DoubleTalk Carrier-in-Carrier | Mocomtech CDM-QX guide

Chapter 9. DoubleTalk™

Carrier-in-Carrier®

OPERATION

The Modem optionally incorporates a proprietary technology licensed from Applied Signal Technology, Inc. called DoubleTalk™, hereafter referred to as DoubleTalk Carrier-In-Carrier (CnC) when implemented in Comtech EF Data modems. CnC essentially allows two carriers to share the same channel.

Traditional full-duplex links utilize frequency division multiplexing to allow communications in two directions. This requires allocating two frequency bands, one for each direction (A and B). CnC allows the two carriers to reside on the same center frequency allowing the duplex link to consume half the bandwidth as that of FDMA.

All of the following requirements must be met before carrier in carrier will function correctly.

1.Both of the earth stations must be able to see each other’s carriers.

2.The modulator and demodulator must be “grouped” together for CnC to operate.

3.The relative power level between the two carriers must be < ± 10 dB of each other. For optimal performance the carriers should be < ± 7 dB of each other.

4.The symbol rate ratio of the two carriers should be < 3:1 (either way).

It is recommended that the user start with the traditional FDMA configuration as shown in Figure 10-1. This allows the user to establish the links, make sure the modems and RF equipment are all functioning correctly and that a reasonable Eb/No has been set in each direction for the modulation and code rate selected.

Then the modem generating the “B” carrier in this example should be relocated in frequency to be “on top” of carrier “A”. At this point the demodulator-receiving carrier “A” will loose lock. The carrier in carrier function must now be enabled in the Rx configuration menus. Once CnC is turned on the demodulator will perform a search for a

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Mocomtech CDM-QX operation manual DoubleTalk Carrier-in-Carrier

