Figure D-10. Link With Fading At Site a | Mocomtech CDM-QX specification

CDM-Qx Satellite Modem	Revision 5
CnCPerformance Characterization	MN/CDMQx.IOM

Notice from the table, the CnC change is proportional to the uplink fade. The CnC ratio decreases by the amount of the uplink fade at the near end while the CnC ratio increases by the amount of uplink fade at the distant end. Also, the CnC ratio at opposite ends of the link has the same magnitude but opposite sine.

Uplink Fade

-6 dB

Downlink Fade	-6 dB
-4 dB
Rain
Fade	0 dB
	0 dB

Site A

Site B

Figure D-10. Link With Fading At Site A

As shown, the interfering carrier at Site A is attenuated twice passing through both the uplink and returning on the downlink back to Site A. Since the carrier transmitted and then received at Site A is the interfering carrier this extra attenuation is much less of an issue because it makes the CnC ratio more negative (less degradation). In a practical link the interfering carrier might drop into the noise leaving the demodulator to recover the desired carrier nearly absent the undesired interferer.

At Site B, the desired carrier from Site A is received and attenuated thereby increasing the CnC ratio (more degradation). In links similar to these, the unfaded end of the link has the highest CnC ratio.

In links without rain fade, the CnC ratio is constant and only the asymmetry of link due to satellite footprint, different antenna sizes, different symbol rates, or modulation and code rates alter the ratio.

