Page 947 - 5G Basics - Core Network Aspects

Transport aspects 2

– the FTU-O and FTU-R exchange capabilities and negotiate relevant parameters of TPS-TC (e.g., DTU
size), PMS-TC (e.g., FEC parameters) and PMD (e.g., bits and gains tables) for showtime;
– for bits and gains setting, the FTU-O and FTU-R estimate the actual SNR in upstream and
downstream directions, respectively.
At the end of this stage, both FTU-O and FTU-R apply the exchanged bits and gains tables and transition to
showtime as described in clause 12.3.5.
Figure 12-12 presents the timing diagram for the stages of the channel analysis and exchange phase. It
gives an overview of the sequence of signals transmitted and the sequence of SOC messages sent by the
FTU-O and FTU-R during the channel analysis and exchange phase. The two inner columns show the
sequences of signals that are transmitted (see clause 12.3.4.3), and the two outer columns identify the
messages sent in the SOC (see clause 12.3.4.2). The shaded areas correspond to periods of time when SOC
is inactive.

Downstream Upstream
Signals Signals
SOC Messages SOC Messages
Channel Discovery phase Channel Discovery phase
O-P-SYNCHRO 5 R-IDLE
O-IDLE
R-IDLE
O-MSG 1 R-MSG 2
CHANNEL ANALYSIS and EXCHANGE phase (FTU-O) O-IDLE O-P-MEDLEY R-P-MEDLEY R-ACK 1 CHANNEL ANALYSIS and EXCHANGE phase (FTU-R)
O-IDLE

O-TPS
R-IDLE

O-PMS
R-IDLE
O-IDLE
R-PMS
O-PMD

R-PMD
O-IDLE R-IDLE
O-ACK
O-IDLE R-IDLE
O-P-SYNCHRO 6
1 superframe
Showtime
Showtime

Figure 12-12 – Timing diagram of the channel analysis and exchange phase

The SOC messages shown in Figure 12-12 shall use the rules of the communication protocol defined in
clause 12.2.2, using RQ mode. Symbol encoding of symbols shall be as defined in clause 10.2.2.2.

The channel analysis and exchange phase, as shown in Figure 12-12, involves the following steps:
1) The FTU-O sends the O-MSG 1 message, which contains the FTU-O's TPS-TC, PMS-TC and PMD
related capabilities and main requirements for downstream transmission.

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