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Transport aspects 2

Floor Minimum Nominal Maximum Ceiling
ODUj signal M m=128M
Cm,min cm cm cm Cm,max
ODUflex(CBR) ODUflex(CBR) dependent
– ODUflex(CPRI 4) 1 128 8964 8964.833 8965.909 8966.985 8967
– ODUflex(CPRI 5) 1 128 14343 14343.734 14345.455 14347.176 14348
– ODUflex(CPRI 6) 2 256 17929 17929.667 17931.819 17933.971 17934
– ODUflex(CPRI 7) 2 256 28687 28687.467 28690.910 28694.353 28695
– ODUflex(CPRI 8) 2 256 29583 29583.950 29587.501 29591.051 29592
– ODUflex(CPRI 9) 3 384 35500 35500.740 35505.001 35509.262 35510
– ODUflex(CPRI 10) 5 640 71001 71001.481 71010.002 71018.523 71019

7.2 Multiple CPRI client signal mapping using GFP-T

Transparent generic framing procedure (GFP-T), as defined in clause 8 of [ITU-T G.7041], can be used to
carry CPRI clients. The GFP multiplexing facility described in clause 6.1.2.1.3.2 of [ITU-T G.7041] provides a
means to carry multiple CPRI clients of the same rate within an OPUk or an OPUflex(GFP) carrier. These two
facilities can be combined to yield a method to map multiple CPRI clients (Options 1 to 6) into an ODU2
carrier stream as per clause 17.4 of [ITU-T G.709]. The CPRI clients being mapped are synchronous to each
other. The ODU2/OTU2 clock is made to be synchronous to the CPRI clients. The selection of which CPRI
client provides a reference clock to the OTU2 clock is outside the scope of this document. Figure 7-1 shows
the mapping of ynchronous CPRI clients into a synchronous OTU2.

Figure 7-1 – Mapping of synchronous CPRI clients into a synchronous OTU2
The relationship between the OTU2 bit rate and the CPRI client bit rate is given by:

CPRI_BitRate = k * OTU2_BitRate * (79/1377)
The value of the scaler 'k' for CPRI options 1 to 6 are shown in Table 7-10.

Table 7-10 – Scaler 'k' of CRPI options 1 to 6

CPRI client k
Option 1 (614.4 Mbps) 1
Option 2 (1228.8 Mbps) 2
Option 3 (2457.6 Mbps) 4
Option 4 (3072.0 Mbps) 5

Option 5 (4915.2 Mbps) 8
Option 6 (6144.0 Mbps) 10

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