D–10

Image 252

Mocomtech CDM-QX operation manual Figure D-10. Link With Fading At Site a

Contents

CDM-Qx RevisionPage Errata a Acquisition rangePage Errata B Page Errata C Rx Rs n/k ENT IESS-310 network 219/201Page Errata D Tx Rs n/k ENT IESS-310 network 219/201Page Part Number MN/CDMQx.IOM Revision January 20,2007 Customer Support Table of Contents Chapter Functional Description External Connections Evolution of TPC in Comtech Products Comparison of all TPC Modes 11-1 Management Information Base MIB Files About this Manual Electrical Safety International Symbols CE Mark Warranty Policy CDM-Qx Satellite Modem Revision Preface MN/CDMQx.IOM Xii Introduction CDM-Qx/QxL Features DoubleTalk Carrier-in-Carrier Software Flash UpgradingVerification Remote Control Data InterfacesTurbo Product Coding Assembly Description Major Assemblies Fast Options and Hardware Options Fast Fast Accessible Options Fast System TheoryImplementation Hardware Options Supporting Hardware and Software Band Compatibility CDM-Qx Satellite Modem Revision Introduction MN/CDMQx.IOM Installation Unpacking Optional Rear-Mounting Installation Bracket Mounting Installation of the Optional Mounting Brackets Configuration Select Internal if LoopConnect External Cables Observe the following Functional Description Page Modem Block Diagram Page Connections Front Panel LED Rear Panel Rear PanelPage Modem Rear Panel Connectors Name Ref. Desig Connector Type FunctionBNC IEC RF Output 75 or 50Ω 2 M&C 10/100BaseT Connector 3 485/232 ConnectorRemote Control Interface Connector Pin Assignments Use for 2-wire RS-485 operation Alarms Connector Alarm Interface Connector Pin AssignmentsPin # Signal Function Name Balanced G.703 Connector Tx/Rx Connector Unbalanced G.703 Tx/Rx ConnectorsBalanced G.703 Interface Connector Pin Assignments Pin # Signal Function Name Direction 7 RS-530 Data Interface Connector Pin # Generic Signal Description Direction RS-422 RSLvds RS-232 Circuit # Quad E1 Data Interface Connectors Xx6. Quad E1 Data Interface J1 Connector Pin Assignments RX and TX if Connectors AC Power ConnectorDC Power Connector AC Power Specifications Ground Connector This page is intentionally left blank Operation Front Panel LED Indicators LEDColor Condition Diamond Keypad Presently used on all Units ENTCLR Left-Hand Display Area ModemsRight Hand Display Area TXF Redundancy MD MD Accessing the Display Area Spectrum AnalyzerRight-Hand Display Area RXS Principle Menu Tree Main Menu Config Monitor Test Info Save/Load Util ODU Opening ScreenComtech EF Data CDM-Qx Firmware Version ODU Config Config Remote Tx Rx Group Frame Interface Ref Mask ODU Config„Remote Remote Control Config„Remote„SerialConfig„Remote„Serial„Interface Config„Remote„Serial„Interface„RS485 RS-485 Bus Address Config„Remote„Serial„BaudrateConfig„Remote„Ethernet Config„Remote„Ethernet„Gateway Config„Remote„Ethernet„AddressConfig„Remote„Ethernet„MAC Config„Remote„Ethernet„SNMP Config„Remote„Ethernet„SNMP„Communities Config„Remote„Ethernet„SNMP„TrapsSnmp Trap Community , ENT comtech Trap Version ENT SNMPv1 SNMPv2Trap IP Addr#1 ENT Trap IP Addr#2 ENT Config„Tx Transmit Tx FEC Mod Code Data Freq On/Off Pwr Scram Clk Inv Txα Config„Tx„FEC TX FEC Type Config„Tx„Mod Modulation SchemeTx FEC Vit Vit+RS TCM+RS TPC Config„Tx„Code TX Code Rate Config„Tx„Data TX Data RateTx Code Rate 5/16 21/44 1/2 3/4 17/18 Tx Data Rate 05000.000kbps Sym02500.000ksps Config„Tx„Freq TX if Frequency Tx if Freq 