docsPnmCmUsPreEqTable
DOCS-PNM-MIB ·
.1.3.6.1.4.1.4491.2.1.27.1.2.10
Object
table
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 taken together describe the
linear response of the upstream cable plant for a given CM. During the
ranging process, the CMTS computes adaptive equalizer coefficients based
on upstream probes; these coefficients describe the residual channel
remaining after any pre-equalization. The CMTS sends these equalizer
coefficients to the CM as a set of Transmit Equalization Adjust
coefficients as part of the ranging process.
The CM Pre-Equalizer coefficients are expressed as 16 bit two's
complement numbers using s2.13 format. The power averaged over all
coefficients approximately 1, in order to avoid excessive clipping and
quantization noise. The Pre-Equalizer coefficient update values sent to
the CM by the CMTS in the RNG-RSP are expressed as 16 bit two's
complement numbers using s1.14 format.
The CM provides the capability to report its upstream pre-equalizer
coefficients (full set or summary) upon request. The CM also provides
the capability to also report the most recent set of Transmit
Equalization Adjust coefficients which were applied to produce the
reported set of upstream pre-equalizer coefficients. The CM indicates
the status of the most recent Transmit Equalization Adjust coefficients
sent to it by the CMTS. If the CM was able to apply the coefficients it
sets the status to success(2). If the CM was unable to fully apply the
adjustments (for example, due to excess tilt or ripple in the channel),
and it was necessary for the CM to clip the coefficients, it sets the
status to clipped(3). If the CM modified the coefficients other than by
simply clipping them, it sets the status to other(1). If for
some reason the CM is unable to apply the adjustments at all, it sets
the status to rejected(4).
The 'docsPnmCmUsPreEqFileEnable' object is used to create files. Other
objects are updated as read.
This table will have a row for each ifIndex for the modem.
Context
- MIB
- DOCS-PNM-MIB
- OID
.1.3.6.1.4.1.4491.2.1.27.1.2.10- 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 |
| 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 |
| docsPnmCmDsConstDispMeasTable 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, possib… | table | - | .1.3.6.1.4.1.4491.2.1.27.1.2.4 |
| 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 |
|---|---|---|---|
| docsPnmCmUsPreEqEntry The conceptual row of the docsPnmCmUsPreEqTable. An instance
is dynamically created and exists for an associated ifIndex upon
which the test defined by this table can take place.
… | row | - | .1.3.6.1.4.1.4491.2.1.27.1.2.10.1 |