Summary Of Specifications; Versafec Acm - Comtech EF Data CDM-570A Installation And Operation Manual

P.10 Summary of Specifications
P.10.1

VersaFEC ACM

System Type
Symbol Rate Range
Interface
Remote SNR Reporting
Max Span of Data Rate
Switch Point (decreasing SNR)
Switch Point Hysteresis
Max Fading Rate
Max ModCod Update Rate
Configurable Parameters
System Latency
Monitored Parameters
List of ModCods
Adaptive Coding and Modulation (ACM) Option
CDM-570A/570AL Satellite Modem with Optional Packet Processor
Adaptive Coding and Modulation, using BPSK, QPSK, 8-QAM , 16-QAM and
VersaFEC short-block LDPC coding – total of 12 ModCods
37-3000 ksps
10/100 Base T Ethernet, with auto-negotiated Congestion Control
Automatically reported from remote modem – built in function at the physical
layer – requires no additional overhead
7:1 over range of adaptation
Corresponds to SNR (Eb/No) that gives BER = 5 x 10
0.3 dB
Approximately 1 dB/second (higher if Target Eb/No margin >1 dB)
One update every two seconds (no restriction on distance between ModCods)
Minimum and Maximum ModCod (ModCod0 through ModCod11)
•
Remote Demod Unlock Action: Maintain current ModCod
•
Target Eb/No margin (0-4.5 dB, 0.5 dB steps)
•
54 ms max. (for a system operating at 100 ksps, and assuming a WAN
buffer of 20 ms, not including satellite path)
Tx and Rx ModCods
•
Local and Remote SNR
•
(-3.0 to +22.0dB, 0.1dB resolution, ±0.5 dB accuracy)
Config and monitor menus displaying data rate, modulation and code rate update
•
dynamically with ModCod
See Appendix B, Table B-3
P–19
-8
Go to minimum ModCod
Revision 5
MN-CDM570A