November 5, 2003 11:31 AM PST
Standard boosts fiber-optic bandwidth
The International Telecommunications Union on Wednesday said the G.695 standard applies to technology called Coarse Wavelength Division Multiplexing (CWDM). ITU supports CWDM because it lets metropolitan fiber networks expand capacity at a cheaper price than the incumbent technology, called Dense Wavelength Division Multiplexing (DWDM).
CWDM is cheaper because it allows greater spacing between channels on a fiber-optic line and, therefore, can handle less-expensive "uncooled lasers." Geneva-based ITU said operators using CWDM can reduce costs by 30 percent compared with DWDM products.
"The goal is to utilize WDM technology, but provide lower-cost systems," said Jerry Shrimpton, an ITU spokesman in the United States. "The benefit of (CWDM) is a much lower cost system than Dense WDM."
CWDM and DWDM technologies are found in products on the sending and receiving end of fiber-optic networks. These network products allow providers to deliver information-- such as voice, video and data--at high speeds over fiber-optic lines.
CWDM also lets providers activate dormant fibers--commonly known as "dark fibers"--for their own uses. The telecommunications boom in the 1990s left many metropolitan areas with a glut of fiber, much of which is not currently in use.
The G.695 standard applies to CWDM systems for optical networks from 40km to 80km long. The technology supports wavelengths between 1270 nanometers and 1610 nanometers--a nanometer is a billionth of a meter--and signal rates of 2.5 gigabits per second and 1.25gbps.