Comtech EF Data DMD50 Installation And Operation Manual

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Comtech EF Data is an
AS9100 Rev B / ISO9001:2000 Registered Company
IMPORTANT NOTE: The information contained in this document supersedes all previously published information regarding this product. This manual is subject to change without prior notice.
Universal Satellite Modem
Installation and Operation Manual
Part Number MN-DMD50 Revision 3
Page 2
Page 3
Subject:
Errata A
Comtech EF Data Documentation Update
Revise “Trademarks” subsection in Preface to include CEFD Patents and Patents Pending note
Original Manual Part Number/Rev:
Errata Number/ PLM Document ID:
PLM CO Number: Comments:
MN-DMD50 Rev 2
ER-DMD50.EA2 C-0022887 The updated information will be incorporated into the next formal
revision of the manual.
Update the manual Preface: Revise the ‘Trademarks’ section to read (addition in bold):
Trademarks
Product names mentioned in this manual may be trademarks or registered trademarks of their respective companies and are hereby acknowledged.
See all of Comtech EF Data's Patents and Patents Pending at http://patents.comtechefdata.com.
ER-DMD50.EA2 THIS DOCUMENT IS NOT SUBJECT TO REVISION/UPDATE! PLM CO C-0022887 Page 1 of 2
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ErrataAforMNDMD50Rev2 UpdatePreface
This page is intentionally blank.
ER-DMD50.EA2 THIS DOCUMENT IS NOT SUBJECT TO REVISION/UPDATE! PLM CO C-0022887 Page 2 of 2
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Comtech EF Data Documentation Update
Manual Part Number:
Errata B
DMD50 Universal Satellite Modem
MN-DMD50
Revision:
Errata Subject:
Errata Part Number:
CO Number:
Comments:
Rev 3
Updates to registered trademarks and licenses for Raytheon Applied Signal Technology, DoubleTalk and Carrier-in-Carrier
ER-MNDMD50-EB3
C-0023089 Att ach Errata to Preface, page 1.
Note:
"Applied Signal Technology, Inc." is now "Raytheon Applied Signal Technology". All references to "Applied Signal Technology, Inc." in this manual are changed to "Raytheon Applied Signal Technology
".
Patents and Trademarks
See all of Comtech EF Data’s Patents and Patents Pending at http://patents.comtechefdata.com.
Comtech EF Data acknowledges that all trademarks are the property of the trademark owners.
®
DoubleTalk
DoubleTalk
Carrier-in-Carrier
is licensed from "Raytheon Applied Signal Technology".
®
is a registered trademark of "Raytheon Applied Signal Technology".
®
is a registered trademark of Comtech EF Data.
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Errata Page 2 of 2
This page is intentionally blank.
ER-MNDMD50-EB3 THIS DOCUMENT IS NOT SUBJECT TO REVISION/UPDATE. C-0023089
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DMD50
Universal Satellite Modem
Installation and Operation Manual
Part Number MN-DMD50
Revision 3
January 13, 2011
Copyright © 2011 Comtech EF Data. A ll rights res erved. Printed in the USA .
Comtech EF Data, 21 14 Wes t 7th St re et , Tem pe, Ariz on a 85 28 1 USA, 480.333.22 00, FAX: 480.333.2161
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Table of Contents
TABLE OF CONTENTS ............................................................................................................III
CHAPTER 1. INTRODUCTION .................................................................................. 1–1
1.1 Overview ...................................................................................................................................... 1–1
1.2 8BConfigurations ............................................................................................................................. 1–2
1.2.1 Features/Options Installed at Time of Order ......................................................................... 1–2
1.2.2 Feature Upgrades .................................................................................................................. 1–2
1.2.3 Hardware Options ................................................................................................................. 1–2
1.2.4 Factory Installed Options ...................................................................................................... 1–2
1.3 Function Accessibility ................................................................................................................. 1–2
CHAPTER 2. INSTALLATION ................................................................................... 2–1
2.1 Unpacking and Inspection .......................................................................................................... 2–1
2.2 Installation Requirements .......................................................................................................... 2–2
2.3 Mounting Considerations ........................................................................................................... 2–3
2.4 Initial Configuration Check ....................................................................................................... 2–4
2.5 Modulator Checkout ................................................................................................................... 2–5
2.5.1 Initial Power-Up .................................................................................................................... 2–5
2.5.2 Factory Terminal Setup ......................................................................................................... 2–6
CHAPTER 3. THEORY OF OPERATION .................................................................. 3–1
3.1 Modem Hardware ....................................................................................................................... 3–1
3.1.1 L-Band/IF Printed Circuit Card ............................................................................................ 3–1
3.1.2 Baseband Processing Printed Circuit Card ........................................................................... 3–2
3.1.3 Enhanced Interface Printed Circuit Card .............................................................................. 3–3
3.2 Functional Block Diagram ......................................................................................................... 3–3
3.2.1 Front Panel ............................................................................................................................ 3–4
3.2.2 Baseband Processing ............................................................................................................. 3–4
3.2.3 Tx Baseband Processing ....................................................................................................... 3–5
3.2.4 Rx Baseband Processing ....................................................................................................... 3–5
3.3 Monitor & Control (M&C) Subsystem ..................................................................................... 3–5
3.3.1 Terminal Port ........................................................................................................................ 3–6
3.3.2 Modem Remote Communications (RLLP) ........................................................................... 3–6
3.3.3 Ethernet M&C Port ............................................................................................................... 3–6
3.3.4 103BModem Monitor Status
......................................................................................................... 3–7
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3.4 Async Port / ES-ES Communications ....................................................................................... 3–7
3.5 Internal Clock .............................................................................................................................. 3–7
3.6 22BLoopback Features (Terrestr ia l & 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 29BESC 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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3.14.12 Operational References ................................................................................................... 3–37
3.14.13 Carrier-in-Carrier Link Budget Calculation .................................................................... 3–37
3.14.14 Estimating PSD Ratio ..................................................................................................... 3–38
3.14.14.1 Estimating PSD Ratio from LST .................................................................................... 3–38
3.14.14.2 Estimating PSD Ratio from Satmaster ............................................................................ 3–39
3.14.14.3 Estimating PSD Ratio Using Spectrum Analyzer ........................................................... 3–39
3.14.15 DoubleTalk Carrier-in-Carrier Specifications ................................................................. 3–40
3.14.16 Carrier-in-Carrier Summary ............................................................................................ 3–40
3.14.17 Glossary .......................................................................................................................... 3–41
3.15 Satellite Control Channel (SCC) ............................................................................................. 3–43
3.15.1 SCC Framing Structure ....................................................................................................... 3–43
3.15.2 115BAggregate Data Rate ........................................................................................................... 3–45
3.15.3 Overhead Rate Comparison ................................................................................................ 3–45
3.15.4 Actual Overhead Rate Calculation ...................................................................................... 3–46
3.15.5 SCC Overhead Channel Setup ............................................................................................ 3–47
3.16 EDMAC Satellite Framing/Deframing Mode ......................................................................... 3–48
3.17 Locating the ID Code Operationa l Pro cedure........................................................................ 3–48
3.18 Strap Codes ................................................................................................................................ 3–48
CHAPTER 4. USER INTERFACES............................................................................ 4–1
4.1 User Interfaces ............................................................................................................................ 4–1
4.2 Front Panel User Interface ......................................................................................................... 4–1
4.2.1 LCD Front Panel Display ...................................................................................................... 4–2
4.2.2 Cursor Control Arrow Keys .................................................................................................. 4–2
4.2.3 Numeric Keypad ................................................................................................................... 4–2
4.2.4 Front Panel LED Indicators .................................................................................................. 4–3
4.3 Parameter Setup .......................................................................................................................... 4–4
4.4 Front Panel Control Screen Menus ........................................................................................... 4–4
4.4.1 Main
Menus .......................................................................................................................... 4–4
4.4.2 Modulator Menu Options and Parameters ............................................................................ 4–5
4.4.3 Demodulator Menu Options and Parameters ...................................................................... 4–11
4.4.4 Interface Menu Options and Param eters ............................................................................. 4–16
4.4.5 Monitor Menu Options and Parameters .............................................................................. 4–21
4.4.6 Alarms Menu Options and Parameters ............................................................................... 4–23
4.4.7 System Menu Options and Parameters ............................................................................... 4–32
4.4.8 Test Menu Options and Parameters .................................................................................... 4–41
4.5 Terminal Mode Control............................................................................................................ 4–42
4.5.1 Modem Terminal Mode Control ......................................................................................... 4–43
4.5.2 Modem Setup for Terminal Mode ...................................................................................... 4–43
4.6 Terminal Port User Interface ................................................................................................... 4–43
4.7 Connecting the Terminal .......................................................................................................... 4–44
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4.8 Terminal Screens ...................................................................................................................... 4–45
4.9 RS485 Remote Port Interface (RL LP Prot oco l) ..................................................................... 4–45
4.9.1 Protocol Structure ............................................................................................................... 4–45
4.10 43BEthernet Remote Port Interface (SNMP & Web Browser) ................................................... 4–46
CHAPTER 5. REAR PANEL INTERFACES .............................................................. 5–1
5.1 Connections ................................................................................................................................. 5–1
5.2 Compact Flash ............................................................................................................................. 5–2
5.3 Power Input Modules ................................................................................................................. 5–3
5.3.1 AC Power Input Module ....................................................................................................... 5–3
5.3.2 DC Power Input/Switch ........................................................................................................ 5–3
5.4 Chassis Connections (Standard) ................................................................................................ 5–3
5.4.1 EXT REF (J10) ..................................................................................................................... 5–3
5.4.2 TX IF (J11) ........................................................................................................................... 5–3
5.4.3 TX L-Band IF (J12) .............................................................................................................. 5–3
5.4.4 RX IF (J13) ........................................................................................................................... 5–4
5.4.5 RX L-Band IF (J14) .............................................................................................................. 5–4
5.4.6 ALARM (J15) ....................................................................................................................... 5–4
5.4.7 EXT CLK (J16) ..................................................................................................................... 5–4
5.4.8 143B ASYNC (J17) ....................................................................................................................... 5–5
5.4.9 J18 ......................................................................................................................................... 5–5
5.4.10 EIA-530 (J19) ....................................................................................................................... 5–5
5.4.11 REMOTE (J20) ..................................................................................................................... 5–7
5.4.12 ETHERNET (J21) ................................................................................................................. 5–7
5.5 G.703 IDR/IBS Interface (Optional) ......................................................................................... 5–7
5.6 ESC ALARM (J1) ....................................................................................................................... 5–8
5.7 64K AUDIO (J2) ......................................................................................................................... 5–9
5.8 K DATA (J3) ............................................................................................................................. 5–10
5.9 G.703 BAL (J4) .......................................................................................................................... 5–10
5.9.1 SWITCH INTERFACE (J5) ............................................................................................... 5–11
5.9.2 SD (DDI) (J6) ..................................................................................................................... 5–13
5.9.3 DDO (J7) ............................................................................................................................. 5–13
5.9.4 IDI (J8)
................................................................................................................................ 5–13
5.9.5 SD (IDO) (J9) ..................................................................................................................... 5–13
5.10 Ethernet Data Interface (Optional) ......................................................................................... 5–13
5.11 High-Speed Serial Interface (HSSI) (Optional) ...................................................................... 5–14
5.12 HSSI (J6) .................................................................................................................................... 5–14
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5.13 ASI/DVB/M2P Interface ( Opt iona l) ........................................................................................ 5–15
5.13.1 ASI IN (J1) .......................................................................................................................... 5–15
5.13.2 ASI OUT (J2) ...................................................................................................................... 5–15
5.13.3 DVB/M2P IN (J3) ............................................................................................................... 5–15
5.13.4 DVB/M2P OUT (J4) ........................................................................................................... 5–17
5.14 Ethernet Data Interface (Optional) ......................................................................................... 5–18
5.15 HSSI / G.703 .............................................................................................................................. 5–18
5.15.1 64K AUDIO (J2) ................................................................................................................. 5–19
5.15.2 8K DATA (J3) .................................................................................................................... 5–20
5.15.3 G.703 BAL (J4)................................................................................................................... 5–20
5.15.4 ESC ALARM (J5) ............................................................................................................... 5–21
5.15.5 161BSD (DDI) (J6) ..................................................................................................................... 5–22
5.15.6 162BDDO (J7) ............................................................................................................................. 5–22
5.15.7 IDI (J8) ................................................................................................................................ 5–22
5.15.8 SD (IDO) (J9) ..................................................................................................................... 5–22
5.16 HSSI / Ethernet (J1) .................................................................................................................. 5–22
5.17 Ethernet Data Interface ............................................................................................................ 5–23
5.18 GigE Interface ........................................................................................................................... 5–23
CHAPTER 6. MAINTENANCE AND TROUBLESHOOTING ..................................... 6–1
6.1 Periodic Maintenance ................................................................................................................. 6–1
6.1.1 Clock Adjustment ................................................................................................................. 6–1
6.2 Troubleshooting .......................................................................................................................... 6–2
6.2.1 Alarm Faults .......................................................................................................................... 6–2
6.2.1.1 Major Tx Alarms ............................................................................................................... 6–2
6.2.1.2 Major Rx Alarms .............................................................................................................. 6–3
6.2.1.3 Minor Tx Alarms .............................................................................................................. 6–3
6.2.1.4 Minor Rx Alarms .............................................................................................................. 6–3
6.2.1.5 Drop and Insert Alarms ..................................................................................................... 6–4
6.2.1.6 C
ommon Major Alarms .................................................................................................... 6–4
6.2.2 Alarm Masks ......................................................................................................................... 6–5
