Page 744 - 5G Basics - Core Network Aspects

2 Transport aspects

Table 9-5 – Downstream RMC command (sent by FTU-O only)

Field name Format Description
Upstream logical frame Three bytes Request for upstream logical frame configuration
configuration request parameters (see clause 8.1.1 for the definition of its
implementation). (Note 2)
The format of Upstream logical frame configuration request
is defined in Table 9-7.
Expected transmission time One byte: [000 aaaaa = expected transmission time expressed in symbols
(ETT) aaaaa] for the current logical frame, specified as the symbol
position index of the last data symbol expected to be
transmitted in the logical frame. The actual transmission
time shall be less than or equal to the value communicated
(Note 3).

DTU sync value (NB) Two bytes: The value of NB, for the current logical frame (see definition
byte 0 [s7 ... s0] of NB in clause 9.5) expressed in bytes:
byte 1 [0000 s11... The value is coded as a 12 bits unsigned integer [s11 ... s0]
s8] with s0 the LSB.
The valid range for the DTU sync value is from 00016 to
FEF16.
Current active bit-loading One byte: [bbbb Indication for the active bit-loading table to be used in the
table identifier aaaa] current logical frame, expressed as a value of FCCC
(see clause 13.3.1.1.3).
aaaa = Identifier for the active bit-loading table to be used
over the NOI.
bbbb = Identifier for the active bit-loading table to be used
over the DOI (Note 1). See Table 9-10.

NOTE 1 – If only the NOI is used (i.e., if TTR ds ≥ TBUDGET ds) for a given logical frame, the identifier corresponding to the DOI shall
be set to 0000 by the transmitter and ignored by the receiver.
NOTE 2 – If the FTU-R receives a new upstream logical frame configuration request in the downstream RMC of downstream
logical frame with CNT LF,ds = N + M SF, the FTU-R shall indicate this new configuration in the RMC starting from upstream logical
frame with CNT LF,us = N+1 and apply this new configuration in the logical frame with CNT LF,us = N+1 if MB equals to 0 or with
CNT LF,us = N + 2 if MB equals to 1 (see Figure 10-27).
NOTE 3 – If RMC is the only symbol expected to be transmitted in a logical frame, the value of ETT shall be set to 00000 2.

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