Contents

Revision CDM-QxPage Acquisition range Errata aPage Errata B Page Rx Rs n/k ENT IESS-310 network 219/201 Errata CPage Tx Rs n/k ENT IESS-310 network 219/201 Errata DPage Part Number MN/CDMQx.IOM Revision January 20,2007 Customer Support Table of Contents Chapter Functional Description External Connections Comparison of all TPC Modes Evolution of TPC in Comtech Products Management Information Base MIB Files 11-1 About this Manual Electrical Safety International Symbols CE Mark Warranty Policy CDM-Qx Satellite Modem Revision Preface MN/CDMQx.IOM Xii CDM-Qx/QxL Introduction Features DoubleTalk Carrier-in-Carrier Software Flash UpgradingVerification Remote Control Data InterfacesTurbo Product Coding Major Assemblies Assembly Description Fast Fast Options and Hardware Options Hardware Options Fast Accessible OptionsFast System Theory Implementation Supporting Hardware and Software Compatibility Band CDM-Qx Satellite Modem Revision Introduction MN/CDMQx.IOM Unpacking Installation Mounting Optional Rear-Mounting Installation Bracket Installation of the Optional Mounting Brackets Observe the following ConfigurationSelect Internal if Loop Connect External Cables Functional Description Page Modem Block Diagram Page Connections LED Front Panel Rear Panel Rear PanelPage IEC Modem Rear Panel ConnectorsName Ref. Desig Connector Type Function BNC RF Output 75 or 50Ω Use for 2-wire RS-485 operation 2 M&C 10/100BaseT Connector3 485/232 Connector Remote Control Interface Connector Pin Assignments Alarms Connector Alarm Interface Connector Pin AssignmentsPin # Signal Function Name Pin # Signal Function Name Direction Balanced G.703 Connector Tx/Rx ConnectorUnbalanced G.703 Tx/Rx Connectors Balanced G.703 Interface Connector Pin Assignments RS-232 Circuit # 7 RS-530 Data Interface ConnectorPin # Generic Signal Description Direction RS-422 RS Lvds Xx6. Quad E1 Data Interface J1 Connector Pin Assignments Quad E1 Data Interface Connectors AC Power Specifications RX and TX if ConnectorsAC Power Connector DC Power Connector Ground Connector This page is intentionally left blank Operation Front Panel LED Indicators LEDColor Condition Diamond Keypad Presently used on all Units ENTCLR TXF Left-Hand Display AreaModems Right Hand Display Area MD MD Redundancy RXS Accessing the Display AreaSpectrum Analyzer Right-Hand Display Area Principle Menu Tree ODU Main Menu Config Monitor Test Info Save/Load Util ODUOpening Screen Comtech EF Data CDM-Qx Firmware Version Config Remote Tx Rx Group Frame Interface Ref Mask ODU Config 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„SNMP Config„Remote„Ethernet„GatewayConfig„Remote„Ethernet„Address Config„Remote„Ethernet„MAC Config„Remote„Ethernet„SNMP„Communities Config„Remote„Ethernet„SNMP„TrapsSnmp Trap IP Addr#2 ENT Trap Community , ENT comtechTrap Version ENT SNMPv1 SNMPv2 Trap IP Addr#1 ENT Tx FEC Mod Code Data Freq On/Off Pwr Scram Clk Inv Txα Config„Tx Transmit TPC Config„Tx„FEC TX FEC TypeConfig„Tx„Mod Modulation Scheme Tx FEC Vit Vit+RS TCM+RS Tx Data Rate 05000.000kbps Sym02500.000ksps Config„Tx„Code TX Code RateConfig„Tx„Data TX Data Rate Tx Code Rate 5/16 21/44 1/2 3/4 17/18 Tx if Freq 1156.3456 MHz Config„Tx„Freq TX if Frequency Tx Common Output State Off On Config„Tx„On/Off Transmit ON/OFF ControlTx if Freq 1156.3456 MHz RF=14156.3456 ENT Tx Output State On Off RxTxInhibit Common , ENT Config„Tx„Pwr Transmit Power Level Mode Config„Tx„Pwr„Manual Manual ModeConfig„Tx„Pwr„AUPC Aupc Mode Config„Tx„Pwr„AUPC DEMOD-UNLOCK Config„Tx„Pwr„AUPC Target Eb/NoConfig„Tx„Pwr„AUPC MAX Range Config„Tx„Pwr„AUPC Alarm Config„Tx„Pwr„Combined Combined Transmit Power Config„Tx„Scram ScramblerConfig„Tx„Clk TX Clocking Mode Tx Data Sense Config„Tx„Inv TX Inversion FunctionsTx Inversion functions Spectrum Data Clock ,ENT Tx Spectral Inversion Normal Inverted RxFEC Demod Code Data Freq Acq Descram Buf Inv Misc CnC Config„Tx„Txα TX Roll-Off α factorConfig„Rx Receive Tx Roll-off 20% 35% ENT Case Rules Comment Config„Rx„FEC RX FEC TypeRx FEC Vit Vit+RS TCM+RS Rx Code Rate 5/16 