Configuring A Downstream Channel; Initial Downstream Configuration Tasks - Motorola BSR 2000 Configuration And Management Manual

Release 1.0

Configuring a Downstream Channel

A downstream channel is configured to control the data flow from the cable interface
to the user CM. This section is divided into two parts. The downstream parameters
that must be configured for the minimal operation of the downstream port are
discussed in the
parameters that are configured to manage the downstream channel operation are
discussed in the
Table 6-6
Parameter
Frequency
Range
Insertion
Interval
Interleave Depth Depth to provide protection from
Modulation Rate Data traffic speed
MPEG Framing
Format
Power Level
SYNC Interval

Initial Downstream Configuration Tasks

Use the tasks in this section to perform the following basic downstream configuration
tasks:
526360-001-00 Rev. B
Initial Downstream Configuration Tasks
Managing the Downstream Channel
contains the downstream parameters.
Table 6-6 Downstream Parameters
Identification
Radio frequency carrier center
frequency
Time available for CM initial
channel request
noise
Annex A (European) standard
Annex B (North American)
standard
Downstream transmit power level
Interval between SYNC message
transmissions
Configuring the Downstream Frequency and Modulation Rate
Default
555,000,000 Hz 93,000,000 to
2,000
milliseconds
32
256 QAM
B
55 dBmV
200
MGBI
Configuring the CMTS
section. The downstream
section.
Value
855,000,000 Hz
100 to 2,000
milliseconds
8, 12, 16, 32,
64, 128,
64 QAM (6 bits)
or 256 QAM (8
bits) per symbol
A or B
45 to 65
decibels per
millivolt (dBmV)
1 to 200
milliseconds
6-45