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Transport aspects 2
Figure 8-1 – OPU2r overhead
8.1.1 OPU2r overhead definition
8.1.1.1 OPU2r payload structure identifier (PSI)
A one-byte PT signal is defined in the PSI[0] byte of the payload structure identifier to indicate the
composition of the OPU2r signal. The code points are defined in Table 8-1. The remaining 255 PSI bytes are
reserved.
Table 8-1 – Payload type code points for OPU2r
MSB LSB
Hex code Interpretation [CPRI]
1234 5678
1000 0000 80 Option 3 multiplexing structure
1000 0001 81 Option 4 multiplexing structure
1000 0010 82 Option 5 multiplexing structure
NOTE – These three code values are from the reserved codes for proprietary use. Refer to Annex A of [ITU-T G.806] for more
information on the use of these codes.
8.1.1.2 OPU2r mapping specific overhead
An OPU2r multiframe identifier (OMFI) byte is defined in row 4, column 16 of the OPU2r overhead, see
Figure 8-2. The value of bits 7 to 8 of the OMFI byte will be incremented each OPU2r frame to provide a
3-frame multiframe for the multiplexing of CPRI signals into the OPU2r.
NOTE – It is an option to align the OMFI = 0 position with MFAS = 0 position every 768 (the least common multiple of 3
and 256) frame periods.
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