RF Spectral Analysis for SONET Framing Recognition and Performance Monitoring

We have experimentally demonstrated a novel framing recognition and performance monitoring scheme for SONET signal using the RF spectral analysis and taking advantages of the intrinsic data structure of the SONET signal itself. This scheme does not require access to individual bits or any recovered clock or data information. It can recognize SONET framing sequences and generate framing pulses correspondingly. It also provides an analog indicator that varies monotonically with the bit error ratio (BER). It is shown both theoretically and experimentally that this analog indicator actually correlates with the channel Q factor by a simple relation. The proposed scheme, in principle, can be scaled to OC-192 and even higher data rates.