Juniper Networks G10 CMTS manual Noise Measurement Methodology, Average Upstream Noise Measurement

Noise Measurement Methodology

Noise Measurement Methodology

This section describes the methodology for conducting average and peak upstream noise measurements. The procedures establish a consistent methodology for obtaining the requested information during the characterization of the installation site. We recommend you use the HP 8591C spectrum analyzer for taking these measurements.

Average Upstream Noise Measurement

This section defines a procedure for taking the average upstream noise measurements required as part of the RF plant and HFC environment characterization. We recommend that you take a sample of 10 percent of the nodes terminated at the installation site. Table 33 provides the appropriate setup configuration settings for the HP 8591C spectrum analyzer.

Table 33: Average Noise Spectrum Analyzer Settings

Setting	Value
Start frequency	2 MHz
Stop frequency	45 MHz
Resolution bandwidth	100 kHz
Video bandwidth	30 kHz
Scale	5 dB/div
Internal amplifier	On
Attenuator	0 dB
Reference level offset	-28 dB
Reference level	-5 dBmV
Number of averages	100

You might need to adjust the reference level for your particular test environment.

1.Connect the spectrum analyzer to the selected upstream signal at the upstream splitter or at the CMTS upstream port.

2.Configure the spectrum analyzer using the values defined in Table 33.

3.Start the measurement.

After completing the measurement, the analyzer display should resemble Figure 23 on page 84.

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Prepare the Site 83