Release 1.0
Configuring the CMTS
526360-001-00 Rev. B
MGBI
6-45
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
Initial Downstream Configuration Tasks
section. The downstream
parameters that are configured to manage the downstream channel operation are
discussed in the
Managing the Downstream Channel
section.
contains the downstream parameters.
Initial Downstream Configuration Tasks
Use the tasks in this section to perform the following basic downstream configuration
tasks:
■
Configuring the Downstream Frequency and Modulation Rate
Table 6-6 Downstream Parameters
Parameter
Identification
Default
Value
Frequency
Range
Radio frequency carrier center
frequency
555,000,000 Hz
93,000,000 to
855,000,000 Hz
Insertion
Interval
Time available for CM initial
channel request
2,000
milliseconds
100 to 2,000
milliseconds
Interleave Depth Depth to provide protection from
noise
32
8, 12, 16, 32,
64, 128,
Modulation Rate Data traffic speed
256 QAM
64 QAM (6 bits)
or 256 QAM (8
bits) per symbol
MPEG Framing
Format
Annex A (European) standard
Annex B (North American)
standard
B
A or B
Power Level
Downstream transmit power level
55 dBmV
45 to 65
decibels per
millivolt (dBmV)
SYNC Interval
Interval between SYNC message
transmissions
200
1 to 200
milliseconds
Содержание BSR 2000
Страница 1: ...BSR 2000 Configuration and Management Guide 526360 001 00 Rev B Release 1 0 MGBI ...
Страница 6: ... Motorola Motorola Motorola Motorola Motorola Motorola Motorola Motorola Motorola ...
Страница 50: ......
Страница 130: ......
Страница 164: ......
Страница 458: ......
Страница 490: ......
Страница 580: ......
Страница 632: ......
Страница 648: ......
Страница 649: ......
Страница 650: ...526360 001 00 Rev B 7 06 MGBI Visit our website at www motorola com ...