Chapter 1 Introducing the MQAM
System Overview
The MQAM delivers compressed and encoded, multi-program Moving Picture
Expert Group (MPEG) transport streams of interleaved voice, video, and data in the
RF spectrum to Digital Home Communications Terminals (DHCTs). The MQAM
performs the following functions within the DBDS:
Uses two ASI inputs to allow:
- MPEG stream multiplexing of two MPEG data sources
- Use of the second input as a redundant port
Allows direct input from a variety of MPEG data sources at various rates, such as
video-on-demand (VOD) servers, SONET-to-ASI converters, Grooming BIGs,
and Multiple Decryption Receivers (MDR)
Processes an MPEG transport stream (TS) at various rates
Allows Stream Encryption and Management
Contains four, independent RF Output channels, allowing the MQAM to use
only one unit of rack space for the MQAM hardware and one unit of rack space
for ventilation while replacing the RF output capabilities of four D9476 QAM
Modulators
Features
The MQAM provides many digital broadcast features and innovations for your
system. The following table describes these features and innovations.
Feature
Dual ASI Inputs
Multiplexing
Functionality
2
Function
Supports maximum ASI data rate at both inputs (216 Mbps
each)
Program and Packet Identifier (PID) remapping and filtering
Full routability of MPEG programs. The MQAM can route any
MPEG program from both of its inputs to any combination of
outputs.
Single programs can be sent to any combination of the four RF
outputs simultaneously (multicast).
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