Page 863 - 5G Basics - Core Network Aspects

Transport aspects 2

11.4.1.1.11 Signal-to-noise ratio margin for the RMC (SNRM-RMC)

The SNRM-RMC is the signal-to-noise ratio margin of the RMC. It is defined in clause 9.8.3.4.
The SNRM-RMC shall be measured over all subcarriers assigned to the RMC in RMC symbols for which bi > 0
in the transmission direction.
The measurement of SNRM-RMC may be updated autonomously and shall be updated on request during
the showtime (L0, L2.1N, L2.1B and L2.2 link states). The SNRM-RMC shall be sent to the far-end FTU during
the initialization and shall be sent on request to the near-end ME at any time. The near-end ME shall send
the SNRM-RMC to the far-end ME on request during the showtime (L0, L2.1N, L2.1B and L2.2 link states).

The SNRM-RMC shall use the same representation as defined for SNRM in clause 11.4.1.1.10.
The value during the L0 link state shall be reported as SNRM-RMC in the DPU-MIB.

The value during the L2.1N, L2.1B and L2.2 link states shall be reported as L2_SNRM-RMC in the DPU-MIB.
During the L0 link state, downstream and upstream SNRM-RMC values are reported by the FTU-O as
SNRM-RMC in the DPU-MIB. During the L2.1N, L2.1B or L2.2 link state, SNRM-RMC values of the last update
in the L0 link state are available in the DPU-MIB.

During the L2.1N, L2.1B or L2.2 link state, downstream and upstream SNRM-RMC values are reported by
the FTU-O as L2_SNRM-RMC in the DPU-MIB. During the L0 link state SNRM-RMC values of the last update
in the L2.1N, L2.1B or L2.2 link state are available in the DPU-MIB.

During the L3 link state (see Figure 12-1), the values of SNRM-RMC, L2_SNRM-RMC at the last update are
available in the DPU-MIB, until the FTU-O transitions to the O-INIT/HS state, at which time the values may
become "undetermined".

11.4.1.1.12 Net data rate in L2.1 (L2.1_NDR)
The status parameter net data rate in L2.1 link state (L2.1_NDR) is defined in Table 13-13 as

L2.1_NDR = L2.1_DPR – L2.1_DPReoc,
where the L2.1_DPR represents the DTU payload rate (defined in Table 13-13) during the L2.1N or L2.1B
link state and the L2.1_DPReoc the L2.1N or L2.1B link state eoc data rate (defined in Table 13-13), that shall
be used for the purpose of this calculation.

The L2.1_NDR shall be calculated by the receiver at the entry into the L2.1N or L2.1B link state and updated
during the L2.1N and L2.1B link states upon OLR using equations for L2.1_DPR presented in Table 13-13. It
shall not be updated during the L0, L2.2, and L3 link states.

The valid values for L2.1_NDR are all integers from 0 to the configured value of NDR_max
(see clause 11.4.2.2).

The L2.1_NDR shall be represented as a 32-bit unsigned integer expressing the value of L2.1_NDR in kbit/s.
This data format supports a granularity of 1 kbit/s.

32
A special value 2 -1 indicates that the parameter is undetermined. All other values are reserved by ITU-T.
The DPU derives the DPU-MIB reporting parameters L2.1_NDR from L2.1_NDR. During the L2.1 link state,
downstream and upstream actual L2.1_NDR values are reported in the DPU-MIB. During the L0 or L2.2 link
state, downstream and upstream L2.1_NDR values of the last update of L2.1_NDR in the L2.1N or L2.1B link
state, are available in the DPU-MIB.

During the L3 link state (see Figure 12-1), the values of the last update are available in the DPU-MIB, until
the FTU-O transitions to the O-INIT/HS state, at which time the values may become "undetermined".

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