Cisco Cisco Digital Service Access Node (DSAN) 8211 Troubleshooting Guide
Chapter 1 Introduction
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and cutoff frequency).
All services must have unique source identifiers.
The input carrier should be between 88 MHz and 1002 MHz (91 to 999 MHz
channel center frequencies).
channel center frequencies).
The wideband tuners should cover the input carrier channel frequencies.
The input carrier modulation mode should be QAM 64 or QAM 256.
RF Channel Plan
RF cables 6 through 10 (counting left to right) transfer channels from the digital lid
assembly to the RF module in predefined frequency bands, as follows.
assembly to the RF module in predefined frequency bands, as follows.
RF cable 6 carries EIA channels 63-78 on 456 to 552 MHz.
RF cable 7 carries EIA channels 31-46 on 264 to 360 MHz.
RF cable 8 carries EIA channels 47-62 on 360 to 456 MHz.
RF cable 9 carries EIA channels 22, 7-13, and 23-30 on 168 to 264 MHz.
RF cable 10 carries EIA channels 2-6, 95-99, and 14-21 on 52 to 168 MHz.
This staggered allocation is designed to increase the physical distance between
cables carrying adjacent frequencies, thereby reducing mutual interference.
cables carrying adjacent frequencies, thereby reducing mutual interference.
Note: EIA channels are not contiguous. See Technical Information (on page 75) for a
complete list of the output channel video carrier frequencies. It is important to note
this information before making any channel measurements.
complete list of the output channel video carrier frequencies. It is important to note
this information before making any channel measurements.
Reverse Path Operation
The DSAN provides a buffered signal path from the Mixed Services output port to
the Input port to support reverse communication. A small amount of gain and
response tailoring is applied to make up for passive losses through the DSAN so that
its insertion into the reverse path is transparent. No additional balancing of the
reverse path is needed or provided.
the Input port to support reverse communication. A small amount of gain and
response tailoring is applied to make up for passive losses through the DSAN so that
its insertion into the reverse path is transparent. No additional balancing of the
reverse path is needed or provided.
Diplex filters at the Input and Mixed Services output ports allow signals above 54
MHz to pass in the forward or downstream direction, while allowing signals in the
range of 5 to 42 MHz to pass in the reverse or upstream direction.
MHz to pass in the forward or downstream direction, while allowing signals in the
range of 5 to 42 MHz to pass in the reverse or upstream direction.
Additionally, a splitter in the reverse signal path provides an input port for reverse
DOCSIS data.
DOCSIS data.