Page 970 - 5G Basics - Core Network Aspects

2 Transport aspects

combination of the above (depending upon the OLR type), or an eoc response deferring or rejecting the
reconfiguration. If the initiator receives an eoc response to defer or reject the reconfiguration, it shall
abandon the last requested OLR command. A new OLR command may be initiated immediately, with the
exception of reason code "wait", as defined in Table 11-20, for which initiation of a new eoc-based OLR
procedure shall be deferred for at least 1 second.
Upon reception of a receiver initiated OLR command, the responder shall send either an OLR response to
defer or to reject the reconfiguration, or an indication when the reconfiguration shall take effect (see
clause 13.2.1.1.5 for details and timing for SRA and clause 13.2.1.3.3 for RPA). After sending the response,
the responder shall reconfigure the affected PMD, PMS-TC and TPS-TC functions. The responder may defer
or reject the OLR request; in this case it shall supply a reason code from those specified in Table 11-20.

An FTU receiver shall initiate an SRA when the conditions in clause 13.2.1.1.3 or clause 13.2.1.1.4 are
satisfied.

An FTU receiver shall initiate bit swapping when the conditions in clause 13.2.1.2.2 are satisfied.
An FTU receiver shall initiate a RPA when the conditions in clause 13.2.1.3 are satisfied.

An FTU receiver shall only send OLR request commands that meet all of following constraints:
– Impulse noise protection
• at least against a combined threat of worst-case REIN impulses as described by the
retransmission control parameters INP_min_rein and iat_rein_flag and of worst-case SHINE
impulses as described by the retransmission control parameter INP_min_shine, and
• within the latency bounds defined by the control parameter delay_max

• within the minimum RFEC/NFEC ratio rnratio_min
– Net Data Rate NDR ≤ NDR_max

13.2.1.1 SRA procedures
13.2.1.1.1 Parameters controlled by the SRA procedures

The SRA function concerning the adjustment of PMD parameters is accomplished by a coordinated change
to the bits and gain values on the number of subcarriers in the baseline table.

13.2.1.1.1.1 Parameters controlled by autonomous SRA in downstream
The parameters are described in Table 13-2.

Table 13-2 – PMD parameters in autonomous SRA request in downstream

Parameter Definition

d_SRA Delta gain change in the FTU-O transmitter requested by the FTU-R.
This parameter is a frequency independent real scalar.
Valid values are 0.5 ≤ d_SRA ≤ 1 (see clause 11.2.2.5).
bi The actual number of bits per subcarrier requested by the FTU-R.
Valid values are all integers in the [0:FTU-O maximum bit loading] range, and with bi ≤ the bi
values requested in the last TIGA message. "FTU-O maximum bit loading" is a capability indicated
by the FTU-O during initialization in the O-MSG 1 message.

Autonomous SRA in downstream without change in d_SRA may be implemented using OLR request type 1
or 2. Autonomous SRA in downstream with change in d_SRA shall be implemented using OLR request
type 1.

To implement the SRA, the FTU-R shall multiply its current settings of the gain stage in the receiver, for any
subcarrier with gi >0, by the value:

1/d_SRA

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