DWDM is a technology that sends multiple data through a single network link. At the transmitting end, there is an optical multiplexer, which can converge two or more optical signals of different wavelengths. At the receiving end, optical demultiplexer is used to separate the signal, and the signal loss caused in the process can be reduced by optical amplifier. Therefore, DWDM connection can be used for long-distance data transmission, because it can increase the bandwidth on the existing fiber network.
OTN represents optical transmission network. It provides a whole network framework, which adds SONET / SDH like functions to WDM devices, such as performance monitoring, fault detection, communication channel and multiplexing hierarchy. It works in the first layer and collects various tasks into the tunnel of WDM technology, thus increasing the transmission distance and optical fiber capacity. This means that OTN frame structure combines the flexibility of SDH / SONET technology with the bandwidth expansion ability of DWDM, so that it can provide the transmission, multiplexing, routing, management, supervision and survivability of the optical channel carrying the customer signal.
DWDM is a point-to-point system, while OTN is composed of OXC and OADM, which has functions such as optical cross capability and wavelength conversion. OTN is developed on the basis of DWDM technology to optimize the existing resources of transportation network. In addition to providing high-capacity DWDM transmission, OTN also allows different DWDM channels to be switched according to service requirements.
OTN network outperforms DWDM Network in terms of wavelength, standard multiplexing hierarchy and end-to-end optical transmission transparency, security and networking functions.
