docsPnmCmDsConstDispMeasTable
DOCS-PNM-MIB ·
.1.3.6.1.4.1.4491.2.1.27.1.2.4
Object
table
The downstream constellation display provides received QAM
constellation points for display. Equalized soft decisions (I and Q)
at the slicer input are collected over time, possibly subsampling to
reduce complexity, and made available for analysis. This measurement is
intended for data subcarriers only. Up to 8192 samples are provided for
each query; additional queries can be made to further fill in the plot.
The complex Constellation Display values are expressed as 16 bit two's
complement numbers using s2.13 format. The CM samples are scaled such
that the average power of the QAM constellation is approximately 1, in
order to avoid excessive clipping and quantization noise.
The object controls the CM capturing and reporting of received
soft-decision samples, for a single selected constellation
from the set of profiles it is receiving, within a single OFDM
downstream channel.
This table will have a row for each ifIndex for the modem.
Context
- MIB
- DOCS-PNM-MIB
- OID
.1.3.6.1.4.1.4491.2.1.27.1.2.4- Type
- table
- Status
- current
- Parent
- docsPnmCmObjects
- Siblings
- 9
- Children
- 1
Syntax
No syntax metadata recorded.
Values & Constraints
No enumerated values or constraints recorded.
Related Objects
Sibling Objects
| Object | Type | Syntax | OID |
|---|---|---|---|
| docsPnmCmControlObjects | node | - | .1.3.6.1.4.1.4491.2.1.27.1.2.1 |
| docsPnmCmUsPreEqTable This object provides access to CM upstream pre-equalizer coefficients.
The CM pre-equalizer coefficients and the CMTS upstream adaptive
equalizer coefficient update values, when t… | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.10 |
| docsPnmCmDsOfdmSymCapTable The purpose of downstream symbol capture is to provide partial
functionality of a network analyzer to analyze the response of the
cable plant from the CM's perspective.
… | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.2 |
| docsPnmCmOfdmChanEstCoefTable The purpose of this table is for the CM to report its estimate of the
downstream channel response. The reciprocals of the channel response
coefficients are typically used by the C… | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.3 |
| docsPnmCmDsOfdmRxMerTable This item provides measurements of the receive modulation error ratio
(RxMER) for each subcarrier. Each subcarrier RxMER value consists of one
byte which represents the RxMER valu… | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.5 |
| docsPnmCmDsOfdmMerMarTable The purpose of this item is to provide an estimate of the MER margin
available on the downstream data channel with respect to a candidate
modulation profile. This is similar to th… | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.6 |
| docsPnmCmDsOfdmFecTable The purpose of the table is to provide a series of codword error rate
measurements on a per profle basis over a set period of time.
This table will have a row for each … | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.7 |
| docsPnmCmDsOfdmReqMERObjects | node | - | .1.3.6.1.4.1.4491.2.1.27.1.2.8 |
| docsPnmCmDsHistTable The purpose of the downstream histogram is to provide a measurement of
nonlinear effects in the channel such as amplifier compression and laser
clipping. For example, laser clippi… | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.9 |
Child Objects
| Object | Type | Syntax | OID |
|---|---|---|---|
| docsPnmCmDsConstDispMeasEntry The conceptual row of the docsPnmCmDsConstDispMeasTable. An instance
is dynamically created and exists for an associated ifIndex upon
which the test defined by this table can take… | row | - | .1.3.6.1.4.1.4491.2.1.27.1.2.4.1 |