| 释义 |
CWDM (Coarse Wavelength Division Multiplexing) An optical multiplexing technique specified by the ITU-T as 18 wavelengths in the 1270–1610 nm range, with spacing of 20 nm (2500 GHz at 1550 nm). Targeted at networks with a reach of 50 kilometers or less, CWDM offers the advantage of using uncooled laser sources and filters, which are not only less expensive, but also consume less power and possess smaller footprints that the cooled lasers used in Dense WDM (DWDM).While CWDM does not allow channels to be spaced as tightly as DWDM and, therefore, does not offer the same spectral efficiency, it is a cost-effective alternative for short haul metropolitan and local rings supporting applications such as GbE. See also DWDM, filter, GbE, ITU-T, laser, multiplexer, spectral efficiency, wavelength, and WDM. 74570c03.qxd 9/11/07 12:19 PM Page 122 |