Page 878 - 5G Basics - Core Network Aspects

2 Transport aspects

Figure 11-11 – Voltage across the load without access cabling

Figure 11-12 – Voltage across the load with access cabling inserted
11.4.1.2.9.2 Reporting of downstream FEXT coupling coefficients (Xlogpsds)

Xlogpsds values are computed by the VCE, and reporting shall be according to the description in this clause.
The exact method used by the VCE to estimate the values of Xlogpsds is vendor discretionary.

The downstream FEXT coupling coefficients Xlogdsi,k (n × Δf) for current line i, shall be reported to the
management entity upon request at least for all lines k in the vectored group and subcarrier indices n for
which FEXT from line k into line i is estimated or cancelled in the downstream direction with the subcarrier
index n specified by:
n  start _ subcarrier _ index  m XLOGGds: m 0 ... floor   stop _ subcarrier _ index  start _ subcarrier _ index  XLOGGds/ 
bands

In this description,

– disturber line k is identified by its VCE_port_index (see clause 11.4.6.1.2) within the same vectored
group as the current line i,
– each frequency band shall be represented by a pair of (start_subcarrier_index,
stop_subcarrier_index),
NOTE 1 – The start_subcarrier_index and stop_subcarrier_index may not coincide with the edges of the bands in
which FEXT is estimated or cancelled. The reported start_subcarrier_index corresponds with the first reported
subcarrier for the band. The reported stop_subcarrier_index corresponds with the last reported subcarrier for the
band.
– for each frequency band XLOGGds is the subcarrier group size used.

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