Page 991 - 5G Basics - Core Network Aspects

Transport aspects 2

For the settings of L2.1 upstream RMC transmission schedule and upstream transmission parameters in the
L2.1-Entry-Request eoc command:
• L2.1_ETR ≥ L2.1_ETR_min_eoc;
• L2.1_NDR ≤ L2.1_NDR_max;

• L2.1_Exit_ETR ≥ L2.1_Exit_ETR_min;
• L2_TARSNRM ≤ SNRM ≤ L2.1_MAXSNRM.
For the settings of L2.1 downstream RMC transmission schedule and downstream transmission parameters
in L2.1-Entry-Request eoc command:
• L2.1_ETR ≥ L2.1_ETR_min_eoc;
• L2.1_NDR ≤ L2.1_NDR_max;
• L2.1_Exit_ETR ≥ L2.1_Exit_ETR_min;

• BDR ≥ L2.1_BDR_min.
For the settings of L2.1 downstream transmission parameters in the L2.1-Entry-Confirm eoc response:
• L2.1_ETR ≥ L2.1_ETR_min_eoc;
• L2.1_NDR ≤ L2.1_NDR_max;

• L2.1_Exit_ETR ≥ L2.1_Exit_ETR_min;
• L2_TARSNRM ≤ SNRM ≤ L2.1_MAXSNRM;
• bi values shall be not greater than the bi values proposed in the L2.1-Entry-Request eoc command;
• BDR ≥ L2.1_BDR_min.
For both the upstream and downstream transmission parameters:

• DTU size restriction:
NDTU + Q × RFEC ≤ (N-1) × BDR,
where N is the number of active TDD frames per superframe in L2.1 (see clause 13.4.1.1).

NOTE 1 – This requirement on the L2.1 framing parameters implies the one-way latency without
retransmission in the L2.1 link state does not exceed the duration of 1 superframe (TSF).

• 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.

• The control parameter delay_max during L2.1 shall be set to delay_max = max(2×TSF, DELAYMAX).
This setting allows at least two retransmission attempts with any selected value of N.RFEC/NFEC ratio
≥ rnratio_min.
• SNRM ≥ L2_TARSNRM for all active data subcarriers.
• SNRM_RMC ≥ TARSNRM-RMC for all RMC subcarriers.

Within the above constraints, for upstream, the FTU-O and VCE shall jointly select the values in the L2.1-
Entry-Request eoc command so as to optimize in the priority specified:

1) While keeping same PSD as in L0, the FTU-O determines via a vendor discretionary method
– the set of L2.1 subcarriers
– the bit loading table
– the framing parameters
– the number of RMC symbols per superframe (N)

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