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1 INTRODUCTION
The Motorola OM 2000 Out-of-band Modulator links the digital headend equipment
with the distribution system by combining the various out-of-band inputs into a
quadrature phase shift key (QPSK)-modulated signal. It converts multiple digital input
streams into an RF output signal for transmission over the cable system.
Figure 1-1 — OM 2000 Out-of-band Modulator
The OM 2000:
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Receives Ethernet User Datagram Protocol (UDP) packets from a controlling
processor
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Multiplexes downstream data from multiple sources
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Provides forward error correction (FEC) encoding of the bitstream, as well as
interleaving and randomization
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Provides downstream QPSK-modulated output within the 71 to 129 MHz range
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Provides industry-standard Ethernet 10Base-T connectivity for operation,
administration, maintenance, and provisioning (OAM&P)
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Performs periodic insertion of internally stored messages
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Controls and provides status/alarm reporting using Simple Network Management
Protocol (SNMP)
