The Motorola out-of-band multiplexer/ modulator, OM-1000, provides an out-of-band data stream to the digital settop terminals. It is primarily used as a signaling channel but can also provide for transmission of program guide information, code downloads, InfraRed codes, as well as application information. It is also utilized as the downstream path in an interactive system. The input to the Motorola OM-1000 can be configured with a mix of both Ethernet and serial inputs. A Quadrature Phase Shift Key Modulator (QPSK) modulates the data on a 1.5 MHz wide carrier. The Motorola OM-1000 is agile across the 71 – 129 MHz band. The transmitted data packets are composed of data that can be multiplexed either in the Motorola OM-1000 or externally. The Motorola OM-1000 uses null packets as necessary to perform rate aggregation between its inputs and the 2.048 Mbps output. Data integrity is protected by Forward Error Correction encoding and interleaving.
Highlights Includes:
• Transmits MPEG-2 data streams to cable terminals individually or on a broadcast basis
• Data streams consist of authorization information, electronic program guide information, code downloads and interactive traffic
• QPSK modulates data stream in a 1.5 MHz carrier to both IF and RF output ports
• Implements FEC code for cable transmission
• Generates and sends emergency alert packets to cable terminals
• Multiple data accepting ports including RS232, RS530, and Ethernet
• Frequency agile RF output with variable power control
• Industry standard 10 Base-T Ethernet connectivity for status monitoring and network element control
• Supports broadcast messaging
• Supports interactive applications
RF Output
Modulation: DQPSK
Carrier Symbol Rate: 1.024 Mbaud
Carrier Suppression: -30 dB (typical)
Center Frequency: 71 to 129 MHz carrier center frequency
Step Size: 50 kHz
Level: 30 to 50 dBmV
Level Steps: 1 dB (maximum)
Spurious Within
± 1.25 MHz: -40 dBc in 30 kHz BW in CW test mode
Beyond ± 1.25 MHz: -45 dBc in 300 kHz BW
IF Output
Center Frequency: 44 MHz ± 0.005% fixed carrier frequency
Level: 26 dBmV nominal (factory set)
Performance
RF Output Level Stability
vs.Temperature: ± 2dB
Accurancy of RF center: ± 0.01%
Transmit Spectral Density: ± 0.005% (accurancy of IF center frequency)
General Instrument ...