1156.3456 MHz Config„Tx„On/Off Transmit ON/OFF Control Tx if Freq 1156.3456 MHz RF=14156.3456 ENTTx Output State On Off RxTxInhibit Common , ENT Tx Common Output State Off On Config„Tx„Pwr Transmit Power Level Mode Config„Tx„Pwr„Manual Manual ModeConfig„Tx„Pwr„AUPC Aupc Mode Config„Tx„Pwr„AUPC Target Eb/No Config„Tx„Pwr„AUPC MAX RangeConfig„Tx„Pwr„AUPC Alarm Config„Tx„Pwr„AUPC DEMOD-UNLOCK Config„Tx„Pwr„Combined Combined Transmit Power Config„Tx„Scram ScramblerConfig„Tx„Clk TX Clocking Mode Config„Tx„Inv TX Inversion Functions Tx Inversion functions Spectrum Data Clock ,ENTTx Spectral Inversion Normal Inverted Tx Data Sense Config„Tx„Txα TX Roll-Off α factor Config„Rx ReceiveTx Roll-off 20% 35% ENT RxFEC Demod Code Data Freq Acq Descram Buf Inv Misc CnC Config„Rx„FEC RX FEC Type Rx FEC Vit Vit+RSTCM+RS Case Rules Comment Config„Rx„Demod Demodulation Scheme Config„Rx„Code RX Code RateDemodulation Bpsk Qpsk 8-PSK 16-QAM Rx Code Rate 5/16 21/44 1/2 3/4 7/8 17/18 Config„Rx„Data RX Data Rate Rx Data Rate 05000.000kbps Sym02500.000ksps Config„Rx„Freq RX Frequency Config„Rx„Acq Demod Acquisition RangeRx if Freq1156.3456 MHz RF=12156.3456 ENT Demod Acquisition Range Config„Rx„Descram Descrambler Config„Rx„Buf RX Buffer Clock SourceENT Config„Rx„Inv RX Inversion Functions Config„Rx„Misc Rx Miscellaneous Config„Rx„Misc„EbNo Eb/No Alarm Config„Rx„Misc„Rxα RX Roll-Off α factorConfig„Rx„CnC CARRIER-IN-CARRIER→ Config„Rx„CnC„Mode CnC→ Mode of Operation Config„Rx„CnC„FrqOffs CnC Frequency OffsetPlease Check TX Power Level Please Wait Config„Rx„CnC„SrchDelay CnC Search Delay Config„Rx„CnC„ReAcq CnC RE-ACQUISITION TimeConfig„Group Grouping MOD/DEMOD Cards Config„Group„Modem Config„Group„Redundancy Config„Group„Redundancy„ConfigConfig„Group„Redundancy„Config „11 Config„Group„Redundancy„Config „12 Config„Group„Redundancy„Mode Config„Group„Redundancy„Mode„ManualConfig„Frame Framing Mode Config„Frame„Unframed Unframed Edmac Mode Framing mix AUPC-OnlyAUPC+EDMAC Master Slave Config„Frame„D&I++ D&I++ Distant-end Base Address0240 Address This Slave Unit ENT Config„Interface Data Interface Interface RS422 V.35 RS232Hssi ASI G.703 QDI None RTS/CTS operation , ENT Loop,RTS Controls Tx Out HDB3 AMI T1 Line Length Feet 703 E1 Line Code HDB3 AMI , ENT HDB3 AMI Config„Ref Reference Oscillator Config„Mask MaskAlarm Mask Transmit Receive Reference BUC LNB ,ENT Frequency Reference Internal MHz ENT Tx Alarm Mask Tx-FIFO BPV Tx-AIS ENT Tx-FIFO Alarm ENT Active MaskedRx Alarm Mask AGC Eb/No Rx-AIS Buffer AGC Alarm Reference Alarm BUC AlarmLNB Alarm Config„ODU Outdoor Unit for L-Band Unit Only Config„ODU„BUC Block Upconverter BUCODU BUC LNB Config„ODU„BUC„M&C-FSK M&C FSK Config„ODU„BUC„M&C-FSK„Address FSK CommsConfig„ODU„BUC„M&C-FSK„Address FSK Address BUC M&C Config„ODU„BUC„M&C-FSK„Tx-On/Off FSK TX-ON/OFF Config„ODU„BUC„DC-Pwr BUC DC PowerConfig„ODU„BUC„10MHz BUC 10MHz Config„ODU„BUC„Alarm BUC Alarm Config„ODU„BUC„Delay BUC Delay BUC Current Alarm Upper Limit1200mABUC Current Alarm Lower Limit1200mA Power-On Delay Config„ODU„BUC„LO BUC LO Config„ODU„BUC„Mix BUC MIX Config„ODU„LNB LNB Config„ODU„LNB„Voltage LNB VoltageLNB DC Config„ODU„LNB„Power-On/Off LNB POWER- ON/OFF Config„ODU„LNB„10MHz LNB 10MHzConfig„ODU„LNB„Alarm LNB Alarm Config„ODU„LNB„LO LO Config„ODU„LNB„Mix MIXLNB Current Alarm Lower Limit 050mA ENT LNB Frequency Mix Monitor„Alarms Alarms Monitor„Alarms„Unit Unit Alarms Monitor„Alarms„Receive Receive Alarms Monitor„Alarms„Transmit