CWDM and DWDM - A Brief Technical and Economic Comparison - Sponsored Whitepaper

Coarse wave division multiplexing (CWDM) systems and dense wave division multiplexing (DWDM) systems provide low-cost, quick and easy to provision bandwidth to meet the needs of many users; telecom, utility, cable, and enterprise. These systems are ideal to meet rapidly increasing bandwidth demands. Both CWDM and DWDM offer significant cost savings when adding capacity to user networks as well as rapid installation advantages for meeting service demands. This paper compares the technical features and some applications of CWDM and DWDM and the relative economics of CWDM and passive (non-amplified) DWDM systems.

Coarse Wave Division Multiplexing (CWDM) CWDM systems are low to medium capacity systems used over distances of 80km to 100km. A total of 18 wavelengths are specified, spaced 20nm apart starting at 1271nm and ranging up to 1611nm as defined by International Telecommunications Union (ITU) recommendations (standards) G.694.2. CWDM systems do not use optical amplification as DWDM systems do so they are normally limited by the loss of the highest-loss wavelength used. ITU standard wavelengths can be multiplexed on to a CWDM system by a transponder which converts a standard 1310nm wavelength to a specific ITU grid CWDM wavelength. Alternatively, the SONET/SDH multiplexer could be equipped with a small form-factor pluggable (SFP/XFP) laser at the required ITU grid CWDM wavelength and would launch directly into the CWDM filters.