6.2.2.1 Active Alarms ................................................................................................................... 6–5
6.2.2.1.1 Major Alarms ....................................................................................................................... 6–5
6.2.2.1.2 Minor Alarms ....................................................................................................................... 6–5
6.2.2.1.3 Common Equipment Faults ................................................................................................. 6–6
6.2.2.2 Latched Alarms ................................................................................................................. 6–6
6.2.2.3 Backward Alarms .............................................................................................................. 6–6
6.3 IBS Fault Conditions and Actions ............................................................................................. 6–6
CHAPTER 7. TECHNICAL SPECIFICATIONS .......................................................... 7–1
7.1 Data Rates .................................................................................................................................... 7–1
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7.2 Modulator .................................................................................................................................... 7–1
7.3 Demodulator ................................................................................................................................ 7–2
7.4 Plesiochronous Buffer ................................................................................................................. 7–3
7.5 Monitor and Control ................................................................................................................... 7–3
7.6 DMD50 Drop and Insert (Optional) .......................................................................................... 7–3
7.7 Terrestrial Interfaces .................................................................................................................. 7–3
7.8 IDR/ESC T2/E2 Interface (Optional) ........................................................................................ 7–3
7.9 IDR/ESC T3/E3/STS1 Inter face (Optional) ............................................................................. 7–3
7.10 IBS/Synchronous Interface (Standard) ..................................................................................... 7–4
7.11 High-Speed Serial Interface (HSSI) .......................................................................................... 7–4
7.12 ASI ................................................................................................................................................ 7–4
7.13 DVB/M2P ..................................................................................................................................... 7–4
7.14 Ethernet Data Interface (Optional) ........................................................................................... 7–4
7.15 Gigi Ethernet Data Interface (Optional) ................................................................................... 7–4
7.16 HSSI / G703 T2/E2 Max ............................................................................................................. 7–4
7.17 HSSI / G703 T3/E3/STS1 Max ................................................................................................... 7–4
7.18 HSSI /ETHERNET ..................................................................................................................... 7–5
7.19 Environmental ............................................................................................................................. 7–5
7.20 Physical ........................................................................................................................................ 7–5
7.21 DMD50 Data Rate Limits ........................................................................................................... 7–6
7.21.1 Non-DVB .............................................................................................................................. 7–6
7.21.2 DVB ...................................................................................................................................... 7–8
7.22 DMD50 BER Specifications ..................................................................................................... 7–10
7.22.1 BER Performance (Viterbi) ................................................................................................ 7–10
7.22.2 BER Performance (Sequential) ........................................................................................... 7–11
7.22.3 BER Performance (Viterbi with Reed-Solomon) ............................................................... 7–12
7.22.4 BER Performance (Turbo) .................................................................................................. 7–13
7.22.5 BER Performance (8PSK Trellis)
....................................................................................... 7–14
7.22.6 BER Performance (8PSK Turbo) ........................................................................................ 7–15
7.22.7 BER Performance (16QAM Viterbi) .................................................................................. 7–16
7.22.8 BER Performance (16QAM Viterbi with Reed-Solomon) ................................................. 7–17
7.22.9 BER Performance (16QAM Turbo) .................................................................................... 7–18
7.22.10 BER Performance ((O)QPSK Turbo) ............................................................................. 7–19
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7.22.11 BER Performance (8PSK Turbo) .................................................................................... 7–20
7.22.12 BER Performance (16QAM Turbo) ................................................................................ 7–21
7.22.13 1/2 Rate B/O/QPSK BER Performance (LDPC) ............................................................ 7–22
7.22.14 2/3 Rate Q/8PSK/8QAM BER Performance (LDPC) .................................................... 7–23
7.22.15 3/4 Rate Q/8PSK, 8/16QAM BER Performance (LDPC) .............................................. 7–24
7.22.16 ACG Output Voltage ...................................................................................................... 7–30
APP E NDI X A. PRODUCT OPTIONS .......................................................................... A–1
A.1 Hardware Options ..................................................................................................................... A–1
A.2 G.703/IDR ESC Interface .......................................................................................................... A–1
A.3 Internal High Stability ............................................................................................................... A–1
A.4 DC Input Prime Power .............................................................................................................. A–1
A.5 ASI/RS-422 Parallel ................................................................................................................... A–1
A.6 ASI/LVDS Parallel ..................................................................................................................... A–1
A.7 HSSI ............................................................................................................................................ A–1
A.8 Ethernet Data Interface ............................................................................................................. A–2
A.9 HSSI / G.703 ............................................................................................................................... A–2
A.10 HSSI / ETHERNET ................................................................................................................... A–2
A.11 Turbo Product Code / Variable Reed-Soloman ...................................................................... A–2
A.12 Customized Options ................................................................................................................... A–2
APPENDIX B. FRONT PANEL UPGRADE PROCEDURE ......................................... B–1
B.1 Introduction ................................................................................................................................ B–1
B.2 Required Equipment ................................................................................................................. B–1
B.3 Upgrade Procedure .................................................................................................................... B–1
B.4 Demonstration Procedure ......................................................................................................... B–3
B.4.1 Running in Demonstration Mode ......................................................................................... B–5
B.4.2 Canceling Demonstration Mode .......................................................................................... B–6
APPENDIX C. CARRIER CONTROL ......................................................................... C–1
C.1 States
........................................................................................................................................... C–1
C.2 Carrier Off .................................................................................................................................. C–1
C.3 Carrier On .................................................................................................................................. C–1
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C.4 Carrier Auto ............................................................................................................................... C–2
C.5 Carrier VSat ............................................................................................................................... C–2
C.6 Carrier RTS ................................................................................................................................ C–2
APPENDIX D. WEB BROWSER SETUP GUIDE ...................................................... D–1
D.1 Introduction ................................................................................................................................ D–1
D.2 WEB Users Configuration......................................................................................................... D–2
D.3 Change Web User Name............................................................................................................ D–3
D.4 Change Authentication Password ............................................................................................. D–3
D.5 Change Access Rights ................................................................................................................ D–4
D.6 Modem Web Site ........................................................................................................................ D–4
D.7 Web Page Appearance ............................................................................................................... D–7
APPENDIX E. STRAP CODES .................................................................................. E–1
E.1 Strap Codes ................................................................................................................................. E–1
E.2 Sample Applications .................................................................................................................. E–5
E.3 Operational Case Examples ...................................................................................................... E–6
E.3.1 Case 1: IDR 8.448 Mbps, 3/4 Rate Viterbi .......................................................................... E–6
E.3.2 Case 2: IBS 1.544 Mbps, 3/4 Rate Viterbi ........................................................................... E–7
E.3.3 Case 3: Closed Network, 3/4 Rate Viterbi, IBS Overhead .................................................. E–8
E.3.4 Case 4: Loop Timing Example ............................................................................................ E–9
APPENDIX F. TCP/IP ETHERNET SETUP ................................................................ F–1
F.1 Introduction ................................................................................................................................. F–1
F.2 TCP/IP Network Configuration ................................................................................................ F–1
F.3 Network Configuration Summary ............................................................................................. F–3
F.4 Ethernet Test ............................................................................................................................... F–3
F.5 Testing the Ethernet Connection using the Ping Program (Optional) ................................... F–6
APPENDIX G. AUPC OPERATION ............................................................................ G–1
G.1 Automatic Uplink Power Control (AUPC Operation) ........................................................... G–1
G.1.1 Radyne AUPC ...................................................................................................................... G–1
G.1.2 EF AU
PC ............................................................................................................................. G–2
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G.1.3 Near Side AUPC .................................................................................................................. G–2
APPENDIX H. DROP AND INSERT (D&I) .................................................................. H–1
H.1 Drop and Insert (D&I) ............................................................................................................... H–1
H.1.1 Drop Only ............................................................................................................................ H–3
H.1.2 Insert Only ........................................................................................................................... H–3
H.1.3 Mode Selection .................................................................................................................... H–4
H.1.3.1 PCM-30 ............................................................................................................................ H–4
H.1.3.2 PCM-30C ......................................................................................................................... H–4
H.1.3.3 PCM-31 ............................................................................................................................ H–5
H.1.3.4 PCM-31C ......................................................................................................................... H–5
H.1.3.5 T1-D4/T1-D4-S ................................................................................................................ H–5
H.1.3.6 T1-ESF/T1-ESF-S ............................................................................................................ H–5
H.1.4 Multidestinational Systems .................................................................................................. H–5
H.1.5 Drop and Insert Mapping ..................................................................................................... H–6
H.2 Configuring the Modem for Drop and Insert .......................................................................... H–8
H.2.1 Data Rate .............................................................................................................................. H–8
H.2.2 Operational Network Specification ...................................................................................... H–9
H.2.3 Terrestrial Framing - Drop Mode/Insert Mode .................................................................. H–10
H.2.3.1 Insert Terrestrial Frame Source ...................................................................................... H–10
H.2.4 D&I Sample Configurations and D&I Clock Setup Options ............................................. H–11
H.3 D&I Maps and Map Editing ................................................................................................... H–15
APPENDIX I. EFFCIENT DROP AND INSERT (D&I) ................................................. I–1
I.1 Introduction ................................................................................................................................. I–1
I.2 Prerequisite .................................................................................................................................. I–1
I.3 Efficient Drop & Insert Mode .................................................................................................... I–2
I.3.1 Calculating the Required Satellite Bandwidth ........................................................................... I–3
I.3.2 Calculating the Basic Efficient D&I Rate
.................................................................................. I–3
I.3.3 Calculating the Efficient D&I Rate with E1 Signaling .............................................................. I–3
I.3.4 Calculating the Efficient D&I Rate with Enhanced Asynchronous Overhead .......................... I–4
APPENDIX J. ETHERNET DATA INTERFACE SETUP ............................................. J–1
J.1 Configuring the modem to use the Ethernet Data Interface (Optional) ................................ J–1
J.1.1 Ethernet Flow Control ............................................................................................................... J–1
J.1.1.1 Half-Duplex Flow Control ................................................................................................ J–2
J.1.1.2 Full-Duplex Flow Control ................................................................................................. J–2
J.1.2 Ethernet Daisy Chain ................................................................................................................ J–2
J.1.3 Ethernet QOS Type ................................................................................................................... J–2
J.1.4 Ethernet QOS Queue ................................................................................................................. J–2
J.1.5 Setting Up The DMD20/DMD20 LBST Ethernet Bridge To Operate Like A FIFO............... J–3
J.1.6 Packet Statistics ........................................................................................................................ J–4
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Notes:
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PREFACE
About this Manual
This manual describes th e installation and operati on for the Radyne DMD50. T his is a technical document intended for earth station engineers, technicians, and operators responsible for the operation and maintenance of the DMD50.
Reporting Comments or Suggestions Concerning this Manual
Comments and suggestio ns regarding the c ontent an d design of this m anual will be appreciate d. To submit comments, please contact the Comtech EF Data Technical Publications Department:
TechnicalPublications@comtechefdata.com
Trademarks
Copyright
Product names mentioned in this manual may be trademarks or registered trademarks of their respective companies and are hereby acknowledged.
2011, Comtech EF Data This manual is proprietary to Comtech EF Data and is intended for the exclusive use of Comtech EF Data’s customers. No part of this document may in whole or in part, be copied, reproduced, distributed, translated or reduced to any electronic or magnetic storage medium without the express written consent of a duly authorized officer of Comtech EF Data
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DMD50 Universal Satellite Modem Revision 3 Preface MN-DMD50
Conventions and References
Related Documents
The following documents are referenced in this manual:
EN300-421 and EN301-210 ETSI
ETSI EN302-307
INTELSAT Earth Station Standar ds IESS-308, -309, -310, and -315
EUTELSAT SMS
Metric Conversion
Metric conversi on inf orm atio n is loc ated o n the i nside b ac k cover of this m anu al. T his inf orm ation is provided to assist the operator in cross-referencing non-Metric to Metric conversions.
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DMD50 Universal Satellite Modem Revision 3
WARNING
potentially hazardous situation that, if not avoided,
CAUTION
CAUTION indicates a hazardous situation that, if not avoided, may result in
IM P O RTA N T
IMPORTANT or NOTE indicates information critical for proper equipment
IM P O RTA N T
Preface MN-DMD50
Cautions and Warnings
WARNING indicates a could result in death or serious injury.
minor or moderate injury. CAUTION may also be used to indicate other unsafe practices or risks of property damage.
function.
Recommended Standard Designations
Recommended St andard (RS) Desig nations have been super seded by the new desi gnation of the Electronic Ind ustries Association (E IA). References to the old designations are sh own only when depicting actual text displayed on the screen of the unit (RS-232, RS-485, etc.). All other references in the manual will be shown with the EIA designations.
The user should carefully review the following information.
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The modem contains a Lithium Battery. DANGER O F EXPLOSION EXISTS i f the
with local and national regulations.
PROPER GROUNDING PROTECTION REQUIRED: The installation instructions equipment shall be connected to the protective earth connection at all times.
"Laite on liitettävä suojamaadoituskoskettimilla varustettuun
In Sweden: “Ap p araten skall anslutas till j o rdat uttag.”
CAUTION
Preface MN-DMD50
Electrical Safety
The DMD50 has bee n shown to comply with the EN 60950-1 Safety of Information Technology Equipment (including electrical business machines) safety standard.
The equipment is rated for a nominal operating range of 100 - 240 volts AC or an appropriately equipped DC option, nominal operating range is 48+/-5 volts DC . The unit has a maximum power consumption of 250 watts.
