Page 1245 - 5G Basics - Core Network Aspects

Transport aspects 2

 ODUk_ nom_ bit _ rate  Number _ of _ GMP_ blocks _ in _ ODTUCn. ts 
c m, nom      (20-3)
 ODTUCn _1. nom_ bit _ rate M 
 1 ODUk_ bit _ rate _ tolerance 
c m min,  c m, nom     (20-4)

 1 ODTUCn _1. bit _ rate _ tolerance 
 1 ODUk_ bit _ rate _ tolerance 
c m max,  c m, nom     (20-5)

 1 ODTUCn _1. bit _ rate _ tolerance 
C  floor c  (20-6)
m , min m , min
C  ceiling c  (20-7)
m , max m , min
n  8 (20-8)
 ODUk_ nom_ bit _ rate  Number _ of _ GMP_ blocks _ in _ ODTUCn. ts 16 
c n, nom      (20-9)
 ODTUCn _1. nom_ bit _ rate 
 1 ODUk_ bit _ rate _ tolerance 
c  c    (20-10)
n min, n, nom  1 ODTUCn _1. bit _ rate _ tolerance 
 
 1 ODUk_ bit _ rate _ tolerance 
c n max,  c n, nom     (20-11)

 1 ODTUCn _1. bit _ rate _ tolerance 
C  floor c  (20-12)
, n min , n min
C  ceiling c  (20-13)
, n max , n min
Cm,min, Cn,min (n=8), Cm,max and Cn,max (n=8) values represent the boundaries of ODUk/ODTUCn.M ppm offset
combinations (i.e., min. ODUk/max. ODTUCn.M and max. ODUk/min. ODTUCn.M). In steady state, given
instances of ODUk/ODTUCn.M offset combinations should not result in generated Cn and Cm values
throughout this range but rather should be within as small a range as possible.

NOTE – Under transient ppm offset conditions (e.g., AIS to normal signal), it is possible that Cn and Cm values outside
the range Cn,min to Cn,max and Cm,min to Cm,max may be generated and a GMP de-mapper should be tolerant of such
occurrences. Refer to Annex D for a general description of the GMP principles.

20.5.1 Mapping ODUk into ODTUCn.M

Groups of M successive 16-byte words of the extended ODUk (k = 0, 1, 2, 2e, 3, 4, flex) signal are mapped
into a group of M successive 16-byte blocks of the ODTUCn.M payload area under control of the GMP
data/stuff control mechanism. Each group of M 16-byte blocks in the ODTUCn.M payload area may either
carry M ODUk 16-byte words, or carry M stuff 16-byte words. The value of the stuff bytes is set to all-0s.

The groups of M 16-byte blocks in the ODTUCn.M payload area are numbered from 1 to 952.
The ODTUCn.M payload 16-byte numbering for GMP M 16-byte (m-bit) blocks is illustrated in Figure 20-11.
In row 1 of the ODTUCn.M multiframe the first M 16-byte blocks will be labeled 1, the next M 16-byte
blocks will be labeled 2, etc.

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