21/44 1/2 3/4 7/8 17/18 Config„Rx„Demod Demodulation SchemeConfig„Rx„Code RX Code Rate Demodulation Bpsk Qpsk 8-PSK 16-QAM Rx Data Rate 05000.000kbps Sym02500.000ksps Config„Rx„Data RX Data Rate Demod Acquisition Range Config„Rx„Freq RX FrequencyConfig„Rx„Acq Demod Acquisition Range Rx if Freq1156.3456 MHz RF=12156.3456 ENT Config„Rx„Descram Descrambler Config„Rx„Buf RX Buffer Clock SourceENT Config„Rx„Misc Rx Miscellaneous Config„Rx„Inv RX Inversion Functions Config„Rx„Misc„EbNo Eb/No Alarm Config„Rx„Misc„Rxα RX Roll-Off α factorConfig„Rx„CnC CARRIER-IN-CARRIER→ Please Wait Config„Rx„CnC„Mode CnC→ Mode of OperationConfig„Rx„CnC„FrqOffs CnC Frequency Offset Please Check TX Power Level Config„Group„Modem Config„Rx„CnC„SrchDelay CnC Search DelayConfig„Rx„CnC„ReAcq CnC RE-ACQUISITION Time Config„Group Grouping MOD/DEMOD Cards Config„Group„Redundancy„Config „12 Config„Group„RedundancyConfig„Group„Redundancy„Config Config„Group„Redundancy„Config „11 Config„Frame„Unframed Unframed Config„Group„Redundancy„ModeConfig„Group„Redundancy„Mode„Manual Config„Frame Framing Mode Master Slave Edmac ModeFraming mix AUPC-Only AUPC+EDMAC Address This Slave Unit ENT Config„Frame„D&I++ D&I++Distant-end Base Address 0240 RTS/CTS operation , ENT Loop,RTS Controls Tx Out Config„Interface Data InterfaceInterface RS422 V.35 RS232 Hssi ASI G.703 QDI None HDB3 AMI 703 E1 Line Code HDB3 AMI , ENT T1 Line Length Feet HDB3 AMI Frequency Reference Internal MHz ENT Config„Ref Reference OscillatorConfig„Mask Mask Alarm Mask Transmit Receive Reference BUC LNB ,ENT AGC Alarm Tx Alarm Mask Tx-FIFO BPV Tx-AIS ENTTx-FIFO Alarm ENT Active Masked Rx Alarm Mask AGC Eb/No Rx-AIS Buffer Reference Alarm BUC AlarmLNB Alarm BUC LNB Config„ODU Outdoor Unit for L-Band Unit OnlyConfig„ODU„BUC Block Upconverter BUC ODU BUC M&C Config„ODU„BUC„M&C-FSK M&C FSKConfig„ODU„BUC„M&C-FSK„Address FSK Comms Config„ODU„BUC„M&C-FSK„Address FSK Address Config„ODU„BUC„Alarm BUC Alarm Config„ODU„BUC„M&C-FSK„Tx-On/Off FSK TX-ON/OFFConfig„ODU„BUC„DC-Pwr BUC DC Power Config„ODU„BUC„10MHz BUC 10MHz Power-On Delay Config„ODU„BUC„Delay BUC DelayBUC Current Alarm Upper Limit1200mA BUC Current Alarm Lower Limit1200mA Config„ODU„BUC„Mix BUC MIX Config„ODU„BUC„LO BUC LO 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 LNB Frequency Mix Config„ODU„LNB„LO LOConfig„ODU„LNB„Mix MIX LNB Current Alarm Lower Limit 050mA ENT Monitor„Alarms„Unit Unit Alarms Monitor„Alarms Alarms Monitor„Alarms„Receive Receive Alarms Monitor„Alarms„Transmit Transmit AlarmsMonitor„Alarms„ODU Outdoor Unit Alarms Monitor„Event-Log EVENT-LOG or Stored Events Monitor„Rx-Params RECEIVE-PARAMETERS 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 Clear all Stored Stats? No Yes Monitor„Stats„Config Configure StatsStats Logging Interval Disabled,ENT Monitor„Stats„Clear-All Clear ALL Stats Monitor„CnC Monitor CARRIER-IN-CARRIER CnC Monitor„AUPC Monitor AUPCfor grouped as modem only ODU LNB Monitor„ODU Monitor ODU for L-Band Unit only 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 Bert Control 10E-3Err=OFF Restart=NO SyncThres=256 Bist BERT-Config BERT-Mon BERT-Control ENTBert Config Tx=ON Rx=ON Tx-Pat=2047 Rx-Pat=2047 Bert Monitor Errs=0000253 BER=8.5E-07 Spectrum Analyzer Mode ConfigSpectrum Analyzer Mode Config Spectrum Analyzer CenterFreq Span 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 Demod Sweep Acquisition range Info„Rx RX InformationRx 1140.000 05000.000 TUR 8P 17/18 D RX BUF +/-32k N Rx C N N Info„Interface Interface Information Buffer Enabled Tx=Rx ENTInfo„Buffer Buffer Information Info„Frame Framing and Edmac Information Character TST Message Info„Mask Alarm Mask InformationInfo„Ref Frequency Reference Info„ID Circuit Identification No YES Save/Load„Save Save Configuration Contains No Data! ENT Save/Load„Load Load ConfigurationNew Config has been Loaded From Location Empty ENT Real-Time Clock , ,ENT Time=120000 Date24/04/03 Utility„RxBuffer Buffer RecenterUtility„Clock REAL-TIME Clock Utility RxBuffer Clock Ref ID Display Firmware Fast Internal Freq Utility„Ref