Battery
battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the manufacturer. Dispose of used batteries in accordance
Grounding
require that the integrity of the protective earth must be ensured and that the
Fuses
Therefore, it is imperative during installation, configuration, and operation that the user ensures that the unit has been properly grounded using the ground stud provided on the rear panel of the unit.
In Finland:
pistorasiaan."
In Norway: “Apparatet må tilkoples jordet stikkontakt.”
FOR CONTINUED OPERATOR SAFETY, ALWAYS REPLACE THE FUSES WITH THE CORRECT TYPE AND RATING.
The DMD50 contains no Fuses.
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DMD50 Universal Satellite Modem Revision 3
PROPER GROUNDING PROTECTION IS REQUIRED – REFER TO THE
system that has no direct connection to ground.
International Symbols
Preface MN-DMD50
Environmental
The DMD50 must not be o perated in an environment wher e the unit is exposed to precipitation; condensation; humid atmospheres above 95% RH; altitudes (unpressurized) greater than 2000 metres; excessive dust or vibration; flammable gases, corrosive or explosive atmospheres; or extremes of temperature outside the ambient range 0 to +50°C. Maximum storage temperature allowed is -20 to +70°C.
Operation in vehicles or other transportable installations that are equipped to provide a stable environment is permitted. If such vehicles do not provide a stable environment, safety of the equipment to EN 60950 may not be guaranteed.
Installation
GROUNDING ‘CAUTION’ NOTE PROVIDED ON THE PREVIOUS PAGE. The DMD50 is designed for connection to a power system that has separate ground, line and neutral conductors. The equipment is not
The installation and c onn ec tion to the l in e supply must be m ade i n compliance to local or na tio na l wiring codes and regulations.
designed for connection to a power
The DMD50 is shipped with a line inlet c able suitable for use in the countr y of operation. If it is necessary to replace this cable, ensure the replacement has an equivalent specification. Examples of acceptab le ratings for the c able include HAR, BASEC and HOXX X-X. Examples of acceptable connector ra tings include VDE, NF-U SE, UL, C SA, OVE, C EBEC, N EMKO, DEMKO , BS1636A, BSI, SETI, IMQ, KEMA-KEUR and SEV.
Symbol Definition Symbol Definition
Alternating Current
Fuse
Telecommunications Terminal Equipment Directive
In accordance with the Telecommunications Terminal Equipment Directive 91/263/EEC, this equipment should not be directly connected to the Public Telecommunications Network.
CE Mark
Protective Earth
Chassis Ground
Comtech EF Data dec lares that the DMD50 modem meets the nec essary requirements for the CE Mark.
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DMD50 Universal Satellite Modem Revision 3
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Preface MN-DMD50
RoHS Compliancy
This unit satisfies (with exemptions) the requirements specified in the European Union Directive on the Restriction of Hazardous Substance s, Di re ctiv e 2 002 /9 5/E C (E U RoHS) .
EMC (Electromagnetic Compatibility)
In accordance with European Directive 2004/108/EEC, the DMD50 has been shown, by independent testing, to comply with the following standards:
Emissions: EN 55022 C lass B - Limits and m ethods of measurement of radio interfer ence
characteristics of Information Technology Equipment.
(Also tested to FCC Part 15 Class B.) Immunity: EN 55024 – Information Technology Equipment: Immunity Characteristics, Limits, and Methods of Measurement.
Additionally, the DMD50 has been shown to comply with the following standards:
EN 61000-3-2 – Harmonic Currents Emission; EN 61000-3-3 – voltage Fluctuations and Flicker.
To ensure that the Modem continues to comply with these standards, observe the following instructions:
Connections to the transmit and receive IF ports should be made using a good quality coaxial cable. For example, RG58 or RG59 for BNC IF connectors and LMR200, LMR240 or equivilant for the L-band SMA IF ports.
All 'D' type connectors attached to the rear panel must have back-shells that provide continuous metallic s hieldin g. Cable with a conti nuous outer shie ld (either f oil or b raid, or both) must be used, and the shield must be bonded to the back-shell.
The equipment must be operated with its c o ver on a t all times. If it becomes nec es sary to remove the cover, the user should ensure that the cover is correctly re-fitted before normal operation commences.
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Warranty Policy
Comtech EF Data products are warranted against defects in material and workmanship for a specific period from the date of shipment, and this period varies by product. In most cases, the warranty period is two years. During the warranty period, Comtech EF Data will, at its option, repair or replace products that prove to be defective. Repairs are warranted for the remainder of the original warranty or a 90 day extended warranty, whichever is longer. Contact Comtech EF Data for the warranty period specific to the product purchased.
For equipment under warranty, the owner is responsible for freight to Comtech EF Data and all related customs, taxes, tariffs, insurance, etc. Comtech EF Data is responsible for the freight charges only for return of the equipment from the factory to the owner. Comtech EF Data will return the equipment by the same method (i.e., Air, Express, Surface) as the eq ui pment was sent to Comtech EF Data.
All equipment returned for warranty repair must have a valid RMA number issued prior to return and be marked clearly on the return packaging. Comtech EF Data strongly recommends all equipment be returned in its original packaging.
Comtech EF Data Corporation’s obligations under this warranty are limited to repair or replacement of failed parts, and the return shipment to the buyer of the repaired or replaced par ts .
Limitations of Warranty
The warranty does not apply to any part of a product that has been installed, altered, repaired, or misused in any way that, in the opinion of Comtech EF Data Corporation, would affect the reliability or detracts from the performance of any part of the product, or is damaged as the result of use in a way or with equipment that had not been previously approved by Comtech EF Data Corporation.
The warranty does not apply to any product or parts ther eof where t he serial number or the serial number of any of its parts has been altered, defaced, or removed.
The warranty does not cover damage or loss incurred in transportation of the product.
The warranty does not cover replacement or repair necessitated by loss or damage from any cause beyond the control of Comtech EF Data Corporation, such as lightning or other natural and weather related events or wartime environments.
The warranty does not cover any labor involved in the removal and or reinstallation of warranted equipment or parts on site, or any labor required to diagnose the necessity for repair or replacement.
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The warranty excludes any responsibility by Comtech EF Data Corporation for incidental or consequential damages arising from the use of the equipment or products, or for any inability to use them either separate from or in combination with any other equipment or products.
A fixed charge established for each product will be imposed for all equipment returned for warranty repair where Comtech EF Data Corporation cannot identify the cause of the reported failure.
Exclusive Remedies
Comtech EF Data Corporation’s warranty, as stated is in lieu of all other warranties, expressed, implied, or statutory, including those of merchantability and fitness for a particular purpose. The buyer shall pass on to any purchaser, lessee, or other user of Comtech EF Data Corporation’s products, the aforementioned warranty, and shall indemnify and hold harmless Comtech EF Data Corporation from any claims or liability of such purchaser, lessee, or user based upon allegations that the buyer, its agents, or employees have made additional warranties or representations as to product preference or use.
The remedies provided herein are the buyer’s sole and exclusive remedies. Comtech EF Data shall not be liable for any direct, indirect, special, incidental, or consequential damages, whether based on contract, tort, or any other legal theory.
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Customer Support
Refer to p. xxiv for information regarding this product’s Warranty Policy.
Contact the Comtech EF Data Customer Support Depa rtment for:
Product support or training
Reporting comments or suggestions concerning manuals
Information on upgrading or returning a product
A Customer Support representative may be reached at:
Comtech EF Data Attention: Customer Support Department 2114 West 7th Street Tempe, Arizona 85281 USA
480.333.2200 (Main Comtech EF Data number)
480.333.4357 (Customer Support Desk)
480.333.2161 FAX
To return a Comtech EF Data product (in-warranty and out-of-warranty) for repair or replacement:
Contact the Comtec h EF Data Custom er Support Departm ent. Be prepare d to suppl y the Customer Support representative with the model number, serial number, and a description of the problem.
Request a Return Material Auth orization (RMA) number from the Comtech EF Data Customer Support representative.
Pack the product in its original sh ipp in g car ton/ pac kaging to ensure that t he pr o du c t is not damaged during shipping.
Ship the product back to Comtech EF Data. (Shipping charges should be prepaid.)
Online Customer Support
An RMA number request can be requested electronically by contacting the Customer Support Department through the online support page at www.comtechefdata.com/support.asp:
Click on “Return Material Authorization” for detailed instructions on our return procedures.
Click on the “ RMA Request Form ” hyperlink, then fill out the form com pletely before sending.
Send e-mail to the Customer Supp ort Depa rtment at service@comtechefdata.com.
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Notes:
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This chapter provides an overview of the DMD50 Universal Satellite Modem. When describing the equipment, it may be referred to as “the modem”, or “the unit”.
1.1 Overview
The Radyne Universal Satellite Modem (Figure 1-1) offers the best features of a sophisticated programmable IBS/IDR and Closed Network Modem, at an affordable price.
This versatile equipment package combines unsurpassed performance with numerous user­friendly Front Panel Programmable Functions. The unit provides selectable functions for different services: Intelsat IDR and IBS, as well as closed networks. All of the configuration and Monitor and Control (M&C) Functions are available at the Front Panel. Operating parameters, such as variable data rates, FEC Code Rate, modulation type, IF Frequencies, IBS/IDR Framing and interface type can be readily set and changed at the Front Panel by earth station operations personnel.
The modem operates at all standard IBS and IDR Data Rates up to 8.448 Mbps. Selection of any data rate is provided over the range of 2.4 Kbps to 52 Mbps in 1 bps steps.
For applications requiring system redundancy, the Modem may be used with the Radyne RCS11 1:1 Redundancy Switch or the RCS20 M:N (N < 9) Redundancy Switch. An Internal Engineering Service Channel Unit is available to provide voice, data, and alarms for Intelsat IDR applications.
A full range of Industry Standard Interfaces are available. Interface types are selectable from V.35, RS-232, RS-422/-530, ITU G.703, HSSI, ASI, DVB/M2P and Ethernet Bridge.
Chapter 1. Introduction
Figure 1-1. Universal Satellite Modem Front Panel
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DMD50 Universal Satellite Modem Introduction
1.2 Configurations
The unit can be configured in the following ways:
Features and options that are installed when the unit is ordered Feature upgrades Hardware options that are installed to a unit that is sent to a Comtech facility Hardware options that the user can install at their own location
1.2.1 Features/Options Installed at Time of Order
Features installed at the time of ordering are the options pre-installed /initialized in the factory prior to shipment. These can be reviewed from the front panel. Refer to Chapter 4, User Interfaces, for information on how to view these features. Factory installed options are chassis and board configurations that are introduced during manufacture.
1.2.2 Feature Upgrades
Feature Upgrades are a simple and quick way of changing the feature set of an installed modem. Feature upgrades are how most options are implemented. Features may be purchased at any time by contacting a Comtech Corp. salesperson. Refer to Chapter 4 and Appendix D, for information on how upgrade features are enabled.
1.2.3 Hardware Options
Hardware options (refer to Appendix A) are purchased parts that can be installed into the unit at the customer’s site. A screwdriver is normally the only tool required. Please contact the Customer Service Department for information not limited to availability and to shipping costs.
Only authorized service personnel should handle and install optional hardware options.
1.2.4 Factory Installed Options
Units may also be sent to the factory for hardware option installation. Please contact the Customer Service Department for information not limited to availability and to shipping costs.
1.3 Function Accessibility
All functions can be accessed with a terminal or personal computer via a serial link for complete remote monitoring and control capability.
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Chapter 2. Installation
CAUTION
2
Remove the cardboard/foam space covering the modem.
3
4
Save the packing material for storage or reshipment purposes.
submit a damage report.
2.1 Unpacking and Inspection
Inspect shipping containers for damage. If shipping containers are damaged, keep them until the contents of the shipment have been carefully inspected and checked for normal operation. The Universal Satellite Modem and its Installation and Operation Manual are packaged and shipped in a pre-formed, reusable cardboard carton containing foam spacing for maximum shipping protection.
Do not use any cutting tool th at w ill extend more tha n 1/2 in ch in to th e co n ta ine r. This can cause damage to the modem.
Unpack and inspect the modem as follows:
Step Procedure
1
5
6
7
Cut the tape at the top of the carton indicated by OPEN THIS END.
Remove the modem, power cord, and user’s manual from the carton.
Inspect the equipment for any poss ible dam age in curre d du ring shi pment . Note: If damage is evident, contact the carrier and Comtech EF Data immediately and
Check the contents against the packing list to verify completenes s of the shipment.
Refer to the sections that follow for further installation instructions.
The Universal Satellite Modem was carefully packaged to avoid damage and should arrive complete with the following items for proper installation:
1. DMD50 Universal Satellite Modem
2. Power Cord, six foot with applicable AC Connector
3. Installation and Operation Manual
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DMD50 Universal Satellite Modem Installation
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CAUTION
CAUTION
Should the AC power cable connector be of the wrong type for the installation, either
the cable or the power connector end should be replaced.
2.2 Installation Requirements
The modem is shipped fully assembled. It does not require removal of the covers for any purpose in installation. . The power supply itself is designed for universal application using from 100 to 240 VAC, 50 to 60 Hz, 1.0A.
WARNING
There are no user-serviceable parts or configuration settings located inside the Chassis. There is a potential shock hazard internally at the power supply module. DO NOT open the Chassis under any circumstances.
Before initially applying power to the unit, it is a good idea to disconnect the transmit output from the operating ground station equipment. This is especially true if the current configuration settings are unknown, where incorrect settings could disrupt existing communications traffic.
The unit contains a Lithium Battery. DANGER OF EXPLOSION exists if the battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the manufacturer. Dispose of used batteries in accordance with local and national regulations.
