Cisco Headend System Release 2.7 User Guide
The Reporting Option
4031374 Rev B
129
Understanding the DHCT Transmit Level Saturation Report
There are two parts to the DHCT Transmit Level Saturation Report:
A graphical representation of the distribution of the various transmission levels
of DHCTs assigned to each QPSK modulator on the system
Note: Read Graphical Distribution of DHCT Transmission Levels (on page 129)
for help in interpreting the graphical representation.
of DHCTs assigned to each QPSK modulator on the system
Note: Read Graphical Distribution of DHCT Transmission Levels (on page 129)
for help in interpreting the graphical representation.
A numerical analysis of the graphical representation of the various transmission
levels of DHCTs assigned to each QPSK modulator on the system
Note: Read Transmit Level Analysis (on page 130) for help in interpreting the
graphical representation.
levels of DHCTs assigned to each QPSK modulator on the system
Note: Read Transmit Level Analysis (on page 130) for help in interpreting the
graphical representation.
Graphical Distribution of DHCT Transmit Levels
The first part of the DHCT Transmit Level Saturation Report contains a graph that
shows the distribution of the various transmission levels of DHCTs assigned to a
specific QPSK modulator. In the following example, the modulator is QPSKMOD1.
The horizontal axis of the graph plots units of dBmV; the vertical axis (not marked
on the report) plots the relative number of DHCTs transmitting at each dBmV level.
shows the distribution of the various transmission levels of DHCTs assigned to a
specific QPSK modulator. In the following example, the modulator is QPSKMOD1.
The horizontal axis of the graph plots units of dBmV; the vertical axis (not marked
on the report) plots the relative number of DHCTs transmitting at each dBmV level.
Our engineers have determined that DHCTs communicate best with QPSK
modulators and demodulators when the DHCT transmits at a level between 25 and
55 dBmV. Notice the bell curve depicted in the illustration (and highlighted in bold
for easy recognition). The peak of the bell curve centers around 40 dBmV, the
modulators and demodulators when the DHCT transmits at a level between 25 and
55 dBmV. Notice the bell curve depicted in the illustration (and highlighted in bold
for easy recognition). The peak of the bell curve centers around 40 dBmV, the