Page 797 - 5G Basics - Core Network Aspects

Transport aspects 2

MSB LSB MSB LSB MSB LSB MSB LSB MSB LSB MSB LSB
Byte appingm Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Last byte

VF Sample First VF sample First VF sample Second VF sample Second VF sample
b it equences EXP x component y component x component y component

4 bits B_M B_L – +1 bits B_M – B_L + 1 bits B_M – B_L + 1 bits B_M B_L – +1 bits

First vectoring feedback ( VF ) sample Second vectoring feedback ( VF ) sample
F_block vectoring feedback ( VF ) samples

VF block consists of (4 + F_block × 2 × (B_M – B_L + 1)) bits
G.9701(14)-Cor.1(15)_F10-24

Figure 10-24 – Format of a VF block
10.3.2.4.3 Vectoring feedback channel data rate (informative)

In case F_block = 2 or 4, the number of bytes in the VBB-vb without padding, following from Figures 10-22,
10-23 and 10-24 is:

 N _ block (vb ) 1  
N _VBB    ceilingvb   4   8 F _block  2   _ MB (vb ,eb )  B _ L (vb ,eb ) 1   8/ 
  eb 0    

where B_M(vb,eb) represents the B_M parameter for the VF block number eb of vectored band number vb,
B_L(vb,eb) represents the B_L parameter for the VF block number eb of vectored band vb.
In general, this value is not fixed but may be different from one vectoring feedback report to the next,
depending on the exact values of the VF samples. If padding (see Table 10-9) is used, the number of bytes
in the VBB-vb only depends on the vectoring feedback control parameters and not on the values of the VF
sample values:

N _VBB    ceilingvb   4  N _block (vb )   2 L _ w  F _block  8   8/
In case F_block = 1, padding is used and the number of bytes in the VBB-vb only depends on the vectoring
feedback control parameters and not on the values of the VF sample values:

N _VBB    ceilingvb  8 N _ block (vb )  4(  2  L _ w (vb )) 


 8 
The N_VFRB can be calculated as:
N _band 1
vb
N _VFRB 1   report   Nvb _VBB  
vb 0
where report(vb) =1 if the VBB-vb is included in the VFRB (i.e., L_w > 0 for band number vb), and report(vb)
= 0 if the VBB-vb is not included in the VFRB (i.e., L_w = 0 for band number vb).
The vectoring feedback channel data rate (VFCDR) for transmission of the VFRB for each sync symbol is:

VFCDR  8 N _VFRB  f DMT /(T  M SF  )
F
where f is the symbol rate (in symbols/s) defined in clause 10.4.4.
DMT
The vectoring feedback channel data rate is not constant when padding is not used. In that case, it varies
since N_VFRB varies from vectoring feedback report to vectoring feedback report.

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