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DMD50 Universal Satellite Modem Installation
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The unit CANNOT have rack slides mounted to the side of the chassis. Cooling
ventilation, particularly at the sides. In rack systems where there is high heat
PROPER GROUNDING PROTECTION REQUIRED: The installation
2.3 Mounting Considerations
The can be installed within any standard 19 inch equipment cabinet or rack. The unit is a one rack unit (RU) mounting space (1.75 inches) vertically and 19 inches of depth a nd requires a minimum rack depth of 22 inches for cabling. The rear panel of the DMD50 is designed to have power enter from the left and IF Cabling enter from the right when viewed from the rear of the unit. Data and control cabling can enter from either side based on data interface option. The unit can be placed on a table or suitable surf ace if requ ired
When mounted in an equipment rack, adequate ventilation must be provided. The ambient temperature in the rack should be between 10° and 35° C, and held constant for best equipment operation. The air available to the rack should be clean and relatively dry. The DMD50 units may be stacked one on top of the other up to a maximum of 10 consecutive units before providing one RU of space for airflow. Demodulator units should not be placed immediately above a high heat or EMF generator to ensure the output signal integrity and proper receive operation.
Do not mount the in an unprotected outdoor location where there is direct contact with rain, snow, wind or sun. The is designed for indoor applications only.
Shielded cables with the shield terminated to the conductive backshells are required in order to meet EMC directives. Cables with insulation flammability ratings of 94 VO or better are required in order to meet low voltage directives.
fans are mounted on the right-hand side of the unit. If the unit is to be mounted in a rack, ensure that there is adequate clearance for
dissipation, forced air cooling must be provided by top or bottom mounted fans or blowers. Under no circumstance should the highest internal rack temperature be allowed to exceed 50°C (122°F).
instructions require that the integrity of the protective earth must be ensured and that the equipment shall be connected to the protective earth connection at all times. Therefore, it is imperative during installation, configuration, and operation that the user ensures that the unit has been properly grounded using the ground stud provided on the rear panel of the unit.
In Finland: "Laite on liitettävä suojamaadoituskoskettimilla
varustettuun pistorasiaan."
In Norway: “Apparatet må tilkoples jordet stikkontakt.”
In Sweden: “Apparaten skall anslutas till jordat uttag.”
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DMD50 Universal Satellite Modem Installation
IM P O RTA N T
customer’s order.
IM P O RTA N T
of the strap code.
2.4 Initial Configuration Check
The is shipped from the factory with preset factory defaults. Upon initial power-up, a user check should be performed to verify the shipped modem configuration. Refer to Section 4, User Interfaces to locate and verify that the following configuration settings are correct:
Transmit (Tx) and Receive (Rx) Interface types are dependent upon the
Implementing Strap Code 26 can set the following modem configuration. Refer to Table D-1 for an explanation and tabular listing of available Strap Codes. The Frequency and Modulator Output Power are set independently
Standard Factory Configuration Settings
Modulator:
Data Rate: 2.048 Mbps Mode: Closed Network Satellite Framing: None Scrambler: V.35 (IESS) Drop and Insert: Disabled Inner FEC: 1/2 Rate Viterbi Outer FEC: Disabled Modulation: QPSK
Frequency: 70.000000 MHz Modulator Output Power: -20 dBm
Demodulator:
Data Rate: 2.048 Mbps Mode: Closed Network Satellite Framing: None Scrambler: V.35 (IESS) Drop and Insert: Disabled Inner FEC: 1/2 Rate Viterbi Outer FEC: Disabled Modulation: QPSK
Frequency: 70.000000 MHz
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DMD50 Universal Satellite Modem Installation
To lock up the modem, enter ‘IF Loopback Enable’ under the Test Menu, or connect a Loopback Cable from J11 to J13 on the rear panel of the modem.
2.5 Modulator Checkout
The following descriptions assume that the unit is installed in a suitable location with prime AC power and supporting equipment available.
2.5.1 Initial Power-Up
CAUTION
Before initial power up of the unit, it is a good idea to disconnect the transmit output from the operating ground station equipment. This is especially true if the current Modulator Configuration Settings are unknown, where incorrect settings could disrupt the existing communications traffic. New units from the factory are normally shipped in a default configuration which includes setting the transmit carrier off.
Turn on the unit by placing the Rear Panel Switch (located above the power entry connector) to the On Position. Upon initial and subsequent power-ups, the Microprocessor will test itself and several of its components before beginning its Main Monitor/Control Program. These power-up diagnostics show no results if successful. If a failure is detected, the Fault LED will illuminate.
The initial field checkout of the modem can be accomplished from the Front Panel or in the Terminal Mode. The Terminal Mode has the advantage of providing full screen access to all of the modem’s parameters, but requires a separate terminal or computer running a Terminal Program. The Terminal Mode is enabled from the front panel in the System M&C Submenus.
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DMD50 Universal Satellite Modem Installation
2.5.2 Factory Terminal Setup
The factory terminal setup is as follows:
Emulation Type: VT-100 (can be changed) Baud Rate: 19.2 K (Can be changed via Front Panel) Data Bits: 8 Parity: No Parity (Fixed) Stop Bits: 1 Stop Bit
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Chapter 3. Theor y of Operation
3.1 Modem Hardware
The modem is based on a two printed circuit card (minimum configuration) design with additional optioned printed circuit cards available for additional features. The minimum configuration consists of an L-Band/IF Assembly and a Digital Baseband Assembly. The optional printed circuit cards include a Turbo Codec printed circuit card and one of several types of Interface printed circuit card (refer to Appendix A). A block diagram of the DMD50 is shown in Figure 3-1.
3.1.1 L-Band/IF Printed Circuit Card
The L-Band/IF Printed Circuit Card consists of an analog modulation function, an analog complex downconversion, and two wide-band digital synthesizers. The block diagram of the L­Band/IF Assembly is shown in Figure 3-2.
MN-DMD50– Revision 3 3–1
Figure 3-1. Block Diagram
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DMD50 Universal Satellite Modem Theory of Operation
In the modulator, analog in-phase (I) and quadrature (Q) signals are generated on the Digital Baseband Printed Circuit Card, routed to the L-Band/IF Printed Circuit Card, and modulated at the desired frequency. The L-Band or 70/140 modulated signal is then passed through a microprocessor controlled variable attenuator providing gain control of the output signal. In the complex downconverter, the signal for demodulation is amplified and sent through a variable wideband attenuator for AGC. The gain-controlled signal is then passed through a complex downconverter to a low IF.
Figure 3-2. IF Card Block Diagram
3.1.2 Baseband Processing Printed Circuit Card
The advent of million-plus gate count FPGAs, advanced logic synthesis tools, and DSPs providing hundreds of MIPs enabled the design of a software configurable modem. Large, fast FPGAs now provide designers with what is essentially an on the fly programmable ASIC. High speed, complex digital logic functions that previously could only be implemented in dedicated integrated circuits are now downloaded from a micro-controller through a serial or peripheral interface. When a new digital logic function is needed, a new configuration file is loaded into the FPGA. There is no limit to the number of digital logic configurations available to the FPGA, aside from the amount of Flash memory available to the system microprocessor for storage of configuration files.
The Baseband Processing Printed Circuit Card provides a flexible architecture that allows many different modes of terrestrial and satellite framing, various FEC options, digital voice processing, and several different modulation/demodulation formats. Also included on the Baseband Printed Circuit Card are three synchronous interfaces, an EIA-530 Interface supporting RS-422, V.35, and RS-232. All three interfaces are provided on the same DB-25 Connector, and are selectable from the front panel.
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DMD50 Universal Satellite Modem Theory of Operation
The Baseband Printed Circuit Card also contains the Monitor and Control (M&C) Circuitry responsible for:
Programmable part setup and initialization Continuous control and adjustment of some functions Calibration Monitoring fault status Calculating and displaying measurements User monitor and control interface including front panel and remote Units configura tion and feature set
The M&C System is based on a powerful microprocessor with a large amount of Flash memory. several bus architectures are used to inter conne ct the M& C to all com ponents of the DMD50. Communication to the outside world is done via connections to the remote port, terminal port, Ethernet port, and alarm ports. The M&C runs off of software programmed into its Flash memory. the memory can be reprogrammed via the Ethernet port to facilitate changes in software.
3.1.3 Enhanced Interface Printed Circuit Card
The normal terrestrial data for the Baseband Processing Card can be re-routed to the enhanced interface card. The enhanced interface card adds a variety of connections to the modem for additional applications
3.2 Functional Block Diagram
Figure 3-3 represents the Functional Blocks. The modem is shown in a typical application with customer data, Tx/Rx RF equipment and an antenna.
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DMD50 Universal Satellite Modem Theory of Operation
Figure 3-3. Universal Satellite Modem Functional Block Diagram
3.2.1 Front Panel
The Front Panel includes a 2 x 16 backlit LCD Display, Indicator LEDs, and a Numeric Keypad (refer to Chapter 4).
3.2.2 Baseband Processing
The Baseband Processor performs all of the functions required for an IBS/IDR Framing Unit, a Reed-Solomon Codec, and an E1/T1 Drop and Insert System. In addition, the Baseband Processing Section provides for transmit clock selection and rate adaptation as well as a rate adapter and Plesiochronous/Doppler (PD) Buffer in the receive direction. A multiplexer is also provided for the SCT Clock Source for Loop Timing Applications. The transmit and receive paths may be configured independently under processor control.
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DMD50 Universal Satellite Modem Theory of Operation
3.2.3 Tx Baseband Processing
The Tx Data and Clock enters the Baseband Processor, passes through a Rate Adapting FIFO and enters the Framer/Drop Processor. In IDR, IBS, and D&I Modes, the framer adds the appropriate framing and ESC as defined in IESS-308 and 309. In D&I Mode, the framer acquires the terrestrial framing structure, E1 or T1, and synchronizes the Drop Processor. The Drop Processor extracts the desired time slots from the terrestrial data stream and feeds these channels back to the framer. The framer then places the ‘dropped’ terrestrial time slots into the desired satellite channel slots. The data is then sent to the Reed-Solomon Encoder.
When enabled, the Reed-Solomon Encoder, encodes the data into Reed-S olom on Blocks. The blocks are then interleaved and synchronized to the frame pattern as defined by the selected specification (IESS-308, IESS-309, DVB, etc.). After Reed-Solomon Encoding, the composite data and clock are applied to the BB Loopback Circuit.
3.2.4 Rx Baseband Processing
The Receive Processor performs the inverse function of the Tx Processor. Data received from the satellite passes through the BB Loopback Circuit to the Reed-Solomon Decoder to the Deframer. The Deframer acquires the IBS/IDR/DVB frame, synchronizes the Reed-Solomon Decoder and extracts the received data and overhead from the frame structure, placing the data into the PD Buffer, sending the overhead data to the UIM. The data is extracted from the buffer and is sent to the UIM. Backward Alarm indications are sent to the M&C Subsystem. In Drop and Insert Mode, the Insert Processor synchroniz es to the inc om ing terrestrial T1/E1 Data Stream, extrac ts satellite channels from the PD Buffer, and then inserts them into the desired terrestrial time slots in the T1/E1 Data Stream.
3.3 Monitor & Control (M&C) Subsystem
The modems M&C system is connected to most of the circuitry on any board contained in the modem. These connections provide status on the working condition of the circuitry as well as providing the data required for the various measurements the modem provides. The M&C processes this information and generates status indications as well as alarms when necessary. Detailed status information is available via the modems various user interfaces including the remote and terminal ports. An external summary fault is available on the RS422 Data interface
The M&C contains a high-performance microprocessor and is responsible for overall command and control of modem functions. The M&C is constantly monitoring all subsystems of the modem by performing a periodic poll routine and configures the modem by responding to commands input to the system. During each poll cycle, the status of each of the subsy stems is collected and reported to each of the external ports. Performance statistics such as Eb/No, buffer fill %, etc. are compiled. If faults are detected, the M&C will take approp ri ate acti ons to minimize the effect of such faults on the system (refer to the Fault Matrices in Chapter 6).
The modem supports the following M&C protocols:
Terminal Interface (Section 3.2.1) Remote Port Interface (Section 3.2.2) Ethernet M&C, Web Browser & SNMP (Section 3.2.3) Modem Status, Alarms & Contact Closures (Section 3.2.4)
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DMD50 Universal Satellite Modem Theory of Operation
3.3.1 Terminal Port
This port supports an asynchronous control protocol as described in Section 4. It is configured to support RS-232 signal levels. This port is intended for use in computer-based remote M&C. All functions of the modem may be monitored and controlled from this port via a common terminal connected to the Terminal Port. This function is front panel selectable.
The Terminal Mode Control allows the use of an external terminal or computer to monitor and control the modem from a full screen interactive presentation operated by the modem itself. No external software is required other than VT-100 Terminal Emulation Software (e.g. “Procomm” for a computer when used as a terminal. The Control Port is normally used as an RS–232 Connection to the terminal device. The RS-232 operating parameters can be set using the modem Front Panel and stored in Non-volatile memory for future use.
Refer to the Remote Protocol Manual (TM117) for the Terminal, Remote and
SNMP screens and protocols.
3.3.2 Modem Remote Communications (RLLP)
The Remote Port located on J20 allows for control and monitoring of parameters and functions via an RS-232 Serial Interface, or RS-485 for RLLP Protocol. ‘Equipment Remote Mode’ setup can be entered from the front panel or the Web Browser interface under the “System” menu. This requires the user to first set the Remote Port Control to “Remote” then set the Multidrop Address as needed followed by setting the Remote Interface to RS232 or RS485.
