Cable Upstream Power-Level - Motorola BSR 64000 Reference Manual

BSR 64000 Command Reference Guide

cable upstream power-level

The BSR CMTS interface controls CM output power levels to meet the desired
CMTS upstream input power level. Input power level adjustments to an upstream port
compensate for CMTS signal degradation between the optical receiver and the
upstream RF port.
The cable upstream power-level command is used to set the upstream input power
level in absolute mode. In absolute mode, the input power level does not change when
the upstream channel width is changed. Defining the input power level in absolute
mode could possibly cause upstream return lasers to clip on a completely populated
upstream channel.
Caution: If the power level is not explicitly set on the upstream interfaces,
they default to 0 dBmV in absolute mode with a 3.2 MHz, 2560 kilosymbols
per second rate. Ensure that the correct power level is set on each upstream
channel.
Table 13-2
power-level range and default power-level range for a specific upstream channel.
Caution: Use caution when increasing the input power level in absolute
mode. The CMs on the HFC network increase their transmit power level by 3
dB for every incremental upstream channel bandwidth change, causing an
increase in the total power on the upstream channel. This may violate the
upstream return laser design parameters
13-70
describes how the upstream channel bandwidth corresponds to the input
Table 13-2 Upstream Input Power Level Range Parameters
Upstream Channel
Bandwidth
200 KHz
400 KHz
800 KHz
1.6 MHz
3.2 MHz
Default Power-level
Range
-1 dBmV
+2 dBmV
+5 dBmV
+8 dBmV
+11 dBmV
Power-level
Range
-16 to +14 dBmV
-13 to +17 dBmV
-10 to +20 dBmV
-7 to +23 dBmV
-4 to +26 dBmV