Pre-FEC and Post-FEC BER Measurement

To further enhance the cable qualification process, performing both pre-FEC and post-FEC Bit Error Rate (BER) measurements is essential:

  • Pre-FEC BER Measurement: This measures the bit error rate before any error correction is applied. It provides a raw assessment of the signal quality and the inherent error rate of the transmission.

  • Post-FEC BER Measurement: This measures the bit error rate after forward error correction has been applied. It shows the effectiveness of the FEC in correcting errors and provides a more realistic view of the actual performance experienced by the end user.

By including both pre-FEC and post-FEC BER measurements, you can gain a comprehensive understanding of the cable’s performance and the effectiveness of the error correction mechanisms.

Setup

  1. Test duration

Method

  1. Enable FEC on TX ports.

  2. Clear FEC counters.

  3. Measure pre-FEC BER and post-FEC BER on RX ports.

  4. Report the time-series data of the pre-FEC BER and post-FEC BER.

Output Example

FEC BER Example

Fig. 4 FEC BER Example