Control and status messages are conveyed between the modem and all subsidiary modems and the host computer using packetized message blocks in accordance with a proprietary communications specification. This communication is handled by the Radyne Link Level Protocol (RLLP), which serves as a protocol ‘wrapper’ for the RM&C data. Complete information on monitor and control software is contained in the following sections.
3.3.3 Ethernet M&C Port
This port is dedicated for Ethernet Communications supporting SNMP, FTP and Web Browser. The port is configured for 10 Base-T comm unicat ion s proto col s. The Ethern et M &C Interface requires a standard RJ45 Male connector. Refer to Appendix D and F for proper setup of the TCP-IP interface and Web Browser Setup.
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DMD50 Universal Satellite Modem Theory of Operation
3.3.4 Modem Monitor Status
The modems M&C system is connected to most of the circuitry on any board contained in the chassis. These connections provide status on the working condition of the circuitry as well as providing the data required for the various measurements the modem provides. The M&C processes this information and generates status indications as well as alarms when necessary. Detailed status information is available via the modems various user interfaces (front panel, remote and terminal). A summary of this information can be connected to external equipment, switches or alarms via the open collector and/or form-C fault connections
Form-C Contacts:
The UIM provides three Form-C Relays under processor control that appear at J15.
Mod Fault: De-energized when any transmit side fault is detected.
Demod Fault: De-energized when any receive side fault is detected.
Common Fault: De-energized when any fault that is not explicitly a Tx or Rx
Fault such as an M&C or Power Supply Fault.
Open Collector Faults:
The UIM provides two Open Collector Faults that appear at Pins 18 & 21 on J19. Mod Fault: Will sink up to 20 ma (maximum) until a transmit or common
fault is detected. Will not sink current if a fault is detected.
Demod Fault: Will sink up to 20 ma (maximum) until a receive or common
fault is detected. Will not sink current if a fault is detected.
The open collector faults are intended for use in redundancy switch applications in order to provide quick status indications.
3.4 Async Port / ES-ES Communications
This port is dedicated for ES-ES Communications supported by either RS232 or RS485 signal levels. The baud rate and protocol can be selected from the Front Panel. The port may be configured for a number of communications protocols. Overhead data to/from the UIM is routed to/from the framer/deframer. This port is also used by SCC Framing for the in-band data.
3.5 Internal Clock
The time and date is kept in order to ‘time-tag’ system events. User can change the Internal Clock via the front panel, Web Browser or Terminal ports.
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DMD50 Universal Satellite Modem Theory of Operation
3.6 Loopback Features (Terrestrial & IF)
The modem provides for a number of different loopbacks. The Loopback supported are:
IF Loopback – Tx IF port is looped back to the Rx IF port TX Terrestrial Loopback - Tx Data port is looped back to the Rx Data port after the
interface driver/receiver. (prior to the framing unit)
TX Baseband Loopback - Tx Data port is looped back to the Rx Data port after the
interface driver/receiver. (after the fraiming unit)
RX Terrestrail Loopback - Receive Data from the satellite is looped back for retransmission
to the satellite, providing a far end loopback. (prior to the framing unit)
RX Baseband Loopback - Receive Data from the satellite is looped back for retransmission
to the satellite, providing a far end loopback. (after to framing unit)
TX/RX Terrestrial Loopback - provides both Terrestrail loopbacks simultaneously TX/RX Baseband Loopback - provides both Baseband loopbacks simultaneously
Usage of the modems loopback capabilities in conjunction with the Ethernet
data interface can produce undersirable network loops. In order to run any
type of data test with an Ethernet interface you must utilize two modems
connected back to back. Simply using one modem and a loopback will not
produce the desired results.
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DMD50 Universal Satellite Modem Theory of Operation
MN-DMD50– Revision 3 3–9
Figure 3-4. Loopback Functional Block Diagram
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DMD50 Universal Satellite Modem Theory of Operation
Figure 3-5. Loopback Functional Block Diagram
MN-DMD50– Revision 3 3–10
Figure 3-6. Loopback Functional Block Diagram
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DMD50 Universal Satellite Modem Theory of Operation
SD
TT
Tx CLK
SRC
High Stability
Oscillator
ST
CLOCK &
DATA
EXT REF
EXTERNAL
INTERNAL
SCT CLK
SRC
REF FREQ
SRC
SCT
SCTE
TRANSMIT
RECEIVE
CLOCK & DATA
RECOVERY
EXT CLK
EXT BNC SCT SCTE RX SAT
RT
RD
SCR
BUFFER CLK
SRC
CLOCK
RECOVERY
EXT IDI
IDI
MODULATION
HIGH STABILITY
DEMODULATION
J19
J19
J10
J16
J8
CLK POL
DATA POLARITY
NORMAL INVERTED AUTO
INV. TERR&BASE
INVERT NONE
INV. BASEBAND INV. TERR DATA
DATA POLARITY
BUFFER CLK POL
NORMAL INVERTED
INV. TERR&BASE
INVERT NONE
INV. BASEBAND INV. TERR DATA
3.7 Clocking Options
The modem supports a number of different clocking options that can be recovered from the satellite or the terrestrial links. The various clocking options allow users to determine which clock will best fit their applications. Figure 3-7 gives an overview on how the modem processes the various clocks for the Tx Clock source and the Rx Buffer Clock source. Tx and Rx Clocks may be independently locked.
3.7.1 TX Clock Options
TX clock options can be recovered from the terrestrial interface, satellite interface or internally
MN-DMD50– Revision 3 3–11
generated. The allows users to select SCTE Clock (Terrestrial) or the SCT internal clock. The modem also allows user to recover the SCT Clock from the satellite (SCR) or from the modem internally. The modem allows users to select clock polarity. The Tx clock selections available are:
Figure 3-7. Clocking and Polarity Diagram
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DMD50 Universal Satellite Modem Theory of Operation
The following paragraphs define the types of clocking options available to the user at the Front Panel.
SCT (Internal Oscillator) SCTE (External Tx Te rr es t rial Clock) Rx Satellite Clock
3.7.1.1 SCTE: Serial Clock Transmit External
The SCTE clock is the Transmit Terrestrial Clock associated with the data interface. SCTE is an external clock received from the terrestrial equipment and the modem utilizes the terrestrial clock to lock the internal clock.
In Figure 3-9, the Transmit Terrestrial Data enters the modem and is clocked into a dejitter FIFO. Data is clocked out of the FIFO by the Modulator Clock. The Modulator Clock and Phase­Locked Loop (PLL), in conjunction with the Dejitter FIFO, which reduces the input jitter. Jitter reduction exceeds the jitter transfer specified in CCITT G.821.
SCTE is sometimes referred to as Tx Terrestrial Timing or Terminal Timing. Terminal Timing is reference to the RS422 synchronous interfaces.
3.7.1.2 SCT: Serial Clock Transmit
The SCT clock can be generated internally or recovered from the satellite. The SCT clock source can be used as the TX clock source, RX Buffer Clock source and the Terrestrial Terminal equipment for clocking the transmit data. If the SCT clock is recovered from the satellite, then it is referred to as SCR. SCR is also referred to as Receive Clock, Satellite Clock, or Receive Timing (RT).
When SCT clock is configured as Internal, the frequency of the clock is set the same as the Transmit Terrestrial Clock rate. If SCT clock is configured as SCR, the internal clock is set to the same rate as the incoming receive satellite clock. SCT is sometimes referred to as Internal Timing or Send Timing (ST). In the event that the satellite clock is lost, the modem will automatically switch over to the Internal Clock and revert back to SCR when activity is detected.
If SCT is selected, then Terrestrial data that is synchronous to the SCT Clock is required to be supplied by the modem. It is intended for the terminal equipment to use the SCT as its clock source. The Autophase Circuit will automatically ensure that the data is clocked correctly into the modem. Therefore, a return clock is not necessary. The Clock Polarity should be set to Auto.
3.7.2 RX Buffer Clock Options
The modem supports a number of RX Buffer clock options that can be recovered from the satellite, terrestrial links, internally or externally. The various clocking options allow users to determine which clock will best fit their applications. Figure 3-7 gives an overview on how the modem processes the various clocks for the Tx Clock and the Rx Buffer Clock. The modem allows users to select clock polarity Tx and Rx Clocks may be independently locked. The following RX Buffer clock selections are available:
Rx Satellite Clock (Recovered from Satellite) SCTE (External Tx Te rr es t rial Clock) SCT (Internal Oscillator)
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DMD50 Universal Satellite Modem Theory of Operation
EXC Clock/EXT BNC (External Clock Source) EXT IDI (Drop and Insert)
The modem handles RX Buffer clock selections based on source priority levels. The user assigns priorities to the clock sources based on source selections. Source 1 has the highest priority and Source 5 being the last resort or lowest priority. If a fallback clock is selected and activity is lost at the highest priority source, the modem will fall back to the next highest p r ior ity clock with activity. When activity resumes on a higher priority source, the modem resumes using the higher priority source
Clock Source Priority
RX SAT 1 of 5 SCTE 2 of 5 SCT 3 of 5 EXC BNC 4 of 5 EXT IDI 5 of 5
Refer to Front panel setup menus or Web Browser manual MN-DMDREMOTEOP
3.7.2.1 RX SAT Clock
The RX Sat clock is recovered from the satellite that is received from the distant end. If selected the Buffer Clock is lock to the RX sat clock.
3.7.2.2 SCTE: Serial Clock Transmit External
When SCTE is selected as the Rx Buffer clock, the modem receives the clock from the Transmit Terrestrial interface.
3.7.2.3 SCT: Serial Clock Transmit
If SCT clock is selected as the RX Buffer clock source, then it should be configured for internal. SCT is sometimes referred to as Internal Timing or Send Timing (ST).
3.7.2.4 EXT CLK/EXT BNC: External Clock, J16
The External Clock that can be selected as the RX Buffer clock source. This is a 75ohm unbalanced BNC connector. This clock source is also identified as EXT BNC. The External Clock is often used as the station master clock. The RX Clock selection can be accessed in the INTERFACE/RX SETUP menu. The clock frequency, EXT FREQ can be selected, in the Interface/General Menu.
Clock specification:
Frequency: 1 MHz to 20 MHz
Level: 0.3 Vp-p to 5 Vp-p (Sine or Square wave)
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DMD50 Universal Satellite Modem Theory of Operation
3.7.2.5 EXT IDI: Insert Data In
External IDI is used only for E1/T1 Drop and Insert applications. The available T1/E1 Frame Source selections are External, Internal, and IDI/DDO Loopback. The T1/E1 Frame Source selections can be accessed in the INTERFACE/RX SETUP menus. If Ext IDI is selec ted as the RX Buffer clock, then user must first specify T1/E1 Frame Source.
External (RX Buffer Clock recovered from the data) Internal (RX Buffer Clock recoverd from the internal clock) IDI/DDO Loopback (RX Buffer Clock recoverd from the data and looped back)
3.7.3 EXT REF: External Reference, Top BNC Port, J10
This is not actually a clock, but does have some clocking implications. When the external reference is used, the master oscillator within the modem is locked to the external reference, and the internal accuracy and stability of the unit assumes that of the External Reference. Therefore, not only are the transmit frequencies locked to the external reference, but the modem’s internal SCT Oscillator is locked to the external reference as well.
External reference port input is specified at
.3Vpp to 5Vpp (Sine or Square wave)
3.8 RS530/422/V.35 Interface (Standard)
Data must be clocked into the modem by either the SCTE or SCT Source. If SCTE is selected as the Tx Clock Source, then SCTE must be supplied to the modem on the EIA-530 port. The output of the dejitter buffer will be clocked with this source. SCT should be used if SCTE has excessive jitter.
3.8.1 G.703 Interface (Optional)
If the G.703 Interface is selected, then the Tx Clock Source will default to SCTE and the Clock Polarity will default to Auto.
Loop timing with a G.703 Interface or Asymmetrical Data Rates requires external equipment at the remote end that is capable of using the recovered RD Clock as source timing for (SCTE) SD. The modem will not manipulate the clock frequency. Therefore, the transmit and receive clock rates must be equal in order for the modem to perform loop timing.
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3.8.2 HSSI Interface (Optional)
If the HSSI Interface is selected, then the Tx Clock Source will default to SCTE and the Clock Polarity will default to Auto.
3.8.3 Ethernet Data Interface (Optional)
If the Ethernet Data Interface is selected, then the Tx Clock Source will default to SCTE and the Clock Polarity will default to Normal.
If the Ethernet Data Interface is selected, then the Buffer Clock will default to RxSat and the Buffer Clock Polarity will default to Normal.
3.9 Reed-Solomon Codec
Refer to Figure 3-8, Figure 3-9, and Table 3-1.
Utilizing a Reed-Solomon (R-S) Outer Codec concatenated with a Convolutional Inner Codec is an effective way to produce very low error rates even for poor signal-to-noise ratios while requiring only a small increase in transmission bandwidth. Typically, concatenating an R-S Codec requires an increase in transmission bandwidth of only 9 – 12% while producing a greater than 2 dB improvement in E
b/No
encoder which adds 2t = (N – K) check bytes to produce an N byte R-S block. The R-S decoder can then correct up to “t” erred bytes in the block.
3.9.1 Reed-Solomon Operation
When the Reed-Solomon Codec is enabled, data is fed to the R-S Encoding Section where it is scrambled, formed into blocks, R-S encoded, and interleaved. Unique words are added so that the blocks can be reformed in the Receiving Modem (Refer to Figure 3-8 and Figure 3-9). Data is then sent to the modulator where it is convolutionally encoded, modulated and transmitted to the satellite.
