Page 795 - 5G Basics - Core Network Aspects

Transport aspects 2

Figure 10-22 – VFRB format (in case only vectored bands 1 and 3 are
requested by the VCE)

The format of the VBB is presented in Figure 10-23. Each VBB starts from an 8-bit VBB_ID field, followed by
concatenated VF blocks, and ends with a pad of zero, two, four or six bits to fit the length of the VBB to an
integer number of bytes (odd number of padding bits is not applicable). The three MSBs of the VBB_ID field
shall comprise the number of the vectored band (000 for VBB-0, 001 for VBB-1, … up to 111 for VBB-7). The
five LSBs of the VBB_ID field shall be set to '0' and be reserved for ITU-T. The VF blocks shall be
concatenated in a VBB in ascending order: the VF block 0 is the one that contains VF samples for the
subcarrier with lowest index and shall be transmitted first. The block of VBB data are mapped to the bytes
according to Figure 10-23.

F_block = or 2 4
MSB LSB MSB MSB MSB MSB MSB MSB MSB MSB
Byte appingm Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8 Last byte

VF ample s F_block VF samples 2 or 4 VF samples
b it equences VBB_ID EXP in VF lock 0b Block ID EXP in VF lock b 1 Pad
F_block 2 × × F_block × 2 × 0, 2, 4, or
8 bits 4 bits (B_M – B_L + 1) bits 4 bits 4 bits (B_M – B_L + 1) bits 6 bits
VF_block_0 VF_block_1

VF_block_ j= (4 + F_block × 2 × ( B_M(vb,eb) – B_L(vb,eb) + 1)) bits
(4 + (4 + Σ VF_block_j )) = ( 20 + (8 + F_block × 2 × (Σ B_M ( , ) vb eb – B_L ( ,vb eb ) + 1))) bits without padding
(4 + N_block ( ) (8 + vb × F_block × 2 L_w× )) bits with padding
F_block = 1
MSB LSB MSB MSB MSB MSB MSB MSB MSB MSB
Byte appingm Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8 Last byte

VF S ample s 1 VF sample 1 VF samples 1 VF samples
b it equences VBB_ID EXP in VF lock 0b EXP in VF lock b 1 EXP in VF lock b 2 Pad
F_block × 2 × F_block 2 × × F_block 2 × × 0, 2, 4, or
8 bits 4 bits (B_M – B_L + 1) bits 4 bits (B_M – B_L + 1) bits 4 bits (B_M – B_L + 1) bits 6 bits
VF_block_0 VF_block_ 0 VF_block_ 0

( + N_block × ( + 2 4 × L_w )) bits
8
G.9701(14)-Cor.1(15)_F10-23

Figure 10-23 – VBB format depending on F_block

All fields of the VBB presented in Figure 10-23 shall be transmitted MSB first; the MSB of the VBB_ID shall
be the MSB of the first byte of the VBB field, as shown in Figure 10-22.
The format of the VF block is defined in clause 10.3.2.4.2.
In case F_block = 2 or 4, a Block_ID shall be pre-pended to each VF block, starting with VF block number 1.
A Block_ID shall not be inserted just before VF block 0. The Block_ID shall be four bits long, and shall

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