Page 977 - 5G Basics - Core Network Aspects

Transport aspects 2

FTU may keep repeating the ''Update RMC parameters'' command until the sync frame of the
superframe with the superframe count on which the new RMC parameters are expected to take
effect.
• Upon reception of the "Update RMC parameters" command, the responding FTU shall respond via
both the eoc (see Table 11-19) and the RMC (see Table 9-16), and perform the required parameter
modifications starting from the RMC symbol of the sync frame of the superframe with the
superframe count indicated in the "Update RMC parameters" command.
– The responding FTU shall include the response over RMC (RPA-R command) into all
transmitted RMC frames until the RMC frame transmitted in the sync frame of the superframe
in which the update of RMC parameter occurs.
– The responding FTU shall respond to each received ''Update RMC parameters'' command, as
defined in clause 11.2.2.5.

• The initiating FTU shall modify its RMC parameters starting from the RMC symbol of the sync
frame of the superframe with the superframe count indicated in the "Update RMC parameters"
command. The initiating FTU shall modify the parameters even in case it gets no
acknowledgement over the eoc or over the RMC (including if it detects that RMC is dysfunctional).
However, the initiating FTU shall abort the procedure if it receives a reject OLR request type 4 on
the "Update RMC parameters" command via the eoc or if it receives a RPA-R command with a
reject indication via the RMC, i.e., the initiating FTU shall refrain from the requested changes in the
RMC and perform another type of OLR to fix the transmission channel first.
NOTE – If the eoc, or the RMC, or both are unreliable, the initiating FTU cannot get confirmation whether the RPA
request arrived or not. To improve robustness, the initiating FTU may continuously repeat the RPA request message,
until acknowledgement via eoc or RMC arrives.

If a persistent lor defect on the upstream or downstream RMC (see clause 12.1.4.3.3) or a high BER event
reinit_time_threshold occurs (see clause 12.1.4.3.4), the line shall go to a controlled restart as defined in
clause 12.1.4.

13.2.1.3.1 Parameters controlling the RPA procedures
The list of DPU-MIB parameters controlling RPA procedures is presented in Table 13-5.

The parameter values can be different for the upstream and downstream.
• FTU-O (upstream): Configured through the DPU-MIB.
• FTU-R (downstream): Configured through the DPU-MIB and communicated to the FTU-R
during initialization (in O-MSG 1 message).

Table 13-5 – Parameters controlling the RPA procedures

Parameter Definition
TARSNRM-RMC The target SNR margin of the RMC is the minimum SNRM-RMC value that the FTU receiver
shall achieve to successfully complete initialization.
The valid values for TARSNRM-RMCus and TARSNRM-RMCds are values between 0 and 31.0
dB in steps of 0.1 dB.
MINSNRM-RMC The minimum SNR margin of the RMC that is used to trigger a RPA procedure (see clause
13.2.1.3).
The valid values for MINSNRM-RMCus and MINSNRM-RMCds are values between 0 and 31.0
dB in steps of 0.1 dB.
MAXBL-RMC The maximum bit loading allowed for RMC subcarriers.
The valid values for MAXBL-RMCus and MAXBL-RMCds are integer values from 2 to 6.

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