When the signal is received and demodulated by the Receiving Modem, it is fed to a Viterbi Decoder for the first layer of error correction. After error correction is performed by the Viterbi Decoder, the unique words are located and the data is deinterleaved and reformed into blocks. The R-S Decoder then corrects the leftover errors in each block. The data is then descrambled and output from the R-S Section.
. R-S is a block Codec where K data bytes are fed into the
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DMD50 Universal Satellite Modem Theory of Operation
Bandwidth
1 ]
64
(126, 112, 7)
0.125
4
115
3.9.2 Reed-Solomon Code Rate
The R-S Code Rate is defined by (N, K) where N is the total R-S block size in bytes - data + check bytes - and K is the number of data bytes input into the R-S Encoder. The transmission rate expansion required by the R-S Codec is then defined by N/K. The modem automatically sets the correct R-S code rate for IDR/IBS open network operation in accordance with the data shown in Table 3-1. The modem allows the following N and K setting: (126, 112), (219, 201), (194,
178), (225, 205).
Variable Reed-Solomon rates are available on the optional AS/5167 Super Card. Refer to Appendix A for further information.
3.9.3 Interleaving
Iinterleaving depths of 4, 8, or 12 R-S blocks are allowed. This allows burst errors to be spread over multiple blocks in order to enhance the error correcting performance of the R-S Codec. For Intelsat Network Modes, the interleaving depth is automatically set to 4 for QPSK or BPSK, or 8 for 8PSK. In Closed Network Mode, the interleaver depth can be manually set to 4 or 8, and in DVB Network Mode, the interleaver depth is automatically set to 12.
Type of Service
Small IDR
(With 16/15
O/H)
Figure 3-8. Reed-Solomon Encoder Functional Block Diagram
Figure 3-9. Reed-Solomon Decoder Functional Block Diagram
Table 3-1. Reed-Solomon Codes
Data Rate
(Kbps)
128 256 384 512 768
R-S Code
(n, k, t) 1
(126, 112, 7) (126, 112, 7) (126, 112, 7) (126, 112, 7) (126, 112, 7)
Expansion [ (n/k) -
0.125
0.125
0.125
0.125
0.125
Interleaving
Depth
4 4 4 4 4
Maximum 2 R-S
Codec Delay (ms)
58 29 19 15 10
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1024 1536
(126, 112, 7) (126, 112, 7)
0.125
0.125
4 4 8
5
(225,
(194, 178, 8)
1544
8448
(219, 201, 9)
(219, 201, 9)
0.0896
0.0896
8
8
18
3
DVB
All
(204, 188, 8)
0.0851
12
-
1. n = code length, k = information symbols and t = symbol error correcting capability.
2. Design objective.
Baud Rate Example for
Baud Rate Example for
128
64
9.6
300
256
128
19.2
600
384
192
32
600
512
256
64
1200
640
320
128
2400
768
384
192
4800
4 4 4 4
8 8
IDR (With
96 Kbps O/H)
8PSK
1544 2048 6312 8448
2048 6312
205,10) (219, 201, 9) (194, 178, 8)
(219, 201, 9) (219, 201, 9)
0.0976
0.0896
0.0899
0.0899
0.0896
0.0896
3.10 Asynchronous Overhead Operation (Framing/Multiplexer Capability)
The Asynchronous Framing/Multiplexer is capable of multiplexing a relatively low-speed overhead channel onto the terrestrial data stream resulting in a slightly higher combined or aggregate data rate through the modem. The overhead channel is recovered at the far end. This added channel is termed variously “An Overhead Channel”, ”Service Channel”, “Async Channel” or in IESS terminology an “ES to ES Data Channel.” The basic frame structure used by the multiplexer is th a t specified in the IESS-309 Standard, resulting in a 16/15 Aggregate ratio of overhead & data to data rates.
For Regular Async: (Standard IBS), the Baud Rate is approximately 1/2000 of the
Data Rate listed in Table 3-3.
For Enhanced Async: (IBS Async.), the Baud Rate is selectable, but Data Rate is
limited.
The maximum Baud Rate is 19,200 bps for IBS Async. Two software-controlled modes are designed into the card to best utilize the available bits; “Standard IBS” and “IBS (Async)”. The characteristics of the Channel Interface is also determined by the standard or Async mode.
The Async Channel can be set under software-control to either RS-232 or RS-485 mode. The pin assignments for both modes are shown in Table 5-3.
The “RS-485” Setting controls the output into tri-state when the modem is not transmitting data, allowing multiple modem outputs to be connected together.
9 7 2
<2
13
4
Table 3-2. Baud Rate Examples for Standard IBS and Enhanced Mode
Kbps
Standard IBS
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Kbps
Enhanced Mode
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DMD50 Universal Satellite Modem Theory of Operation
Baud Rate Example for
Standard IBS
Baud Rate Example for
Enhanced Mode
896
448
256
4800
1024
512
320
9600
1152
576
384
9600
1280
640
448
9600
1408
704
512
9600
1536
768
576
9600
1664
832
640
19200
1792
896
704
19200
1920
960
768
19200
1920
960
768
19200
2048
1024
832
19200
896
19200
960
19200
1024
19200
1088
19200
1152
19200
1216
19200
1280
19200
1344
19200
1408
19200
1472
19200
1536
19200
1600
19200
1664
19200
1728
19200
1792
19200
1856
19200
1920
19200
1984
19200
2048
19200
This bit is routed directly to the ES to ES Data Channel.
Kbps
Kbps
3.11 Standard IBS Mode
In the first or “Normal” mode, all bit assignments are per the IBS standard. The bits of Overhead Housekeeping byte 32 are implemented as shown in Table 3-3 below:
Table 3-3. Bits of Overhead Housekeeping
Bit 1
Bit 2 Bit 3
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ES to ES Data Channel
Frame Alignment Part of the Frame Alignment word. Backward Alarm Transmit and Receive with main processor to activate
Its data rate is 1/512th of the aggregate rate (or 1/480th of the through terrestrial data rate), and is normally used to super-sample an asynchronous data channel.
Main Alarm/LED.
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Bit 4
Multiframe Message As per IBS.
Bits 5 and 6 Bits 7 and 8
Spare Not currently utilized. Encryption
Not currently utilized.
Utilization
The ratio of the Through Terrestrial Data Channel Rate to the aggregate rate is 15/16. The standard transmit and receive channels of the ES to ES Data Channel in Standard IBS Mode are raw channels operating at the specific bit rate as controlled by the data channel rate, without buffering. In addition, no clocks are provided with this channel. Since it would be rare that the data rate provided was exactly that required for a standard rate device, the only method of communicating using this channel is to allow it to super-sample the user data.
3.12 Asynchronous Multiplexer Mode
Since many of the frame bits in the standard IBS mode are not used, an “Enhanced” Multiplexer Mode has been implemented that can be engaged under software control. Since this mode changes the use of many of the framed non-data bits, this mode is only usable when the DMD50 is at both ends of a link.
In this mode, the overhead signaling bytes 16 and 48 can be used to implement a significantly higher speed ES to ES Data Channel under software control. When implemented, this rate is 16 times that of the normal IBS standard, or 1/30 rate).
th
of the terrestrial data rate (1/32nd of the aggregate
The IBS Async mode MUST be selected for true Asynchronous channel operation to be available.
3.13 ESC Backward Alarms
When running in IDR Mode and if the modem has the ESC Option, there will be four Backward Alarms available for use by the earth stations at each end of the link (both ends must have the ESC option). These alarms are accessed via the ESC ALARMS Port. The four alarms are controlled by four relays, each having a normally open, normally closed, and a common connection. The common connections of these relays (referred to as Backward Alarm Inputs) can be connected to whichever system on the earth station that the user wishes to trigger the backward alarm.
When ground is applied to the Common (Input) Connection of one of these relays, that relay and associated backward alarm will then be in a “no fault” state. When the ground is removed, the relay and the associated Tx Backward Alarm will toggle to the faulted state. When in the faulted
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DMD50 Universal Satellite Modem Theory of Operation
state, the receive end of the link will receive that backward alarm that is initiated at the transmit end of the link.
The user can connect whichever systems on the earth stations that they desire to these Backward Alarms Relays as long as they will supply ground to the Backward Alarm Relay Input in the “no fault” condition and the ground will be removed in the “faulted” condition.
For example: the user could connect the Demod Summary Fault of the modem to the Backward Alarm 1 Input, so that if the demod went into Major Alarm (such as a Carrier Loss), Backward Alarm 1 would be transmitted to the receive end of the link. At the receive end, it would show up as Rx Backward 1 (Receive Backward Alarm 1).
3.13.1 To Disable the ESC Backward Alarms
If the ESC ALARMS Port will not be used and the Backward Alarm Indications are to be disabled, you must connect pins 10, 11, 22 and 23 to pin 1 (gnd) on ESC Alarms port.
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ENSURE THAT THE LINK IS ROBUST ENOUGH
AND ALL
3.14 DoubleTalk Carrier-in-Carrier Option
B E FOR E ATT E MP TING TO COMMIS S ION A S ATE L L ITE L INK US ING C AR R IE R ­IN-CARRIER, THE USER
MUST
FOR NOR MAL OP E R ATION. ONL Y WHE N THIS HAS B E E N DONE – SYSTEM ISSUES (E.G., ANTENNA-POINTING, C AB LING, TE R R E S TR IAL INTE R FERENCE, SATELLITE INTERFERENCE, ETC.) HAVE BEEN SHOULD THE USER ATTEMPT THE USE OF CARRIER-IN-CARRIER.
Space segment costs are typically the most significant operating expense for any satellite-based service, having a direct impact on the viability and profitability of the service. For a satellite transponder that has finite resources in terms of bandwidth and power, the leasing costs are determined by bandwidth and power used. Therefore, a satellite circuit should be designed for optimal utilization to use a similar share of transponder bandwidth and power.
The traditional approach to balancing a satellite circuit – once the satellite and earth station parameters are fixed – involves trade-off between modulation and coding. A lower order modulation requires less transponder power while using more bandwidth; conversely, higher order modulation reduces required bandwidth, albeit at a significant increase in power.
RE SOLVED –
Comtech EF Data has added a new dimension to satellite communication optimization: DoubleTalk Carrier-in-Carrier.
3.14.1 What is DoubleTalk Carrier-in-Carrier?
The Radyne DMD50 DoubleTalk Carrier-in-Carrier option utilizes a patented (US 6,859,641) signal processing algorithm developed by Applied Signal Technology, Inc. that allows both the forward and reverse carriers of a full duplex link to share the same segment of transponder bandwidth, using patented “Adaptive Cancellation.” Applied Signal uses the term DoubleTalk™, and Comtech EF Data refers to it as DoubleTalk
CnC was first introduced in Comtech EF Data products in the CDM-Qx Satellite Modem and, more recently, in the CLO-10 Link Optimizer.
The implementation of DoubleTalk Carrier-in-Carrier in the Radyne DMD50 has been further refined, and some of the limitations that existed in the CDM-Qx implementation have been overcome.
This innovative technology provides a significant improvement in bandwidth and power utilization, beyond what is possible with FEC and modulation alone, allowing users to achieve unprecedented savings. When combined with advanced modulation and FEC, it allows for multi­dimensional optimization:
Reduced operating expense (OPEX) – e.g., Occupied Bandwidth & Transponder Power;
Carrier-in-Carrier (CnC).
Reduced capital expenditure (CAPEX) – e.g., Block Up Converter/High-Power Amplifier
(BUC/HPA) size and/or antenna size;
Increased throughput without using additional transponder resources;
Increased link av ailab ili ty (margin) without u sing additional transpond er resou rces;
A combination of any of the above to meet different objectives.
Summary: When carriers share common bandwidth, up to 50% savings in transponder utilization is possible.
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DMD50 Universal Satellite Modem Theory of Operation
3.14.2 Application Requirements
The following conditions are necessary in order to operate DoubleTalk Carrier-in-Carrier:
Link must be full duplex.
A Radyne DMD50 must be used at the end of the link where the cancellation needs to
take place.
The transponder is operated as Loopback. That is, each end of the link must be able to see
a copy of its own signal in the return (downlink) path from the satellite. The looped back signal is then subtracted which leaves the signal from the distant end of the link.
DoubleTalk Carrier-in-Carrier cannot be used in spot beam systems.
The transponder needs to be “bent-pipe” – meaning no on-board processing, demodulati on,
regeneration can be employed. Demodulation/remodulation does not preserve the linear combination of the forward and return signals and the resulting reconstituted waveform prevents recovery of the original constituent sig nals.
Figure 3-1 shows a simplified conceptual block diagram of CnC processing. The two ends of the link are denoted A and B and the uplink and downlink are shown.
This performance is achieved through advanced signal processing algorithms that provide superior cancellation while tracking and compensating for the following common link impairments:
1) Time varying delay: In addition to the static delays of the electronics and the round-trip
delay associated with propagation to the satellite and back, there is a time-varying component due to movement of the satellite. The CnC module tracks and compensates for this variation.
2) Frequency offset and drift: Common sources are satellite Doppler shift, up and down
converter frequency uncertainties, and other drift associated with the electronics in the Radyne DMD50 itself. The CnC module tracks and compensates for this frequency offset and drift.
3) Atmospheric effects: Fading and scintillation can affect amplitude, phase, and spectral
composition of the signal and the degree to which it correlates with the original signal. The CnC module tracks and compensates for these atmospheric re lated im pai rments.
