Optical Network Design and Implementation

WDM Characteristics and Impairments to Transmission

The bit error rate (BER) is a ratio of error bits to total transmitted bits. Typical values are 10^–12 BER for SONET and 10^–15 for next-generation long-haul transport equipment. The value 10^–15 is 1 error bit in 10¹⁵ bits, which equates to one error in 11.6 days for a 10-Gbps signal. The eye pattern in Figure 4-30 is a visual depiction an OC-192/STM-64 waveform. It consists of the waveform for each wavelength overlaid on one screen. The eye pattern display allows for quick verification of signals that meet performance specifications. In the display, the 1 signals are above the center point, and the 0 signals are below the center point. An eye pattern is a sampling oscilloscope display in which ...