BER Summary (DOCSIS 4.0 Upstream)

The BER Summary trace shows the Bit Error Ratio (BER) and Codeword Error Ratio (CWER).

A displayed value of "***", "-780dB" or "-999" means no data is available.

BER/CWER

BER/CWER measurements only show when BER Analysis is selected under the Format tab.

Randomization Seed (under Format tab) should be set correctly to properly decode the codewords (note that setting the randomization seed to 0x00 is equivalent to turning the randomizer/scrambler off).

Bits Before LDPC: You can accumulate bit counts by enabling measurement averaging (MeasSetup > Average > RMS or RMS Exponential). The Pause Measurement after Bit Count feature uses the Bits before LDPC count.
Bit Errors Before LDPC: Bit error count before LPDC. After LPDC, codeword errors are measured instead of bit errors.
BER Before LDPC: Ratio of bit errors to total bits before LPDC. After LPDC, codeword errors are measured instead of bit errors.
Num Codewords: Total number of codewords processed for CWER.
CW Errors Post LDPC: Codeword Error count after multiple iterations of the LDPC decoder and before the BCH decoder.
CWER post LDPC: Codeword error ratio after multiple iterations of the LDPC decoder and before the BCH decoder.
Average LDPC iterations: Average number of LDPC iterations used over all codewords.
Max LDPC iterations: Maximum number of LDPC iterations used over all codewords. The maximum number of iterations used in decoding is 20.

Codeword Summary by Type (Size)

This table displays the NumCodeWords and CWErrorsPostLDPC data in greater detail, organized by codeword type, as defined in Section 7.4.3 of the DOCSIS 3.1 Physical Layer Specification.