Defining Modulation Profiles - ADC CUDA 3 Administration Manual

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HAPTER ONFIGURING

Defining Modulation Profiles

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ABLE ODEM ERMINATION
Modulation profiles contain the profile properties of the CMTS upstream
data stream channels. The CMTS supports two profiles for the four upstream
channels. Each profile consists of a burst descriptor for the following Interval
Usage Codes:
Request: Interval when a request on bandwidth can be sent by the
modem.
Initial Maintenance: Interval when new modems can start establishing a
connection with CMTS with Initial Ranging Requests.
Station Maintenance: Interval when modems perform periodic ranging
with periodic ranging for adjusting power, timing and frequency.
Short Data: Interval when a modem can send upstream PDU (Protocol
Data Unit), which is less than one maximum burst size.
Long Data: Interval when the modem can send upstream PDU, when
one burst size exceeds one maximum burst size on the short data interval.
For each above-mentioned Usage Code, you must define eleven profile
parameters as described in the following sections.
Caution: Profiles affect the physical layer. Changes to profile properties
affects the performance and function of the CMTS. It is recommended that
an expert-level user perform Modulation Profile configuration.
Guard Time
The Guard Time parameter is the number of symbol-times that must follow
the end of this channel's burst. Note that this parameter is read-only.
S
YSTEMS
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