CWDM cost efficient transport in optical networks

Coarse Wavelength Division Multiplexing (CWDM) is the technology of choice for cost efficiently transporting large amounts of data traffic in telecoms or enterprise networks. Optical networking and especially the use of CWDM technology has proven to be the most cost efficient way of addressing this requirement.

CWDM typically has the capability to transport up to 16 channels (wavelengths) in the spectrum grid from 1270 nm to 1610 nm with a 20 nm channel spacing. Each channel can operate at either 2.5, 4 or 10 Gbit/s. CWDM can not be amplified as most of the channels are outside the operating window of the Erbium Doped Fibre Amplifier (EDFA) used in Dense Wavelength Division Multiplexing (DWDM) systems. This results in a shorter overall system reach of approximately 100 kilometers. However, due to the broader channel spacing in CWDM, cheaper un-cooled lasers are used, giving a cost advantage over DWDM systems.

Transmode uses both CWDM and DWDM technologies as a means of transporting different types of services, e.g. Ethernet, SDH/SONET, and Fibre Channel (FC) in metro networks. CWDM is the most cost efficient of the two WDM variants, but has limitations in the distance over which the traffic is transported and in total channel count. With Transmode CWDM solutions, the distance supported is up to 100 km.

Both Transmode’s TM-Series and TS-Series product families are CWDM and DWDM agnostic. This means a CWDM network can initially be deployed with either product series and when required, the network can be simply upgraded to a hybrid CWDM/DWDM network using common cards and pluggable optics. Therefore, by deploying Transmode’s CWDMor DWDM based solutions the lowest possible day 1 cost are enabled without sacrificing the scalability of the network.