Page 952 - 5G Basics - Core Network Aspects

2 Transport aspects

Field 16 "Downstream lom defect persistency (LOM-PERSISTENCYds)" contains the value of the control
parameter lom_persistency-ds. The parameter is used in the fast-retrain trigger criteria (see clause 12.1.4.2)
and is defined in clause 12.1.4.3.2. The field has valid values from 2 to 20 (1416) in steps of 1.
Field 17 "Downstream lor defect persistency (LOR-PERSISTENCYds)" contains the value of the control
parameter lor_persistency-ds divided by 100. The parameter is used in the fast-retrain trigger criteria (see
clause 12.1.4.2) and is defined in clause 12.1.4.3.3. The field has valid values from 1 to 20 (1416) in steps
of 1.

Field 18 "Downstream reinit time threshold (REINIT-TIME-THRESHOLDds)" contains the value of the control
parameter reinit_time_threshold-ds. The parameter is used in the conditions for declaring a High_BER
event (see clause 12.1.4.3.4) and is defined in clause 12.1.4.3.4. The field has valid values from 5 to
31 (1F16) in steps of 1.
Field 19 "Downstream low ETR threshold (LOW-ETR-THRESHOLDds)" contains the value of the control
parameter low_ETR_threshold-ds. The parameter is used in the conditions for declaring a High_BER event
(see clause 12.1.4.3.4) and is defined in clause 12.1.4.3.4. The field has non-zero valid values from 1 to 30
(1E16) in steps of 1. The valid value 0 indicates that no High_BER event shall be declared based on ETR being
below the ETR_min_eoc.
Field 20 "Downstream target SNR margin for RMC (TARSNRM-RMCds)" indicates the target SNR margin for
the downstream RMC. For definition of TARSNRM-RMC see clause 13.2.1.3.1. The field shall be formatted
as a 16-bit unsigned integer with LSB weight of 0.1 dB and the valid range between 0 and 31 dB.
Field 21 "Downstream minimum SNR margin for RMC (MINSNRM-RMCds)" indicates the minimum SNR
margin for the downstream RMC. For definition of MINSNRM-RMC see clause 13.2.1.3.1. The field shall be
formatted as a 16-bit unsigned integer with LSB weight of 0.1 dB and the valid range between 0 and 31 dB.

Field 22 "Downstream maximum bit-loading for RMC (MAXBL-RMC)" indicates the maximum allowed
bit-loading for the downstream RMC subcarriers. For definition of MAXBL-RMC see clause 13.2.1.3.1. The
field shall be formatted as an eight-bit unsigned integer with valid range from 2 to 6.

Field 23 contains the "L2 link state control parameter field". This field is a variable length field that contains
multiple fields as represented in Table 12-41.1.

Table 12-41.1 – L2 link state control parameter field in O-MSG1

Field Field name Format

1 L2 link state control parameter field length One byte (Note)
2 Downstream target SNR margin for L2.1 and L2.2 (L2_TARSNRM) Two bytes
3 Downstream maximum SNR margin for L2.1 (L2.1_MAXSNRM) Two bytes
4 Downstream maximum NDR in L2.1 (L2.1_NDR_max) Two bytes
5 Downstream minimum ETR in L2.1 (L2.1_ETR_min) Two bytes
6 Downstream minimum ETR at L2.1 exit (L2.1_Exit_ETR_min) Two bytes
7 Downstream and upstream maximum NDR in L2.2 (L2.2_NDR_max) Two bytes
8 Downstream and upstream minimum ETR in L2.2 (L2.2_ETR_min) Two bytes
9 Downstream rate adaptation downshift SNR margin in L2.1 (L2.1_RA_DSNRMds) Two bytes

10 Downstream rate adaptation upshift SNR margin in L2.1 (L2.1_RA_USNRMds) Two bytes
NOTE – This length field is included to allow correct parsing of O-MSG1. For this version of the Recommendation, the transmitter
shall set the value of this field to 00 16 or 12 16. Receivers need to be deal with larger values and shall ignore the fields that they do
not understand.

942