Comtech EF Data DMD50 Installation And Operation Manual page 10

Table of Contents
DMD50 Universal Satellite Modem
3.4 Async Port / ES-ES Communications ....................................................................................... 3-7
3.5 Internal Clock .............................................................................................................................. 3-7
3.6 2 2 B L oopback Features (Terrestrial & IF) ...................................................................................... 3-8
3.7 Clocking Options ....................................................................................................................... 3-11
3.7.1 TX Clock Options ............................................................................................................... 3-11
3.7.1.1 SCTE: Serial Clock Transmit External ........................................................................... 3-12
3.7.1.2 SCT: Serial Clock Transmit ............................................................................................ 3-12
3.7.2 RX Buffer Clock Options ................................................................................................... 3-12
3.7.2.1 RX SAT Clock ................................................................................................................ 3-13
3.7.2.2 SCTE: Serial Clock Transmit External ........................................................................... 3-13
3.7.2.3 SCT: Serial Clock Transmit ............................................................................................ 3-13
3.7.2.4 EXT CLK/EXT BNC: External Clock, J16 .................................................................... 3-13
3.7.2.5 EXT IDI: Insert Data In .................................................................................................. 3-14
3.7.3 EXT REF: External Reference, Top BNC Port, J10 ........................................................... 3-14
3.8 RS530/422/V.35 Interface (Standard) ..................................................................................... 3-14
3.8.1 G.703 Interface (Optional) .................................................................................................. 3-14
3.8.2 HSSI Interface (Optional) ................................................................................................... 3-15
3.8.3 Ethernet Data Interface (Optional) ...................................................................................... 3-15
3.9 Reed-Solomon Codec ................................................................................................................ 3-15
3.9.1 Reed-Solomon Operation .................................................................................................... 3-15
3.9.2 Reed-Solomon Code Rate ................................................................................................... 3-15
3.9.3 Interleaving ......................................................................................................................... 3-16
3.10 Asynchronous Overhead Operation (Framing/Multiplexer Capability) ............................. 3-17
3.11 Standard IBS Mode .................................................................................................................. 3-18
3.12 Asynchronous Multiplexer Mode ........................................................................................... 3-19
3.13 2 9 B E SC Backward Alarms ............................................................................................................. 3-19
3.13.1 To Disable the ESC Backward Alarms ............................................................................... 3-20
3.14 DoubleTalk Carrier-in-Carrier Option .................................................................................. 3-21
3.14.1 What is DoubleTalk Carrier-in-Carrier? ............................................................................. 3-21
3.14.2 Application Requirements ................................................................................................... 3-22
3.14.3 Operational Recommendations ........................................................................................... 3-24
3.14.4 System Functionality and Operational Considerations ....................................................... 3-25
3.14.5 DoubleTalk Carrier-in-Carrier Cancellation Process .......................................................... 3-27
3.14.6 Margin Requirements .......................................................................................................... 3-29
3.14.7 Carrier-in-Carrier Latency .................................................................................................. 3-29
3.14.8 Carrier-in-Carrier and Adaptive Coding and Modulation ................................................... 3-29
3.14.9 Carrier-in-Carrier Link Design ........................................................................................... 3-29
3.14.9.1 Symmetric Data Rate Link .............................................................................................. 3-30
3.14.9.2 Asymmetric Data Rate Link ........................................................................................... 3-33
3.14.9.3 Power Limited Links ....................................................................................................... 3-34
3.14.10 Carrier-in-Carrier Commissioning and Deployment ...................................................... 3-35
3.14.11 Validating Carrier-in-Carrier Performance ..................................................................... 3-36
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Revision 3
MN-DMD50