Rolled up FEC Channel issues only apply to OFDM and OFDM/A FEC parameters. OFDM FEC parameters have profiles, and OFDMA FEC parameters have an IUC. During the issue generation phase, the NXT Engine performs computations on various KPIs that are based on the configured thresholds. This determines the modems that have issues, and reports them in the appropriate issue group. These computations typically occur at the channel level for SC-QAM and at the sub-carrier level for OFDM/A parameters.
For OFDM/A FEC parameters, the issues occur at the "profile" or "iuc" level rather than at channel level. So, computation of issues for such parameters will be done at the per-profile / per-IUC level. For reporting, it is useful to report the Issue at the channel level rather than at the "per-profile/ per-IUC" level. Therefore, ServAssure NXT rolls up the individual per-profile/iuc FEC values to a channel level and reports these issues at the channel level. The example below shows rolled up values in the Channel CCER (%) column.
Rolled up values only apply to these OFDM and OFDM/A FEC parameters:
- Channel CER (%)
- Channel CCER+CER (%)
- Channel CCER (%)