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DMD50 Universal Satellite Modem Theory of Operation
DMD50 Modem
DMD50 Modem Module
4) Link Asymmetries: Various asymmetries in the forward and return link can produce
differences in the relative power of the two received signal components. These can be both deterministic (static) or random (and time varying). An example of the former would be the differences resulting from antenna size/gain variations between the two ends of the link. An example of the latter would be transient power differences due to different levels of atmospheric fading in the uplinks. CnC compensates for the asymmetries, up to a certain extent.
Figure 3-10. Conceptual Block Diagram
In a number of ways, CnC carriers behave similar to conventional carriers in satellite links. They are both exposed to adjacent carriers, cross-polarization and rain fade, and exhibit impairments when any of these become too great. In addition, CnC operates in an environment where:
Carriers intentionally occupy the same spectral slot;
Performance depends upon desired and co-located interfering carrier.
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3.14.3 Operational Recommendations
The rules for CnC operation are summarized below:
Both earth stations share the same footprint so each sees both carriers;
• CnC carriers are operated in pairs;
One outbound with multiple return carriers is not allowed;
• Asymmetric data rates are allowed (no rest ric tions );
The ratio of power spectral density is normally less than 11 dB;
CnC operates with modemsnot modulators only or demodulators only.
In addition, to minimize ‘false’ acquisition, observe the following:
Use of IESS-315 V.35 Scrambler is highly recommended;
Keep the search delay range as narrow as possible – once the modem has reported the
search delay, narrow the search delay range to the nominal reported value +/- 5 ms – for example, if the modem reported delay is 245 ms, narrow the search range to say 240 – 250 ms.
Use external data source (e.g. Firebird) or internal BER tester when testing Carrier-in-
Carrier performance.
To prevent self-locking in case the desired carrier is lost, it is recommended that the two
carriers have some configuration difference – for example, use different settings for Spectrum Inversion.
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DMD50 Satellite Modem
DMD50 Satellite Modem
3.14.4 System Functionality and Operational Considerations
Figure 3-2 illustrates a conventional, full duplex satellite link where two carriers are placed in
non-overlapping channels.
Figure 3-11. Conventional FDMA Link
Figure 3-3 shows the same link using the Radyne DMD50 equipped with the DoubleTalk
Carrier-in-Carrier option. Note that now only 50% of the bandwidth is being used, as now both carriers are occupying the same bandwidth.
The transponder downlinks the composite signal containing both carriers on the same band to the Radyne DMD50 which then translates the signal to near baseband where it can be filtered (decimated) and then processed as a complex envelope signal. The Radyne DMD50 then suppresses the version of the near end carrier on the downlink side and then passes the desired carrier to the demodulator for normal processing.
To further illustrate, as shown in Figure 3-4, without DoubleTalk Carrier-in-Carrier, the two carriers in a typical full duplex satellite link are adjacent to each other. With DoubleTalk Carrier­in-Carrier, only the composite signal is visible when observed on a spectrum analyzer. Carrier 1 and Carrier 2, shown here for reference only, are overlapping, thus sharing the same spectrum.
The Radyne DMD50 CnC module operates on the near-zero sign a l before the demodul ator, a n d is waveform agnostic. This means that no prior knowledge of the underlying modulation, FEC, or any other waveform specific parameter is required in order to perform the signal suppression operation. The only caveat to this is that the waveform must be sufficient ly ra ndom.
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DMD50 Satellite Modem
DMD50 Satellite Modem
Figure 3-12. Same Link Using Radyne DMD50 and DoubleTalk
Carrier-in-Carrier
Traditional Full Duplex Link Duplex Link with DoubleTalk Carrier-in-Carrier
Figure 3-13. Duplex Link Optimization
Because acquiring the delay and frequency offset of the interfering carrier is fundamentally a correlation operation, anything deterministic in the interfering carrier (within the correlation window of the algorithm) will potentially produce false correlation peaks and result in incorrect delays and/or frequency. Normally, this is not a problem, since energy dispersal techniques are utilized in the vast majority of commercial and military modems. However, it is something that must be kept in mind when troubleshooting a system that utilizes the DoubleTalk Carrier-in­Carrier technique for signal suppression.
One possible way to mitigate false peaks is to narrow the correlation window. For example, if the delay is known to be around 240ms, set the minimum search delay to 230ms and the maximum search delay to 250ms.
As all advances in modem technologies – including advanced modulation and FEC techniques – approach their theoretical limits of power and bandwidth efficiencies, DoubleTalk Carrier-in­Carrier allows satellite users to achieve spectral efficiencies (bps/Hz) that cannot be achieved
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DMD50 Universal Satellite Modem Theory of Operation
Spectral Efficiency (bps/Hz)
Traditional
SCPC
BPSK 1/2
0.50
1.00
QPSK 1/2
1.00
2.00
QPSK 2/3
1.33
2.67
QPSK 3/4
1.50
3.00
QPSK 7/8
1.75
3.50
8-QAM 2/3
2.00
4.00
8-QAM 3/4
2.25
4.50
8-QAM 7/8
2.63
5.25
16-QAM 3/4
3.00
6.00
16-QAM 7/8
3.50
7.00
with modulation and FEC alone. Table 3-1 illustrates how DoubleTalk Carrier-in-Carrier, when used with 16-QAM, approaches the bandwidth efficiency of 256-QAM (8bps/Hz).
Table 3-4. Spectral Efficiency using DoubleTalk Carrier-in-Carrier
Modulation
and Code Rate
Carrier-in-Carrier
As shown here, DoubleTalk Carrier-in-Carrier allows equivalent spectral efficiency using a lower order modulation and/or FEC Code Rate; CAPEX is therefore reduced by allowing the use of a smaller BUC/HPA and/or antenna. And, as DoubleTalk Carrier-in-Carrier can be used to save transponder bandwidth and/or transponder power, it can be successfully deployed in bandwidth­limited as well as pow e r-limited scenarios.
3.14.5 DoubleTalk Carrier-in-Carrier Cancellation Process
The state-of-the-art signal processing technology employed via DoubleTalk Carrier-in-Carrier continually estimates and tracks all parametric differences between the local uplink signal and its image within the downlink. Through advanced adaptive filtering and phase locked loop implementations, it dynamically compensates for these differences by appropriately adjusting the delay, frequency, phase and amplitude of the sampled uplink signal, resulting in excellent cancellation performance.
When a full duplex satellite connection is established between two sites, separate satellite channels are allocated for each direction. If both directions transmitted on the same channel, each side would normally find it impossible to extract the desired signal from the aggregate due to interference originating from its local modulator. However since this interference is produced locally, it is possible to estimate and remove its influence prior to demodulation of the data transmitted from the remote location.
For the DoubleTalk Carrier-in-Carrier cancellation, it is necessary to provide each demodulator with a copy of its local modulator’s output.
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Figure 3-14. DoubleTalk Carrier-in-Carrier Signals
Referri ng to Figure 3-5: Modem 1 and Modem 2 transmit signals S1 and S2 respectively. The
satellite receives, translates, and retransmits the composite signal. The downlink signals S1* and S2*, received at Modem 1 and Modem 2 differ from the transmit signals primarily in terms of phase, frequency, and delay offsets.
Referring to Figure 3-6: For round trip delay estimation, a search algorithm is utilized that correlates the received satellite signal to a stored copy of the local modulator’s transmitted signal. The interference cancellation algorithm uses the composite signal and the local copy of S1 to estimate the necessary parameters of scaling (complex gain/phase), delay offset and frequency offset. The algorithm continuously tracks changes in these parameters as they are generally time­varying in a satellite link.
Figure 3-15. Carrier-in-Carrier S ignal Process ing Block Dia gra m
The resulting estimate of the unwanted interfering signal is then subtracted from the composite signal. In practical applications, the estimate of the unwanted signal can be extremely accurate. Unwanted interfering signal suppression of 30 dB or more has been achieved in commercial products with minimal degradation of the demodulator performance.
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Modulation
Nominal Margin*
BPSK
0.3 dB
QPSK/OQPSK
0.3 dB
8-PSK
0.5 dB
8-QAM
0.4 dB
16-QAM
0.6 dB
* Equal power and equal symbol rate for the interfering carrier and the
Adjacent Carriers, 1.3 spacing.
3.14.6 Margin Requirements
Typical interfering signal cancellation is 28 to 35 dB (depending on the product). The residual interfering signal appears as noise causing a slight degradation of the Eb/No. To compensate for the residual noise, a small amount of additional link margin is required to maintain the BER. Margin requirements depen d on the product, modulation and power ratios:
For the Radyne DMD50, the additional margin requirements are as follows:
desired carrier, i.e., 0 dB PSD ratio. Measured at IF with AWGN, +10 dBc
3.14.7 Carrier-in-Carrier Latency
Carrier-in-Carrier has no measurable impact on circuit latency.
3.14.8 Carrier-in-Carrier and Adaptive Coding and Modulation
Carrier-in-Carrier is fully compatible with VersaFEC Adaptive Coding and Modulation (ACM) mode of operation in the Radyne DMD50.
Carrier-in-Carrier combined with VersaFEC ACM can provide 100 – 200 % increa se in averag e throughput.
3.14.9 Carrier-in-Carrier Link Design
Carrier-in-Carrier link design involves finding the FEC and modulation combination that provides optimal bandwidth utilization. Just like conventional link design, it is an iterative process that involves trying different FEC and modulation combinations with Carrier-in-Carrier until an optimal combination is found.
For optimal Carrier-in-Carrier performance, it is recommended that the two carriers have similar symbol rate and power. This can be achieved by selecting appropriate MODCODs as shown in following sections.
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Satellite & Transponder
Galaxy 18 @ 123º W, 13K/13K
Earth Station 1
Phoenix, AZ – 4.6 m
Earth Station 2
Phoenix, AZ – 2.4 m
Data Rate
512 kbps / 512 kbps
3.14.9.1 Symmetric Data Rate Link
Consider the following example:
The traditional link was based on QPSK TPC 3/4 and required 0.96 MHz of leased BW. The
1
LST
summary for the traditional link is as follows:
Carrier-in-Carrier link design involved trying different Modulation & FEC Code Rates to find the optimal combination:
8-QAM, LDPC 2/3 with Carrier-in-Carrier
QPSK, LDPC 3/4 with Carrier-in-Carrier
QPSK, LDPC 2/3 with Carrier-in-Carrier
QPSK, LDPC 1/2 with Carrier-in-Carrier
1
LST is Intelsat’s Lease Transmission Plan Program.
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Link parameters and LST summary for QPSK, LDPC 2/3 with Carrier-in-Carrier is as follows:
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Allocated BW
(MHz)
Leased BW
(MHz)
Savings Compared
to Original
PSD Ratio
(dB)
1
8-QAM, LDPC 2/3
0.3584
1.1468
1.1468
-20%
2.1
2
QPSK, LDPC 3/4
0.47785
0.6734
0.6734
30%
2.1
3
QPSK, LDPC 2/3
0.53735
0.5777
0.5777
40%
2.1
4
QPSK, LDPC 1/2
0.7168
0.5184
0.7168
25%
2.1
Traditional Link
(QPSK, TPC 3/4)
CnC Link
(QPSK, LDPC 2/3)
HPA @ 4.6 m
0.7 W
0.5 W
40%
HPA @ 2.4 m
1.5 W
1.1 W
36%
The link budget summary for the different MODCOD combinations is as follows:
S. No. Modulation & FEC
PEB (MHz)
Based on this analysis, QPSK, LDPC 2/3 with Carrier-in-Carrier provides the maximum savings of 40%.
In addition to 40% reduction in Leased Bandwidth, using Carrier-in-Carrier also reduced the required HPA Power by almost 40%:
HPA Power
HPA Power Reduction
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DMD50 Universal Satellite Modem Theory of Operation
Satellite & Transponder
IS-901 @ 342º W, 22/22 (EH/EH)
Earth Station 1
Africa – 4.5 m
Earth Station 2
Africa – 3.0 m
Data Rate
3000 Mbps / 1000 Mbps
Original Link
With Carrier-in-Carrier and LDPC
Hub to
Remote
Remote To
Hub
Hub to
Remote
Remote to
Hub
Data Rate (kbps)
3000
1000
3000
1000
Modulation
QPSK
QPSK
QPSK
QPSK
FEC
TPC 3/4
TPC 3/4
LDPC 3/4
LDPC 1/2
Occupied BW (MHZ)
2.8
0.9
3.7
2.8
1.4
2.8
Power Eq. BW (MHz)
3.3
0.6
3.9
2.5
0.3
2.8
Leased BW (MHz)
3.9
2.8
27.5%
Hub HPA (W)
26.0
20.3
22%
Remote HPA (W)
10.6
6.4
40%
Occupied BW
2.8 MHz
Power Eq. BW
3.0 MHz
7.2% increase in Power Eq. BW
Leased BW
3.0 MHz
7.2% increase in Leased BW
Hub HPA
20.3 W
Remote HPA
8.3 W
30% increase in Remote power
3.14.9.2 Asymmetric Data Rate Link
As occupied (or allocated) bandwidth of a Carrier-in-Carrier circuit is dictated by the larger of the two carriers, it is strongly recommended that the smaller carrier be spread as much as possible using a lower order modulation and/or FEC, while meeting the PSD ratio spec. Spreading the smaller carrier using a lower order modulation has multiple benefits:
Lower order modulation is always more robust;
Lower order modulation uses less transponder power – this reduces total transponder, and
increases available link margin;
Lower order modulation uses less transmit power on the ground – this can significantly
reduce th e BUC/ SS PA si ze b y not only reducing the transmit EIRP, but also reducing the BUC/SSPA backoff
Consider the following example:
While the traditional link was based on QPSK, TPC 3/4 and required 3.9 MHz of leased bandwidth, the Carrier-in-Carrier link was based on QPSK, LDPC 3/4 and QPSK, LDPC 1/2 and required 2.8 MHz of leased bandwidth.