Reference AdjustWarm-up delay ENT Utility„ID Circuit Identification Utility„Firmware Firmware Utility„Display Display Brightness Current Active Image #1 Next Reboot Image #1 #2 Update Cpld to v1.x.x? No Yes ENTProgramming Cpld Fast Utility„FAST Fast Code Options Edit 20 digit Fast Code 00000000000000000000 ENT View Options ENT Redun Not Installed Forward Error Correction Options Viterbi Viterbi Decoding SummaryFor Against Reed-Solomon Outer Codec Concatenated R-S Coding Summary Closed Network Modes PSK/TCM Coding Summary Trellis Coding Evolution of TPC in Comtech Products Turbo Product Codec Hardware Option Introduction End-to-End Processing Delay Turbo Product Coding processing delay comparisonAvailable TPC Modes Comparison of all TPC Modes Turbo Product Coding Summary BER Viterbi Decoding Viterbi with Outer Code PSK/TCM Rate 2/3Decoding, with Without 219, 201 RS Comtech Turbo Product Codec Rate 3/4 QPSK, 8-PSK 16-QAM CDM-Qx Satellite Modem Forward Error Correction Options Comtech Turbo Product Codec Rate 7/8 QPSK, 8-PSK 16-QAM Comtech Turbo Product Codec BPSK/QPSK Rate 21/44 Bpsk and Rate 5/16 Bpsk Turbo BER Page Theory Of Operation Edmac Channel 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 Ethernet Management Interface Protocols Management Web Web Server Http Interface Web Server Menu Tree Web Server Menu TreeLevel 11-4 11-5 11-6 11-7 Management Information Base MIB Files Snmp Interface Snmp Traps Snmp Community Strings Telnet Interface Alarms and Faults SNMPv2 notifications 11-11 11-12 Page Page FEC Modulator CDM-Qx Transmit Power Spectral DensityReferred to symbol rate Comtech EF Data Turbo Product DemodulatorViterbi PSK/TCM Codec HIGHER-ORDER ModulationCoding Hssi Automatic Uplink Power Control Future Data Rate Ranges Framing Summary Future MiscellaneousFCC Page Appendix B. Flash Upgrading Ethernet FTP upload procedure Construction Sector CDM-Qx Satellite Modem Revision Flash Upgrading MN/CDMQx.IOM RS-485 Appendix C. Remote Control Basic Protocol RS-232 Example 0135/TRQ=70.2345CR Target-to-controller Packet StructureStart Of Packet Controller-to-target Address Instruction CodeSlot Address ‘=’ code Target to Controller is used in two ways Instruction Code Qualifier $ 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 =QPSK RMD# RMD=RMD= RMD? =BPSK RMD RDR# RDR=RDR= RDR? RDR RSW# RSW=RSW= RSW? RSW EBA# EBA$ EBA=EBA= EBA? EBA ITF# ITF=ITF= ITF? ITF ERF= ESA=ESA= ESA? ESA TST# TST=TST= TST? TST AUP# AUP=AUP= AUP? AUP LBO# LBO=LBO= LBO? LBO HHC HssiHHC= 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 EID? Query Commands UID? Bytes FLT? =Change in fault REB? WHO? RNE= CC is Fault Code numbers, as in FLT? Or Infor Code, which RNS=CR CDM? RSL?RX BER CRM? 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 BUC LO BLO= BOE=BCH= BCL= BSV? BUCBUT? BPA? Control Band Unit Only Parameter Instruction Type Code Qualifier LNB Power Parameter Instruction Type Code Qualifier Parameter Command Instruction Type Code Qualifier BCT$ BCT=BCT= BCT? BCT# SPM= SPM? SPM=SPF= SPS= 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 Carrier-in-CarrierDescription Performance Characterization Figure D-1. Adjacent Carrier a As Tested and BAs Plotted Degradation Due To Carrier Spacing Carrier Spacing For 35% Rolloff Carrier Spacing For20% Rolloff Degradation ≤ 0.5 dB PSK 3/4 Turbo, α = 35% Figure D-5. Adjacent Carrier Cases Selecting The Adjacent Carrier Curve Found., or D-4 Curve To Use In Figure D-2, ErrorCarrier-in-Carrier Ratio CnC Ratio Case Desired Adjacent Carrier 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 Per Figure D DL Fade UL Fade Site a Site BSite a Site B Comment Figure D-10. Link With Fading At Site a 2nd CnC Example CnC Ratio With Asymmetric Links Parameters Site a Site B Link parameters and results are summarized in the table 3rd CnC Example Asymmetric Link With Rain Fade Eb/No Degradation At Site a Parameter Due To Fade AtPer Figure D- Qpsk Eb/No Degradation At Site B Parameter Due To Fade At Conclusion Metric Conversions 480 333 2200 Phone 480 333 2161 FAX