24
When FEC is enabled, you can change the X and Y axes to the supported graph combinations
where instant and accumulated bit counts are supported and can see the results of the
measurements in the details section. SER measurements are also supported in FEC mode;
corrected codewords with symbol error distribution are displayed.
A:
FEC/SER graphs
–
B:
Graph Auto Scale
–
C:
History Navigation
–
D:
Measurement Filtering
E:
Graph Display Measurements Selection
–
F:
Link Selection
–
G:
Timer/Continuous Mode
H:
Stop/Start FEC/SER
–
I:
Details panel
Instant and Accumulated Measurement
Measurement Description
Corrected Bit Count
Sum of corrected “0” and “1” bits after decoding.
Corrected Zero Count
Number of “0” bits that were corrected to be “1” bits after decoding.
Corrected One Count
Number of “1” bits that were corrected to be “0” bits after decoding.
Processed Codeword Count
Total number of codewords, correctable and uncorrectable processed
by the decoder.
Corrected Codeword Count
Number of codewords (FEC blocks) that were corrected by the decoder,
which means the number of codewords that were determined to have a
correctible magnitude of symbol errors.
Uncorrected Codeword Count
Total number of codewords that were deemed uncorrectable by the
decoder, which means number of codewords that were determined to
have more than the correctible magnitude of symbol errors.
Uncorrected Codeword Rate
Number of uncorrected codewords compared to the number of
processed codewords.
FEC Symbol Error Rate
Number of symbol errors divided by the total number of processed
symbols.
FEC Symbol Error Count
Total number of symbol errors processed by the decoder.
Pre-FEC BER
Raw and unframed ratio of incorrect bits (Bit Errors/Total Bits) on a
channel-by-channel basis.
Post-FEC BER
Total number of bit errors remaining after real FEC decoding divided by
the total number of received bits.
Figure 44: Measurement display
Table 5: Instant and Accumulated Real Hardware FEC Measurements
