Page 967 - 5G Basics - Core Network Aspects

Transport aspects 2

2) A TDD frame that has a number of symbol periods (MF) equal to the value assigned for the active
lines,
3) The number of downstream symbol positions (Mds) that is the same as the value assigned for the
active lines in a TDD frame,
4) Seeds for the quadrant scrambler that are different for all lines,
5) An IDS length that is the same as the length assigned for the active lines, where each line gets a
particular IDS value determined by the VCE,
6) The number of SOC symbol repetitions, RS, that is the same for all joining lines,
7) The number of initialization data symbols in the downstream direction (sds) that is the same for all
joining lines,
8) The positions of upstream and downstream RMC symbols that are equal to the values assigned for
the active lines,
9) Superframe timing of all initializing lines that is aligned with the superframe timing of active lines,
as described in clause 10.8.
12.3.7 Channel initialization policies

The method used by the receiver to select the values of transceiver parameters described in this clause is
implementation dependent. However, within the limit of the net data rate achievable by the local PMD, the
selected values shall meet all of the constraints communicated by the transmitter prior to the end of the
Channel Analysis & Exchange phase, including:
• ETR ≥ ETR_min_eoc.
• NDR≤ NDR_max.
• Impulse noise protection

– at least against a combined threat of worst-case REIN impulses as described by the
retransmission control parameters INP_min_rein and iat_rein_flag and of worst-case SHINE
impulses as described by the retransmission control parameter INP_min_shine, and
– within the latency bounds defined by the control parameter delay_max
– within the minimum RFEC/NFEC ratio rnratio_min
• SNRM ≥ TARSNRM

• SNRM_RMC ≥ TARSNRM-RMC.
If within these constraints, the receiver is unable to select a set of configuration parameters, then the
transmitter shall enter the SILENT state instead of the showtime state at the completion of the initialization
procedures.

Within those constraints, the receiver shall select the values so as to optimize in the priority specified by
the channel-initialization policy (CIpolicy). The channel-initialization policy applies only for the selection of
the values exchanged during initialization, and does not apply during the showtime.

The following channel-initialization policy is defined:
– Policy ZERO
If CIpolicy = 0, then:
For downstream,
1) Maximize the NDR until the limit of NDR_max
For upstream,

1) Maximize the NDR until the limit of NDR_max
2) Maximize SNRM until the limit of MAXSNRM
3) Minimize excess margin with respect to MAXSNRM through gain adjustments (see
clause 10.2.1.5.2)

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