Page 1288 - 5G Basics - Core Network Aspects
P. 1288
2 Transport aspects
. 0 340362 for y 40 ppm
0.268908 for y 0 ppm (I-18)
. 0 878177 for y 40 ppm
In addition, stuff ratios of −2 and +1 are obtained for frequency offsets of −113.65 ppm and 83.30 ppm,
respectively. The range of frequency offset that can be accommodated is approximately 197 ppm. This is
50% larger than the range that can be accommodated by a +1/0/−1 justification scheme (see above), and is
due to the additional positive stuff byte.
ODU2 into ODU3 multiplexing
The ODU2 nominal client rate is (see clause 7.3):
239
S 4 ( R 16 ) (I-19)
237
The ODU3 nominal frame time is:
( 3824 )( ) 4
T (I-20)
239 ( 16R )
236 16
The fraction p is 0.25. Inserting into equation I-3 produces:
239 ( 3824 )( ) 4
4 R 16 3808 N (I-21)
237 239 ( 16 R ) 4
236 16
Simplifying and solving for produces:
236
( 15296 ) 4 N 15232 (I-22)
237
As before, let = 1 + y, where y is the net frequency offset (and is very nearly equal to yc − ys for client and
server frequency offset small compared to 1). Then:
236 236
( 15296 ) 15232 4 N ( 15296 y )
237 237 (I-23)
4 N . 0 5400844 15231 . 459916 y
The number of fixed stuff bytes N is zero, as given in clause 19.5.3. The client and mapper frequency offsets
are in the range 20 ppm, as given in clause 7.3. Then, the net frequency offset y is in the range 40 ppm.
Inserting these values into equation I-23 gives for the range for :
. 0 0691740 for y 40 ppm
. 0 540084 4 for y 0 ppm (I-24)
. 1 149343 for y 40 ppm
In addition, stuff ratios of −2 and +1 are obtained for frequency offsets of −95.85 ppm and 101.11 ppm,
respectively. As above, the range of frequency offset that can be accommodated is approximately 197 ppm,
which is 50% larger than the range that can be accommodated by a +1/0/−1 justification scheme (see
above) due to the additional positive stuff byte.
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