Page 860 - 5G Basics - Core Network Aspects

2 Transport aspects

NOTE 1 – As a result of this definition, EFTR ≤ DPR (see Table 9-21).
NOTE 2 – DTUs that have been detected to be in error and DTUs that exceed delay_max do not cross the  reference
point at the receiver side.
The EFTR shall be calculated by the receiver in showtime during L0 link state only.

The EFTR shall be calculated for every complete second the FTU is in the showtime L0 link state. Only for
these seconds, the EFTR is defined. For other seconds, the EFTR is not defined. The EFTR is not a status
parameter directly reported to the ME, but is used in the definition of related parameter EFTR_min.
NOTE – EFTR is not defined in L2.1N, L2.1B, L2.2 and L3.

11.4.1.1.6 Minimum error-free throughput (EFTR_min) parameter
The performance monitoring parameter minimum error-free throughput (EFTR_min) is defined as the
minimum of the EFTR observed in the seconds since the last reading of the EFTR_min, excluding the
following seconds:
• seconds in which EFTR is not defined;
NOTE 1 – EFTR_min will be close to the DPR at instances of high data throughput and when TPS_TESTMODE is
enabled. At instances of no data throughput, EFTR_min will be at the maximum of the eoc data rate and the
background normal DTU rate for performance monitoring (see clause 8.3.1).
The EFTR_min shall be measured in showtime by the receiver. Reading by the FME at the FTU-O of the far-
end EFTR_min shall be via an eoc command over the U interface. Reading by the FME at the FTU-O of the
near-end EFTR_min shall be from the near-end receive PMS-TC over the PMS-TC_MGMT interface.

The valid values are all integers from 0 to the maximum of the valid values of the maximum DPR.
The performance monitoring parameter EFTR_min shall be represented as a 32-bit unsigned integer
expressing the value of ceiling(EFTR_min 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 previous value of EFTR_min shall be reported if no EFTR measurement has been done since the last
reading of EFTR_min.
NOTE 2 – The above requirement covers the case where two retrievals of EFTR_min over the eoc take place in less
than one second, and in which no new EFTR measurement is available, since the EFTR is only updated on one second
interval.
Although this parameter EFTR_min is reported via the management counter read eoc command, this
performance monitoring parameter is not a counter.
The parameter reported to the DPU-MIB, MINEFTR, is defined as the minimum of the retrieved EFTR_min
values observed over the 15 min or 24 hour accumulation periods.
The FME at the FTU-O shall retrieve the far-end EFTR_min, to calculate the far-end MINEFTR as defined in
the DPU-MIB. The FME at the FTU-O shall retrieve the near-end EFTR_min to calculate the near-end
MINEFTR, as defined in the DPU-MIB. If the 15 min or 24 h interval contains only seconds with undefined
EFTR, the related MINETFR shall be set to 0.

NOTE 3 – The frequency of retrieval for both near-end and far-end is left to the implementation, as necessary for
accurate monitoring.
The upstream MINEFTR value shall be reported to the DPU-MIB as a near-end value.

The downstream MINEFTR value shall be reported to the DPU-MIB as a far-end value.

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