Dense Wavelength Division Multiplexing (DWDM) network is the most effective and feasible solution to achieve long-distance fiber expansion, which has been widely recognized by the people. In practice application, apart from increasing network bandwidth, we also need to focus on the fact that how to use DMDW system to extend the transmission distance of the network.
Although the longest transmission distance of 10G DWDM SFP+ optical module is up to 80km, due to the optical signal will cause loss during the transmission process, to ensure the receiving quality of the optical signal, we usually need to deploy pre amplifier (PA) in front of the optical receiver to improve its reception sensitivity. In addition, also dispersion compensation module (DCM) can be used to process the accumulated dispersion in the link in the case do not regenerate the wavelengths in the link anymore. The following diagram is a concrete example of this network:
As we know, the longer transmission distance, the more loss will be caused. If we want to use 10G DWDM SFP+ optical module in the DWDM network with a transmission distance of 120km, multiple optical amplifiers must be increased, as shown below, apart from deploying PA and DCM, BA is also necessary to be added on the multiplexer end to ensure the transmission distance of the optical signal up to 120km.
The three instances above are simple construction diagrams of DWDM networks, we need to pay special attention to the optical loss and the budget of the dispersion compensation in the practical application. Whichever kind of DWDM network you want to build, the optical communication products below have to be used: