The CDM-625A-EN Advanced Satellite Modem builds on a legacy of providing the most efficient satellite modems. With support for VersaFEC® Forward Error Correction (FEC), the revolutionary DoubleTalk® Carrier-in-Carrier® bandwidth compression, additional rolloffs and advanced packet processing, the CDM-625A provides significant savings under all conditions. This combination of advanced technologies enables multi-dimensional optimization, allowing satellite communications users to:
CDM-625A Specifications | |
---|---|
Data Rate | 18 kbps to 25 Mbps, in 1 bps steps (modulation, FEC & data interface dependant) |
Symbol Rate | 18 ksps to 12.5 Msps |
Operating Frequency | 50 – 180 MHz (standard) and 950 – 2250 MHz (option) 100 Hz resolution, independent TX and RX operation |
Major Operating Modes (See User Manual For Details) | Open network, per IESS-308 / 309 / 310 / 314 transparent, closed network per IESS-315 LDPC / TPC Codec (option) VersaFEC Codec (option) with ACM or Constant Coding & Modulation (CCM) EDMAC Framed with/without AUPC RS Outer Codec High rate ESC / Enhanced ESC (ESC++) Drop & insert (D&I) /Enhanced D&I++ (option) Quad E1 drop & insert (QDI) (option) DoubleTalk Carrier-in-Carrier (option) |
FEC & Modulation | |
None | Uncoded BPSK/QPSK/OQPSK |
Viterbi: k=7, per IESS-308/309 | Rate 1/2 BPSK/QPSK/OQPSK Rate 3/4 QPSK/OQPSK Rate 7/8 QPSK/OQPSK |
Viterbi with Reed Solomon | Rate 3/4 16-QAM Rate 7/8 16-QAM |
Sequential | See CDM-625A user manual for details |
Reed Solomon | Open network and closed network modes |
TCM (Per IESS-310) | 8PSK/TCM Rate 2/3 |
Integrated LDPC and TPC (2nd Gen) Codec (Optional Plug-in Module) | LDPC Code Rates Rate 1/2 BPSK/QPSK/OQPSK Rate 2/3 QPSK/OQPSK/8PSK/8-QAM Rate 3/4 QPSK/OQPSK/8PSK/8-QAM/16-QAM TPC Code Rates Rate 5/16 BPSK Rate 21/44 BPSK/QPSK/OQPSK Rate 3/4 QPSK/OQPSK/8PSK/8-QAM/16-QAM Rate 7/8 QPSK/OQPSK/8PSK/8-QAM/16-QAM Rate 0.95 QPSK/OQPSK/8PSK/8-QAM |
VersaFEC Codec (Option) | BPSK Rate 0.488 QPSK Rate 0.533, 0.631, 0.706, 0.803 8-QAM Rate 0.576 (ECCM), 0.642, 0.711, 0.780 16-QAM Rate 0.644 (ECCM), 0.731, 0.780, 0.829, 0.853 BPSK 0.493 (ULL) QPSK 0.493, 0.654, 0.734 (ULL) |
VersaFEC-2 Codec (Option) | Long Block: BPSK Rate 0.489 QPSK Rate 0.489, 0.537, 0.586, 0.611, 0.635, 0.660, 0.684, 0.733 8-QARY Rate 0.521, 0.537, 0.562, 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733 16-QARY Rate 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733, 0.757, 0.782 32-ARY Rate 0.660, 0.684, 0.708, 0.733, 0.757, 0.782, 0.801, 0.831, 0.855, 0.879 Short Block: BPSK Rate 0.489 QPSK Rate 0.489, 0.537, 0.586, 0.611, 0.635, 0.660, 0.684, 0.733 8-QARY Rate 0.521, 0.537, 0.562, 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733 16-QARY Rate 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733, 0.757, 0.782 32-ARY Rate 0.660, 0.684, 0.708, 0.733, 0.757, 0.782, 0.801, 0.831, |
Scrambling | IDR Mode, no RS, - per ITU V.35 (Intelsat variant) IBS mode, no RS - per IESS-309, externally frame synchronized Transparent Closed Network mode, no RS or Turbo coding - per ITU V.35 (Intelsat variant) EDMAC mode, no RS coding - externally frame synchronized - proprietary Turbo Product Code/LDPC/VersaFEC modes - externally frame synchronized - proprietary All RS modes - externally frame synchronized per IESS-308/309/310 |
Management | 10/100Base-T Ethernet with SNMP, HTTP and Telnet support, EIA-232, EIA-485 (2- or 4-wire) |
Form C Relays | Hardware fault, RX and TX traffic alarms, open network backward alarms |
External Reference (Input OR Output) | BNC connector Input: 1, 2, 5, or 10 MHz, -6 dBm to +10 dBm, 50 Ω/75 Ω (nominal) Output: 10 MHz, 2.7 V peak-to-peak ± 0.4 V, low impedance output |
Data Interfaces | |
EIA-422/-530 DCE , Up to 14 Mbps | 25-pin D-sub (female) |
V.35 DCE , Up to 14 Mbps | 25-pin D-sub (female) |
LVDS Serial , Up to 25 Mbps | 25-pin D-sub (female) |
HSSI Serial , Up to 25 Mbps | 25-pin D-sub (female) |
G.703 T1, 1.544 Mbps (Balanced 100 Ω) | 9-pin D-sub (female) or BNC (female) |
G.703 T2, 6.312 Mbps (Unbalanced 75 Ω or balanced 110 Ω) | 9-pin D-sub (female) or BNC (female) |
G.703 E1, 2.048 Mbps (Unbalanced 75 Ω or balanced 120 Ω) | 9-pin D-sub (female) or BNC (female) |
G.703 E2, 8.448 Mbps (Unbalanced 75 Ω) | 9-pin D-sub (female) or BNC (female) |
ASI , Up to 25 Mbps | BNC (female) |
Additional 2.048 Mbps E1 Ports for Quad-E1 (Balanced 120 Ω) | 9-pin D-sub (female) |
Overhead Data | 44-pin High-density D-sub (male) |
Modem Alarms | 15-pin D-sub (male) |
4-port 10/100Base-T Managed Ethernet Switch (Optional Packet Processor Available) | 4 x RJ-45 |
Modulator | |
Frequency Stability | ± 0.06 ppm (± 6 x 10-8), 0° to 50°C (32° to 122°F) with internal reference |
Transmit Filtering | Per IESS-308 |
Alpha (Rolloff) | 5%, 10%, 15%, 20%, 25%, 35% |
Harmonics and Spurious | Better than -60 dBc/4 kHz (typically <-65 dBc/4kHz) Measured from 1 to 500 MHz (50-180 MHz band) Measured F0 ± 500 MHz (950-2250 MHz band) |
Transmit On/Off Ratio | -60 dBc minimum |
Output Phase Noise (dB/Hz - Freq. Offset) < 0.480° rms double sided, 100 Hz to 1 MHz (Minimum 16 dB better overall than the Intelsat IESS-308/309 requirements) | -63.0 dB/Hz - 100 Hz -73.0 dB/Hz - 1 kHz -83.0 dB/Hz - 10 kHz -93.0 dB/Hz - 100 kHz |
Fundamental AC line spurious is -42 dBc or lower The sum of all other single sideband spurious, from 0 to 0.75 x symbol rate, is -48 dBc or lower | |
Output Power | 50-180 MHz: 0 to -25 dBm, 0.1 dB steps 950-2250 MHz: 0 to -40 dBm, 0.1 dB steps |
Power Accuracy | 50-180 MHz: ± 0.5 dB over frequency, data rate, modulation type and temperature range of 15 to 35° C ± 0.8 dB over frequency, data rate, modulation type and temperature range of 0 to 50° C 950-2250 MHz: ± 0.7 dB over frequency, data rate, modulation type and temperature range of 15 to 35° C ± 1.0 dB over frequency, data rate, modulation type and temperature range of 0 to 50° C |
Output Impedance & Return Loss | 50-180 MHz: 50 Ω/75 Ω, 16 dB minimum return loss (18 dB typical), BNC connector 950-2250 MHz: 50 Ω, 19 dB minimum return loss (21 dB typical), Type-N connector |
Clocking Options | Internal, ± 0.06 ppm (SCT) External, locking over a ± 100 ppm range (TT) Loop timing (RX satellite clock) – supports asymmetric operation External clock |
External TX Carrier Off | By TTL ‘low’ signal or external contact closure |
BUC Reference (10 MHz) | Via TX IF center conductor, 10.0 MHz ± 0.06 ppm (with internal reference), selectable on/off, 0.0 dBm ± 3 dB |
