3LCDM over WDM system with dispersion compensation is examined with four channels at collective bit rate of 10 Gbps. Optimum cut-off frequency of Gaussian low pass filter at 18 GHz and Gaussian band pass filter at 40 GHz are used. By varying the input signal power, optimum received power of the system is determined that is required to achieve BER of 10-9. For optical communication of 142 kms, 3LCDM over WDM performs better compared to traditional technique of NRZ over WDM
the project is done using Optisystem