Transmit AlarmsMonitor„Alarms„ODU Outdoor Unit Alarms Monitor„Rx-Params RECEIVE-PARAMETERS Monitor„Event-Log EVENT-LOG or Stored Events Log 023 30/11/02 Fault Demod Lock 3 ,ENT Monitor„Event-Log„View View Stored EventsLog 024 30/11/97 Clear Demod Lock 3 ,ENT Link Statistics View Clear-All Config ENT Monitor„Stats Link Statistics for grouped as modem onlyMonitor„Stats„View View Link Statistics Monitor„Stats„Config Configure Stats Stats Logging Interval Disabled,ENTMonitor„Stats„Clear-All Clear ALL Stats Clear all Stored Stats? No Yes Monitor„AUPC Monitor AUPCfor grouped as modem only Monitor„CnC Monitor CARRIER-IN-CARRIER CnC Monitor„ODU Monitor ODU for L-Band Unit only ODU LNB Test Mode Bist ENT Spec-Analyzer Mode Norm if 2 Dig 2 I/O 2 RF Tx-CW Tx1-0 ENTTest Norm If Loop Dig Loop RF Loop TX-CWTX-1,0 Bist BERT-Config BERT-Mon BERT-Control ENT Bert Config Tx=ON Rx=ON Tx-Pat=2047 Rx-Pat=2047Bert Monitor Errs=0000253 BER=8.5E-07 Bert Control 10E-3Err=OFF Restart=NO SyncThres=256 Mode Config Spectrum Analyzer ModeConfig Spectrum Analyzer CenterFreq Span Spectrum Analyzer If Loopback Info„Rem Remote Control Information Info InformationInfo Rem Tx Rx Buffer Frame Interface Mask Ref ID Info„Tx TX Information Tx 1140.000 05000.000 TUR 8P 17/18 S EXT -20.0 on NTx C N N Info„Rx RX Information Rx 1140.000 05000.000 TUR 8P 17/18 D RX BUF +/-32k NRx C N N Demod Sweep Acquisition range Buffer Enabled Tx=Rx ENT Info„Buffer Buffer InformationInfo„Frame Framing and Edmac Information Info„Interface Interface Information Info„Mask Alarm Mask Information Info„Ref Frequency ReferenceInfo„ID Circuit Identification Character TST Message Save/Load„Save Save Configuration No YES Save/Load„Load Load Configuration New Config has been Loaded From LocationEmpty ENT Contains No Data! ENT Utility„RxBuffer Buffer Recenter Utility„Clock REAL-TIME ClockUtility RxBuffer Clock Ref ID Display Firmware Fast Real-Time Clock , ,ENT Time=120000 Date24/04/03 Utility„Ref Reference Adjust Warm-up delay ENTUtility„ID Circuit Identification Internal Freq Utility„Display Display Brightness Utility„Firmware Firmware Current Active Image #1 Next Reboot Image #1 #2 Update Cpld to v1.x.x? No Yes ENTProgramming Cpld Utility„FAST Fast Code Options Fast View Options ENT Redun Not Installed Edit 20 digit Fast Code 00000000000000000000 ENT Forward Error Correction Options Viterbi Viterbi Decoding SummaryFor Against Reed-Solomon Outer Codec Closed Network Modes Concatenated R-S Coding Summary Trellis Coding PSK/TCM Coding Summary Turbo Product Codec Hardware Option Introduction Evolution of TPC in Comtech Products End-to-End Processing Delay Turbo Product Coding processing delay comparisonAvailable TPC Modes Comparison of all TPC Modes Turbo Product Coding Summary Viterbi Decoding BER Viterbi with PSK/TCM Rate 2/3 Decoding, withWithout 219, 201 RS Outer Code CDM-Qx Satellite Modem Forward Error Correction Options Comtech Turbo Product Codec Rate 3/4 QPSK, 8-PSK 16-QAM Comtech Turbo Product Codec Rate 7/8 QPSK, 8-PSK 16-QAM Comtech Turbo Product Codec Rate 21/44 Bpsk and Rate 5/16 Bpsk Turbo BPSK/QPSK BER Page Edmac Channel Theory Of Operation M&C Connection Setup Summary This page is intentionally left blank Automatic Uplink Power Control Setting Aupc Parameters Target Eb/NoMax Range Alarm Demod UnlockCompensation Rate Monitoring DoubleTalk Carrier-in-Carrier Page Transponder Utilization with and without CnC→ Page Redundancy CDM-Qx Satellite