The characteristic of the open DWDM system is that there are no special requirements for the optical interface of the multiplexing terminal, and only these interfaces are required to comply with the optical interface standard

recommended by ITU-T. The DWDM system adopts wavelength conversion technology to convert the optical signal of the multiplexed terminal into a specific wavelength, and the optical signal of different terminal equipment is converted into

different wavelengths that comply with ITU-T recommendations, and then multiplexed.