Page 688 - 5G Basics - Core Network Aspects

2 Transport aspects

(connected to line n) over an interface here called ε-c-n (e.g., to set precoder coefficients for vectoring).
The information contained in the vectoring feedback channel (VFC-n) enables the VCE to determine the
precoder coefficients. The vectoring feedback information is conveyed from the FTU-R to the VCE over the
U interface to the FTU-O and then over the VFC to the VCE. Inside the DPU, the management entity (ME)
conveys the management information (over an interface here called ε-m) to the VCE.
The DRA coordinates the downstream and upstream transmission opportunities over the vectored group.
The allocation of downstream and upstream transmission opportunities may be static (i.e., constant over
time as set by the ME) or may be dynamic (i.e., variable over time, depending on the traffic needs and
within the bounds set by the ME and the PCE). The DRA receives dynamic resource reports (DRRs) from the
Layer 2+ functionality for each of the lines in the vectored group (shown as DRRds-n and DRRus-n). The
DRRus is passed from the NT to the DRA over the γR, U-R, U-O and γO reference points. Inside the DPU, the
ME conveys the management information (over an interface here called DRA-m) to the DRA.

The management information conveyed over the DRA-m interface imposes bounds on the allocation of
upstream and downstream transmission opportunities per subscriber line within the vectored group.
NOTE – The bounds imposed by the ME on the DRA may be related to service level agreements (SLA).
The PCE may further impose bounds on the allocation of downstream and upstream transmission
opportunities using information about traffic needs per line and environmental information within the DPU
related to power dissipation, e.g., temperatures inside the DPU and available power supplies. The
necessary management information (e.g., temperature limits and power dissipation targets) is conveyed
over the PCE-m interface. Based on this information, the PCE tracks the power consumption of the DPU and
limits the allocation of transmission opportunities per subscriber line, in both upstream and downstream
directions, accounting for various criteria including the traffic need and environmental information.

The LinkState-n and BAT-n primitives are used for low power operation.
Figure 5-3 provides an overview of the reference model of the information flows within NT-n. The NT
reference model represents a single FTU-R.
All functionality related to the transmission and reception with synchronous time-division duplexing (STDD)
over the vectored group is contained inside the FTU-R.

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