VSC6134
Datasheet
2.7
Forward Error Correction (FEC) Encoder
The following terms are used throughout this section.
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An RS codeword consists of 25 bytes (symbols): 239 data bytes and 16 parity bytes.
An OTU row consists of 16, byte-interleaved RS codewords for a total of 4080 bytes. The first
16 bytes are digital wrapper overhead (DWOH).
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An OTU frame consists of 4 OTU rows. The overhead of the first row contains the OTU frame
alignment signal.
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Standard FEC (SFEC) is Reed Solomon encoding.
Enhanced FEC (EFEC) is a proprietary encoding.
The block diagrams for the FEC encoder block are shown in Figure 14, page 79 and Figure 15, page 80.
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VMDS-10185 Revision 4.0
July 2006
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
