10Gbps optical technology]?" commented a representative of one U.S. carrier, who asked not to be named. "No. The demand is not there."
Fiber-optic technology sends data in the form of light impulses across glass or plastic wire or fiber. The base data transmission rate for fiber optics is called OC-1 or Optical Carrier-I and it sends information at a rate of 51.84Mbps.
Products for OC-192 networks are well-developed, and most carriers have completed or are in the midst of implementing OC-192 networks, according to industry analysts. The 40Gbps standard is referred to as OC-768.
Each leap in fiber-optic transmission speed has come with new challenges, and the jump to 40Gbps optical via a single wavelength presents technical, financial, and even marketing obstacles.
On the technical side, 40Gbps optical networking requires closer proximity of the pulses of light that send the signal across the fiber, so there is a greater chance that signal degradation will occur, says Will Russ, Optisphere's senior manager of solutions marketing. As the signal moves along the fiber, it must be cleaned up and amplified to keep it in its truest form.
The fiber used to send the 40Gbps signal also must be more refined to reduce distortions over long distances, Russ says. Some fiber- optic cable that was laid during the 1980s and early 1990s in the United States may not be ideally suited for use with 40Gbps technology because of its inability to keep a signal pure. A problem known as PMD (polarization mode dispersion) can occur, which causes pulse dispersion and, ultimately, affects transmission quality.
Financial challenges of 40Gbps optical networking are similar to the ones that arose with the development of lOG technology, says Scott Andrews, CEO of Picosecond Pulse Labs in Boulder, Colo., which makes optical components for companies such as Coming.
Typically, carriers that buy 40Gbps optical equipment want a cost- benefit model that gives them four times the network capacity for 2.5 times the cost of existing OC-192 networks, Andrews says, adding that currently the financial model appears to be more costly than that.
Initial implementations of 40Gbps equipment are expected to let carriers use existing lOG technology, Current Analysis' Nicoll says. Four OC-192 signals will be streamed over a single 40Gbps wavelength to provide greater service economics.
Still, adoption of 40Gbps optical networking could be slowed by the current industry spending slowdown and by carriers buying lOG gear that can offer 1.6Tbps capacity using DWDM (Dense Wavelength Division Multiplexing), says Sterling Perrin, a research analyst at IDC.
Although manufacturers including Lucent and Nortel plan to roll out 40Gbps optical networking equipment by the end of 2001, it may be 2003 before true adoption begins, he cautions.
"Ultimately it boils down to the fact that people are only going to adopt 40Gbps if it makes economic sense," Perrin says.
The need for speed
JAMES EVANS
James Evans is a former member of the IDG
News Service, an InfoWorld affiliate.
Copyright InfoWorld Publications, Inc. Jul 16, 2001 |
