Page 964 - 5G Basics - Core Network Aspects

2 Transport aspects

(see clause 10.2.2.4.2). The scrambler shall be initialized at the first SOC symbol of O-P-MEDLEY signal with
the seed obtained during the ITU-T G.994.1 handshake and continued until the end of O-P-MEDLEY signal.
The FTU-O shall transmit all SOC messages in RQ mode.
The FTU-O shall start transmission of the O-P-MEDLEY signal right upon completion of transmission of the
O-P-SYNCHRO 5 signal, from symbol with index zero of the following downstream logical frame. From the
start of the first superframe of the O-MEDLEY, the SOC shall transmit O-IDLE for the three subsequent
superframes and then transmit the O-MSG 1 message. After receiving acknowledgement from the FTU-R
(via R-MSG 2 message), the FTU-O sends O-TPS message. After O-TPS message is acknowledged by the
FTU-R (via R-TPS), the FTU-O sends O-PMS message. After O-PMS message is acknowledged by FTU-R (via
R-PMS message), the FTU-O sends O-PMD message.

After the O-PMD message has been acknowledged by the FTU-R (via R-PMD message), the FTU-O
completes the message exchange by sending the O-ACK message and further terminates O-P-MEDLEY
signal after transmitting six superframes of O-IDLE by sending the O-P-SYNCHRO 6 signal. The start time of
O-P-SYNCHRO 6 signal transmission shall be at the symbol with index zero of the first downstream logical
frame of a superframe, but the time between transmission of O-ACK message and transmission of O-P-
SYNCHRO 6 signal shall not exceed nine superframes.

12.3.4.3.2 O-P-SYNCHRO 6
The O-P-SYNCHRO 6 signal provides an exact time marker for transition from the channel analysis and
exchange phase to showtime. The structure of O-P-SYNCHRO 6 signal shall be the same as O-P-SYNCHRO 1
signal, except that the SOC quadrant scrambler shall be in free running mode and the inverted symbols
containing SOC IDLE (see clause 12.2.3 for the equivalent definition when the SOC is in the active state)
shall use normal bit mapping and the IDS shall not be applied. During transmission of the O-P-SYNCHRO 6
signal, the SOC shall be inactive.
The element of the probe sequence carried by the sync symbol of the O-P-SYNCHRO 6 signal shall continue
the probe sequence transmitted during the O-P-MEDLEY signal with no interruption.
12.3.4.3.3 R-P-MEDLEY

During transmission of the R-P-MEDLEY signal the FTU-R receives from the FTU-O and communicates to the
FTU-O 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 to negotiate common
values of these parameters at the FTU-O and FTU-R. The R-P-MEDLEY signal is also used by the FTU-O to
estimate the upstream SNR.
The R-P-MEDLEY signal has the same structure as the R-P-CHANNEL-DISCOVERY 1 signal and shall consist of
upstream sync symbols and initialization symbols. Sync symbols shall be transmitted at each upstream sync
symbol position. SOC symbols shall be transmitted at the first sus symbol positions of each upstream 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) with the number of repetitions p
determined during the channel discovery phase. The SOC symbol repetition rate shall be set to 0
(no repetitions) and no IDS shall be applied. The SOC quadrant scrambler shall be kept in free running
mode. The scrambler shall be initialized at the first SOC symbol of R-MEDLEY with the seed obtained during
the ITU-T G.994.1 handshake and continued until the end of R-P-MEDLEY signal. The FTU-R shall transmit all
SOC messages in RQ mode.
The FTU-R shall start transmission of the R-P-MEDLEY signal after reception of the O-P-SYNCHRO 5 signal,
from the symbol with index 0 of the upstream logical frame that follows the last symbol of O-P-SYNCHRO 5
signal. From the start of the first superframe of the R-P-MEDLEY signal, the SOC shall transmit O-IDLE until
reception of the O-MSG 1 message. The FTU-R shall acknowledge O-MSG 1 message by sending R-MSG 2
message and wait for reception of O-TPS message. The FTU-R shall acknowledge the O-TPS message by

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