Motorola BSR 2000 manual Cable upstream power-level

BSR 2000 Command Reference Guide Release 1.0

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-levelcommand 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 11-2describes how the upstream channel bandwidth corresponds to the input power-level range and default power-level range for a specific upstream channel.

Table 11-2 Upstream Input Power Level Range Parameters

Upstream Channel	Default Power-level	Power-level
Bandwidth	Range	Range
200 KHz	-1 dBmV	-16 to +14 dBmV
400 KHz	+2 dBmV	-13 to +17 dBmV
800 KHz	+5 dBmV	-10 to +20 dBmV
1.6 MHz	+8 dBmV	-7 to +23 dBmV
3.2 MHz	+11 dBmV	-4 to +26 dBmV

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

11-94 MGBI 526363-001-00 Rev. B