In the DWDM system, there are single-fiber bidirectional and dual-fiber bidirectional, single-fiber bidirectional: realize the simultaneous transmission of optical signals in two directions in one optical fiber, and modules of different wavelengths form one signal, dual-fiber bidirectional: only one optical fiber is completed The transmission of signals in one direction and the transmission of optical signals in the reverse direction are completed by another optical fiber, and the wavelength of the optical signals on the two optical fibers is the same. Por FS.COM en 24 de jul. de 2022