Page 873 - 5G Basics - Core Network Aspects

Transport aspects 2

received by the FTU-R. These signals are referred to the U-O and U-R reference points, respectively. SATN
shall be computed so as to remove the power of the crosstalk compensating precoder signals downstream.

The SATN_DS, shall be computed by the VCE using the following reference formula:
SATN_DS = Direct_TXpower_dBm_DS – RXpower_dBm_DS
The FTU-R shall measure and report the received signal total power defined as:

 
RXpower_dB m_DS 10 log 10   Received_s ubcarrier_ power_mW_D ( S ) i 


 i MEDLEYds ,gi 0   ,
where {MEDLEYds, gi≠0} denotes all subcarriers of the MEDLEYds set that have gi≠0, and
Received_subcarrier_power_mW_DS(i) is the received signal total power at the U-R reference point on
subcarrier i expressed in milliWatts, assuming the receiving FTU presents a load impedance to the network
of 100 Ohms resistive (see Note 1).

NOTE 1 – In actual implementations, the receiving FTU load impedance may deviate from 100 Ohms resistive.
The FTU-R shall average the received signal total power over at least 256 symbols (consecutive or non-
consecutive). The received signal total power shall only be measured in time periods during reception of
RMC symbols or data symbols in the NOI at the symbol positions specified by the MNDSNOI value.

The VCE, in cooperation with the FTU-O, shall refer the Direct_TXpower_dBm_DS to the U-O interface,
assuming the network input impedance is 100 Ohms resistive (see NOTE 2).

NOTE 2 – In actual deployments, the network/loop input impedance may deviate from 100 Ohms resistive.
Direct_TXPower_dBm_DS shall be computed as:
  Pdirect _ Z  ' 

Direct _TX_power_ dBm_DS 10  log 10   f SC 10 (MREFPSD i /10)  i 

 

 i  MEDLEYds ,gi 0   Ptotal _ Z i '  
Where fSC is the subcarrier spacing in Hz defined in clause 10.4.2, MREFPSDi is the value of MREFPSD in
dBm/Hz, Pdirect_Zi’ is the power of the direct signal at the output of the precoder in milliWatts, and
Ptotal_Zi' is the power of the full signal (direct signal + crosstalk pre-compensation signals) at the output of
the precoder in milliWatts; for subcarrier i.

NOTE 3 – With the requirements above, the received signal total power is not measured during reception of sync,
quiet, idle and data symbols in DOI. For SATN_DS the transmitted signal power in dBm, TXpower_dBm_DS, is
calculated by the VCE for the direct signal only, after scaling to remove any change in power caused by the precoder,
and by the transmit filtering.
The SATN_DS shall be updated during showtime, during L0 link state only, on request of the DPU ME in
response to an update request for near-end test parameters (see clause 7.1.9.1 of [ITU-T G.997.2]). The
FTU-R, accordingly, shall send on request the updates of the RXpower_dBm_DS via eoc (see clause
11.2.2.13). The RXpower_dBm_DS shall be calculated during L0 link state only.

The received signal total power RXpower_dBm_DS, shall be represented as a 10-bit unsigned integer p. The
value of RXpower_dBm_DS shall be coded as:
RXpower_dBm_DS = 20 – (p/10) dBm.
This data format supports an RXpower_dBm_DS granularity of 0.1 dB. The set of valid values ranges from
+8 dBm to −80 dBm, corresponding to the set of valid values of p =120 to 1000.
A special value p = 119 indicates a value of RXpower_dBm_DS = 8.0 dBm or higher.

A special value p = 1001 indicates a value of RXpower_dBm_DS = –80.1 dBm or lower.
A special value p = 1023 indicates that the parameter is undetermined.

All other values for p are reserved by ITU-T.
Towards the DPU-MIB, the signal attenuation, SATN_DS, shall be represented as a 10-bit unsigned integer

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