BUC Power Supply (HW Option) | 24 VDC, 4.17 Amps max., 90 W @ 50° C 48 VDC, 3.125 Amps max., 150 W @ 50° C (180 W @ 30° C) Supplied through TX IF center conductor and selectable on/off via M&C control |
Demodulator | |
Input Power Range, Desired Carrier | 50-180 MHz: -105 + 10 log (symbol rate) to -70 + 10 log (symbol rate) dBm 950-2250 MHz: -130 + 10 log (symbol rate) to -80 + 10 log (symbol rate) dBm |
Max Composite Operating Level | 50-180 MHz: 94 – 10 log (symbol rate, desired carrier) dBc, +10 dBm max., with the additional requirement that within ± 10 MHz of the desired carrier the composite power is ≤ +30 dBc 950-2250 MHz: 102 – 10 log (symbol rate, desired carrier) dBc, +10 dBm max., with the additional requirement that within ± 10 MHz of the desired carrier the composite power is ≤ +30 dBc |
Absolute Maximum | +20 dBm |
Adaptive Equalizer | 5-tap design, selectable on/off |
Acquisition Range | Programmable in 1kHz increments |
Below 64 ksymbols/sec | ± 1 kHz to ± (Rs/2) kHz, where Rs = symbol rate in ksymbols/sec |
Between 64 and 389 ksymbols/sec | ± 1 kHz to ± 32 kHz |
Above 389 ksymbols/sec | ± 1 kHz to ± (0.1 * Rs) kHz, up to a maximum of ± 200 kHz |
Acquisition Time | Highly dependent on data rate, FEC rate, and demodulator acquisition range. E.g. 120 ms average at 64 kbps, R1/2 QPSK, ± 10 kHz acquisition sweep range, 6 dB Eb/No |
Plesiochronous/ Doppler Buffer | Selectable from 64 to 262,144 bits, in 16-bit steps (Additional limitations for G.704 frame boundaries) |
Receive Clock | RX satellite, TX terrestrial, external reference |
Clock Tracking | ± 100 ppm minimum |
LNB Reference (10 MHz) | Via RX IF center conductor, 10.0 MHz ± 0.06 ppm (with internal reference), selectable on/off, -3.0 dBm ± 3 dB |
LNB Voltage | Selectable on/off, 13 VDC, 18 VDC per DiSEq 4.2 and 24 VDC at 500 mA maximum |
Monitor Functions | Eb/N0 estimate, corrected BER, frequency offset, buffer fill state, receive signal level |
DoubleTalk Carrier-in-Carrier | |
Delay Range | 0 to 330 ms |
Power Spectral Density Ratio (Interferer to Desired) | BSPK/QPSK/8PSK/8-QAM: –7 dB to +11 dB 16-QAM: -7 dB to +7 dB |
Maximum Symbol Rate Ratio | 3:1 (TX:RX or RX:TX) |
Eb/No Degradation | 0 dB Power Spectral Density Ratio BPSK/QPSK/OQPSK: 0.3 dB 8-QAM: 0.4 dB 8PSK: 0.5 dB 8-ARY: 0.4 dB 16-QAM: 0.6 dB 16-ARY: 0.6 dB 32-ARY: 0.6 dB +10 dB power spectral density ratio Additional 0.3 dB |
Satellite Restrictions | Satellite in “loop-back” mode (i.e., the transmit station can receive itself) “Non-processing” satellite (i.e., does not demodulate or remodulate the signal) |
Environmental and Physical | |
Temperature | Operating: 0 to 50°C (32 to 122°F) Storage: -25 to 85°C (-13 to 185°F) |
Power Supply | 100 – 240 VAC, +6%/-10%, 50/60 Hz, auto sensing -24 VDC (HW option) -48 VDC (HW option) |
Dimensions (1RU) (height x width x depth) | 1.75” x 19.0” x 17.65” (4.4 x 48 x 44.8 cm) approximate |
Weight | 10.8 lbs (4.9 kg) maximum, with all option modules and 48 VDC BUC power supply installed |
CE Mark | EN 301 489-1 (ERM) EN55022 (Emissions) EN55024 (Immunity) EN 61000‐3‐2 EN 61000‐3‐3 EN60950 (Safety) |
FCC | FCC Part 15, Subpart B |
Comtech EF Data CDM-625A-EN Advanced Satellite Modem Datasheet