Page 963 - 5G Basics - Core Network Aspects

Transport aspects 2

Other values are reserved by the ITU-T.

If an initialization success/failure code 0016, 8116 or 8216 is set:
– all values in fields 3, 4, 5 and 6 shall be set to 0; and
– the FTU-R shall return to L3 link state instead of L0 link state at the completion of the initialization
procedures.
Field 9 "Downstream FRA sub-bands" contains the start and stop frequencies of the FRA sub-bands (see
clause 13.3.1.1) for the downstream direction. It shall be formatted as a band descriptor (see Table 12-21)
and shall specify up to eight contiguous sub-bands.
12.3.4.2.9 O-ACK

The O-ACK is a one-byte SOC message that acknowledges correct reception of the R-PMD message. The
format shall be as defined in Table 12-54.

Table 12-54 – O-ACK message

Field Field name Format

1 Message descriptor Message code
Field 1 "Message descriptor" is a unique one-byte code (0B16) that identifies the message. See Table 12-7
for a complete list of codes.

12.3.4.3 Signals transmitted during the channel analysis and exchange phase
All signals transmitted during the channel analysis and exchange phase shall use only subcarriers from the
MEDLEYds set in the downstream direction and subcarriers from the MEDLEYus set in the upstream
direction, as determined during PARAMETER UPDATE stage of the channel discovery phase.

The downstream transmit PSD shall be MREFPSDds, and the upstream transmit PSD shall be MREFPSDus
that were established at the end of the channel discovery phase. The MREFPSDds and MREFPSDus shall be
applied starting from the symbol with index 0 of the first downstream logical frame and the first upstream
logical frame, respectively, of the first superframe of the channel analysis and exchange phase. The values
of CE, us and ds shall be those determined at the end of the ITU-T G.994.1 handshake phase and channel
discovery phase.

12.3.4.3.1 O-P-MEDLEY
During transmission of the O-P-MEDLEY signal the FTU-O communicates to the FTU-R and receives from the
FTU-R using SOC messages specified in clause 12.2.4.2 carrying the relevant parameters, including generic
parameters and parameters of the TPS-TC, PMS-TC and PMD in the aim to set or negotiate common values
of these parameters at the FTU-O and FTU-R. The O-P-MEDLEY is also used by the FTU-R to estimate the
downstream SNR. The SNR may be estimated over the first Sds-snr symbol positions in the downstream
logical frame.
The O-P-MEDLEY signal has the same structure as the O-P-CHANNEL-DISCOVERY 1 signal and shall consist of
the downstream sync symbols and the initialization symbols. Sync symbols shall be transmitted at each
downstream sync symbol position. SOC symbols shall be transmitted at the first sds symbol positions of each
downstream logical frame; all other initialization symbols shall be quiet. The sync symbols shall be
generated and modulated by probe sequences as described in clause 10.2.2.1. The SOC shall be in its active
state.
The probe sequence modulating sync symbols shall be continued from the last stage of the channel
discovery phase with no interruption.
SOC symbols shall use normal bit mapping (see clause 10.2.2.2.1). The SOC tone repetition rate pds shall be
as determined during the channel discovery phase. The SOC symbol repetition rate shall be set to zero
(no repetitions) and no IDS shall be applied. The SOC quadrant scrambler shall be kept in free running mode

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