PMD leads to pulse broadening and inter-symbol interference, increasing the bit error rate at high data rates. Dispersion compensation, PMD mitigation. To ensure performance under high load and high speed, the network layer needs. line coding, and further dispensation of received signal. In a communication system, the receiver side BER may be affected by transmission channel noise, interference, distortion, bit synchronizat on problems, attenuation, wireless multipath fading, etc. The BER can be considered as an approximate. Bit Error Rate (BER) is a measure of signal integrity in data transmission systems, typically defined as the average ratio of the number of erroneously received bits to the total number of bits transmitted.