Modem Revision Redundancy MN/CDMQx.IOM 10-2 Management Ethernet Management Interface Protocols Web Server Http Interface Web Web Server Menu Tree Web Server Menu TreeLevel 11-4 11-5 11-6 11-7 Snmp Interface Management Information Base MIB Files Snmp Community Strings Snmp Traps Alarms and Faults SNMPv2 notifications Telnet Interface 11-11 11-12 Page Page Modulator FEC Power Spectral Density Referred to symbol rateComtech EF Data CDM-Qx Transmit Demodulator ViterbiPSK/TCM Codec Turbo Product HIGHER-ORDER ModulationCoding Automatic Uplink Power Control Future Hssi Data Rate Ranges Framing Summary Future MiscellaneousFCC Page Ethernet FTP upload procedure Appendix B. Flash Upgrading Construction Sector CDM-Qx Satellite Modem Revision Flash Upgrading MN/CDMQx.IOM Appendix C. Remote Control RS-485 RS-232 Basic Protocol Packet Structure Start Of PacketController-to-target Example 0135/TRQ=70.2345CR Target-to-controller Address Instruction CodeSlot Address Instruction Code Qualifier ‘=’ code Target to Controller is used in two ways $ code target-to-controller is only used as follows Remote Commands Message ArgumentsEnd Of Packet CDM-Qx Satellite Modem Revision Remote Control MN/CDMQx.IOM TX Remote Commands TCR= TCR?TCR TCR# TSI= TSI= TSI?TSI TSI# TSI$ TCK= TCK= TCK?TCK TCK# RFQ= RFQ= RFQ?RFQ RFQ# RFQ$ RMD= RMD= RMD?=BPSK RMD =QPSK RMD# RDR= RDR= RDR?RDR RDR# RSW= RSW= RSW?RSW RSW# EBA= EBA= EBA?EBA EBA# EBA$ ITF= ITF= ITF?ITF ITF# ESA= ESA= ESA?ESA ERF= TST= TST= TST?TST TST# AUP= AUP= AUP?AUP AUP# LBO= LBO= LBO?LBO LBO# Hssi HHC=HHC? HHC Applies to CST= CST?CST CST# TIM= TIM= TIM?TIM TIM# IRM= IRM = IRM?IRM IRM# FBU= FBU= FBU?FBU FBU# CSD= CSD?CSD CSD# Query Commands EID? Bytes UID? =Change in fault FLT? WHO? REB? CC is Fault Code numbers, as in FLT? Or Infor Code, which RNE= RNS=CR RSL? RX BERCRM? CDM? CFM? SWR?FRW? IMG= IMG= IMG?IMG IMG# ITP? Bulk Commands OGC= OGC= OGC?OGC OGC# Arguments For Command or Response to Query BAD=Band Unit Only BOE= BCH=BCL= BUC LO BLO= BUC BUT?BPA? BSV? Parameter Instruction Type Code Qualifier LNB Power Control Band Unit Only Parameter Instruction Type Code Qualifier Parameter Command Instruction Type Code Qualifier BCT= BCT= BCT?BCT# BCT$ SPM= SPF=SPS= SPM= SPM? DNI= DNI= DNI? DNI# DNI$ DNI Parameter Instruction Type Code Qualifier Drop Timeslot DTS=Applies to Cards grouped As modem CDM-Qx Satellite Modem Revision Remote Control MN/CDMQx.IOM Performance Characterization Carrier-in-CarrierDescription Degradation Due To Carrier Spacing Figure D-1. Adjacent Carrier a As Tested and BAs Plotted Carrier Spacing For 20% RolloffDegradation ≤ 0.5 dB Carrier Spacing For 35% Rolloff PSK 3/4 Turbo, α = 35% Selecting The Adjacent Carrier Curve Figure D-5. Adjacent Carrier Cases Curve To Use In Figure D-2, Error Carrier-in-Carrier Ratio CnC RatioCase Desired Adjacent Carrier Found., or D-4 Figure D-7. CnC Ratio For Qpsk and 8-PSK Symbol Rate Ratio CnC Carrier Offset1st CnC Example Adjacent Carriers, CnC Ratio and Rain Fade DL Fade UL Fade Site a Site B Site a Site BComment Per Figure D Figure D-10. Link With Fading At Site a 2nd CnC Example CnC Ratio With Asymmetric Links Link parameters and results are summarized in the table Parameters Site a Site B 3rd CnC Example Asymmetric Link With Rain Fade Eb/No Degradation At Site a Parameter Due To Fade AtPer Figure D- Qpsk Conclusion Eb/No Degradation At Site B Parameter Due To Fade At Metric Conversions 480 333 2200 Phone 480 333 2161 FAX