Page 874 - 5G Basics - Core Network Aspects

2 Transport aspects

satnds, with the value of satnds coded as:

SATN_DS = satnds/10 (dB).
This data format supports a SATN_DS granularity of 0.1 dB and a SATN_DS range from 0.1 dB to 100.0 dB,
corresponding to the set of valid values of satnds = 1 to 1000.
A special value satnds = 0 indicates a value of SATN_DS = 0 dB or lower.

A special value satnds = 1001 indicates a value of SATN_DS = 100.1 dB or higher.
A special value satnds = 1023 indicates that the parameter is undetermined. All other values for satnds are
reserved by ITU-T.

11.4.1.2.7.2 Upstream signal attenuation (SATN_US)
The upstream signal attenuation, SATN_US, shall be computed by the VCE using the following reference
formula:
SATN_US = TXpower_dBm_US – Direct_RXpower_dBm_US.
For upstream, the transmitted signal power in dBm, TXpower_dBm_US, is the ACTATPus (see Note 1 and
clause 11.4.5).
NOTE 1 – The ACTATPus reported by the FTU-R is defined on 100 Ohms termination impedance (see
clause 11.4.1.2.6). Remark that in this case termination impedance is to be interpreted as the network/loop input
impedance. In actual deployments, the network/loop input impedance may deviate from 100 Ohms resistive.

The FTU-O measures the power of the received subcarriers after post-cancellation and then sums over
those subcarriers with gi>0 that are in the MEDLEYus set to estimate the direct received power.

The FTU-O first computes the power of each direct received subcarrier signal by averaging the power of the
direct received signal on subcarrier i of the post-canceller output samples as follows:
1 Navg 2
Direct_Rec eived_subc arrier_pow er_mW_US(i )   G i) (
Navg k
k 1 ,

where Navg is the number of post-canceller output samples that are used to estimate the average power
and Gk(i) is the result of taking the output sample of the post-canceller and removing the impact of the
receive filter and dividing by the magnitude of the post-canceller matrix diagonal element.
The computed powers for each subcarrier are then summed over all subcarriers to determine the direct
received signal power as:
 
Direct_RXp ower_dBm_U S 10 log 10   Direct_Rec eived_subc arrier_pow er_mW_US (i ) 


 i MEDLEYus ,gi 0  
The FTU-O and VCE shall refer Direct_RXpower_dBm_US back to the U-O interface, assuming the receiving
FTU presents a load impedance to the network of 100 Ohms resistive (see Note 2).
NOTE 2 – In actual implementations, the receiving FTU load impedance may deviate from 100 Ohms resistive.
For SATN_US, the FTU-O's internal measurements are used.
The FTU-O shall average the received total power over at least 256 symbols (consecutive or non-
consecutive). The received 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 SATN_US shall be calculated by the FTU-O during showtime, during L0 link state only, and 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 signal attenuation, SATN_US, shall be represented as a 10-bit unsigned integer satnus, with the value of
satnus coded as:
SATN_US = satnus/10 (dB).

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