The savings summary is as follows:
Item
Total
Total
Savings
If this link was designed using QPSK, LDPC 3/4 in both directions, it would have required:
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DMD50 Universal Satellite Modem Theory of Operation
Satellite & Transponder
IS-901 @ 342º W, 22/22 (EH/EH)
Earth Station 1
Africa – 9.2 m
Earth Station 2
Africa – 4.5 m
Data Rate
2.048 Mbps / 2.048 Mbps
Original Link
With Carrier-in-Carrier and VersaFEC
Hub to
Remote
Remote To
Hub
Hub to
Remote
Remote to
Hub
Data Rate (kbps)
2048
2048
2048
2048
Modulation
8-PSK
8-PSK
QPSK
QPSK
FEC
TPC 3/4
TPC 3/4
0.803
0.803
Occupied BW (MHZ)
1.3
1.3
2.6
1.8
1.8
1.8
Power Eq. BW (MHz)
2.2
1.0
3.2
1.1
0.5
1.6
Leased BW (MHz)
3.2
1.8
44%
Hub HPA (W)
5.0
2.0
60%
Remote HPA (W)
11.6
4.7
60%
3.14.9.3 Power Limited Links
Carrier-in-Carrier can provide su bstantial sa vings even when t he original li nk is power limit ed. Spreading the carrier by using a lower modulation and/or FEC along with latest FEC such as VersaFEC can substantially reduce the total power which can then be traded with bandwidth using Carrier-in-Carrier. The concept is illustrated with the following examples:
The conventional link is using 8-PSK, TPC 3/4:
Switching to VersaFEC and using a lower order modulation – e.g., QPSK, VersaFEC 0.803 increases the total occupied bandwidth, while reducing the total power equivalent bandwidth:
Now using DoubleTalk Carrier-in-Carrier, the second QPSK, VersaFEC 0.803 carrier can be moved over the first carrier – thereby significantly reducing the total occupied bandwidth and total power equivalent bandwidth when compared to the original side-by-side 8PSK, TPC 3/4 carriers:
To continue, consider this example:
Whereas the original link used 8-PSK TPC 3/4, the Carrier-in-Carrier link used QPSK VersaFEC
0.803. The savings summary is as follows:
Item
Total
Total
Savings
Note: 1 dB HPA BO for QPSK, 2 dB HPA BO for 8-PSK, 1 dB Feed Loss. Using Carrier-in-Carrier and VersaFEC reduced the leased bandwidth by almost 44% and HPA
power by 60%
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DMD50 Universal Satellite Modem Theory of Operation
Step
Procedure
1
Turn ON the carrier at Site A. Carrier from Site B is OFF. CnC function is OFF at
2
Turn OFF the carrier at Site A. Turn ON the carrier at Site B. CnC function is OFF at
3
Using Co+No/No readings calculate PSD ratio at Site A and Site B. If it is not within
4
5
The test can be repeated for different PSD ratio and Eb/No.
3.14.10 Carrier-in-Carrier Commissioning and Deployment
Prior to commissioning a Carrier-in-Carrier link, it is critical that the link is fully tested in non Carrier-in-Carrier mode and all system issues including external interference, antenna pointing, cabling, SSPA backoff are resolved. Only after the link is robust, should the user attempt turning on Carrier-in-Carrier.
The following procedure is recommended for Carrier-in-Carrier commissioning and deployment:
both sites.
Using a spectrum analyzer, measure Co+No/No at the input to the modem
at Site A.
Using a spectrum analyzer, measure Co+No/No at the input to the modem
at Site B.
Measure/record Eb/No at Site B. Make sure there is sufficient margin to
account for CnC.
Measure/record Receive Signal Level (RSL) at Site B.
both sites.
Using a spectrum analyzer, measure Co+No/No at the input to the modem
at Site A.
Using a spectrum analyzer, measure Co+No/No at the input to the modem
at Site B.
Measure/record Eb/No at Site A. Make sure there is sufficient margin to
account for CnC.
Measure/record RSL at Site B.
specification, make necessary adjustments to bring it within specification and repeat measurements in Step (1) and (2).
Also verify that the RSL is within spec.
Now without changing the transmit power levels, turn ON both the carriers (on the same frequency) and turn CnC ON.
Measure/record Eb/No at Site A and B. Measure/record RSL at Site A and B. Now compare Eb/No in presence of 2 over lapping carriers with CnC with
Eb/No when only 1 carrier was ON. Eb/No variation should be within spec for that modulation, FEC and PSD ratio.
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Step
Procedure
1
Setup a conventional side-by-side link of the desired Eb/No:
2
Record the Eb/No as displayed by the Modems.
3
3.14.11 Validating Carrier-in-Carrier Performance
Carrier-in-Carrier performance can be easily validated by verifying that Eb/No degradation due to Carrier-in-Carrier is within published specification for the observed Power Spectral Density Ratio.
The following procedure is recommended for validating Carrier-in-Carrier performance:
Carrier-in-Carrier should be OFF. Record the Eb/No as displayed by the Modems. Observe the 2 carriers on a spectrum analyzer and record the PSD ratio.
Example Link:
Full duplex 512 kbps, QPSK, LDPC 2/3 circuit between 4.6 m and 2.4 m antennas
Recorded Eb/No = 2.6 dB (at both modems)
PSD Ratio = 1.2 dB (measured at larger Antenna)
Now relocate one of the carriers on top of the other carrier:
Enable Carrier-in-Carrier.
Calculate change in Eb/No and verif y against sp ec if ica tion.
Example Link:
Recorded Eb/No = 2.4 dB
Chan ge in Eb/N o = 0.2 dB
Eb/No Degradation (Spec.) at 1.2 dB PSD = 0.3 dB
Modem performance is within spec.
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DMD50 Universal Satellite Modem Theory of Operation
for the link budget
3.14.12 Operational References
3.14.13 Carrier-in-Carrier Link Budget Calculation
The following steps are required for calculating the link budget for a Carrier-in-Carrier Link:
1. Calculate the link budget for both carriers in the duplex link, with required CnC margin:
Find the Eb/No
corresponding to the desired BER
Add CnC Margin
Add any other
margin
Use this compiled
value as the Threshold Eb/No
2. Verify that the PDS ration is within spec for the Radyne DMD50.
3. Calculate the Allocated Bandwidth (BW) and Power Equivalent Bandwidth (PEB) for the
duplex link:
BW
PEB
Duplex Link
Duplex Link
Leased BW
= Greater of (BW
= PEB
Duplex Link
+ PEB
Carrier 1
= Greater of (BW
Carrier 1
Carrier 2
, BW
Duplex Link
Carrier 2
)
, PEB
Duplex Link
)
4. For an optimal link, the Leased Bandwidth and the Power Equivalent Bandwidth should be
equal / nearly equal.
5. Repeat the link budget process by selecting different Modulation and FEC, until the BW and
PEB is nearly balanced.
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DMD50 Universal Satellite Modem Theory of Operation
Carrier
Downlink EIRP
Symbol Rate
Power Spectral Density
A to B
27 dBW
500 ksps
-29.99 dBW/Hz
B to A
24 dBW
375 ksps
-31.74 dBW/Hz
3.14.14 Estimating PSD Ratio
PSD can be estimated from a link budget using Downlink EIRP and Symbol Rate:
PSD = Downlink EIRP – 10 * Log (Symbol Rate)
PSD Ratio Example:
PSD Ratio (@ A) = -29.99 – (-31.74) = 1.75 dB PSD Ratio (@ B) = 01.74 – (-29.99) = -1.75 dB
3.14.14.1 Estimating PSD Ratio from LST
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3.14.14.2 Estimating PSD Ratio from Satmaster
3.14.14.3 Estimating PSD Ratio Using Spectrum Analyzer
PSD Ratio or CnC Ratio can also be estimated using a Spectrum Analyzer capable of integrating the signal power in a given bandwidth.
CnC Ratio (in dB) = PowerC1 (in dBm) – PowerC2 (in dBm) PSD Ratio (in dB) = (PowerC1 – 10 log BW
= CnC Ratio – 10 log (BW
If the two carriers have same Symbol Rate / Bandwidth, then the CnC Ratio is same as the PSD Ratio.
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/ BWC2)
C1
(in Hz)) – (Power
C1
– 10 log BW
C2
(in Hz))
C2
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DMD50 Universal Satellite Modem Theory of Operation
symbol rates do not have to be equal)
BSPK/QPSK/8-PSK/8-QAM:
Maximum Symbol Rat e Ratio
3:1 (TX:RX or RX:TX)
Above 389 ksymbols/ sec: ±1 to ± (0.1Rs) kHz, up to a maximum of ± 200 kHz
Delay range
inbound) add an additional 0.3 dB
CnC ratio, in dB (ratio of absolute power, outbound interferer to desired inbound)
3.14.15 DoubleTalk Carrier-in-Carrier Specifications
Operating Mode Requires the two links to share a common carrier frequency (Outbound and Inbound
Power Spectral Density Ratio and CnC Ratio
Inbound/Outbound frequency uncertainty
Eb/No Degradation (equal Inbound/Outbound power spectral density)
Monitor Functions Delay, in milliseconds
outbound interfer er to desired inbound) 16-QAM: –7 dB to +7 dB (ratio of pow er spectral dens ity, outbound interferer to desired
inbound) Note: With asymmetric carr iers the absolute power r atio (or CnC ratio) would be
different, depen ding on the ratio of the symbol rates.
Example:
Outbound interferer = 1 Msymbols /sec Desired Inbound = 500 ksymbols/s ec Ratio of power spectral density = +7 dB Absolute power ratio (CnC Ratio) = +7dB + (10 log Outbound/desired symbol rate) =
+10 dB
Within the normal acquisition range of the demod, as foll ows:
Below 32 ksymbols/ sec: ±1 to ± (Rs/2) kHz, where Rs = symbol r ate in ksymbols/sec Between 32 and 389 ks ymbols/sec: ± 1up to a maximum of ± 32kHz
0-330 ms BPSK = 0.3dB QPSK = 0.3dB OQPSK = 0.3dB
8-PSK = 0.5dB 8-QAM = 0.4dB 16-QAM = 0.6dB For +10 dB power spectral density ratio (outbound interf erer 10 dB higher than d esired
Frequency offset (between outbound interferer and desired inbound). 100 H z resolution
–7 dB to +11 dB (ratio of pow er spectral density,
3.14.16 Carrier-in-Carrier Summary
Comtech EF Data’s DoubleTalk Carrier-in-Carrier can provide significant savings in operational expenses. The following should be considered when evaluating DoubleTalk Carrier-in-Carrier:
DoubleTalk Carrier-in-Carrier can only be used for full duplex links where the
transmitting earth station is able to receive itself.
DoubleT alk Carrier-in-Carrier can be used in both bandwidth limited and power limited
situations.
The maximum savings is generally achieved when the original link is symmetric in data
rate.
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3.14.17 Glossary
Allocated Bandwidth
Bandwidth or Allocated Bandwidth or Occupied Bandwidth is the frequency space required by a carrier on a transponder.
For example, a Duplex E1 (2.048 Mbps) Circuit with 8-PSK Modulation, FEC Rate 3/4 and 1.4 Spacing requires:
2.548 MHz = 2.048 / (3 * 0.75) * 1.4 * 2 For a 36 MHz transponder, 2.548 MHz corresponds to 7.078% Bandwidth Utilization.
Power Equivalent Bandwidth
Power Equivalent Bandwidth (PEB) is the transponder power used by a carrier, represented as bandwidth equivalent.
PEB Calculation Example:
Transponder EIRP = 37 dBW
Output Backoff (OBO) = 4 dB
Available EIRP = 37 – 4 = 33 dBW = 10
Transponder Bandwidth = 36 MHz
Power Available / MHz = 1955.26 / 36 = 54.424 W
If a carrier uses 24 dBW, its PEB = 10
= 4.532 MHz
3.3
= 1955.26 Watts
2.4
/ 54.424
This corresponds to 12.59% of available transponder power.
Leased bandwidth
Almost all satellite operators charge for the Leased Bandwidth (LBW). Leased Bandwidth or Leased Resource is the greater of the Allocated Bandwidth and Power Equivalent Bandwidth.
For example, if a carrier requires 3 MHz of Allocated BW and 4.5 MHz of PEB, the Leased Bandwidth is 4.5 MHz
Power Spectral Density (PSD)
Power Spectral Density (PSD) is the signal power per unit bandwidth: dBW / Hz or dBm / Hz For example: Signal power = 20 dBm
Signal bandwidth = 500 kHz PSD = 20 – 10 *log (500 * 1000) = -36.99 dBm / Hz
PSD Ratio
PSD ratio is the ratio of power spectral density of the interfering carrier and the desired carrier. If looking at the 2 carriers side-by-side on a spectrum analyzer:
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DMD50 Universal Satellite Modem Theory of Operation
Eb/No
Ratio of Energy per bit (Eb) to Noise density (No): Unit is dB
C/N
Carrier Power (C) to Noise (N) ratio: Unit is dB
C/No
Carrier Power (C) to Noise Density (No) ratio: Unit is dBHz
Co+No/No
Carrier Density (Co) + Noise (No) to Noise Density (No) ratio: Unit is dB
C/N = C/N
– 10 log B [whe re B is bandwidt h in H z]
o
= C/No – 10 log R [where R is data rate in bits/sec]
E
b/No
= C/N + 10 log B – 10 log R = C/N – 10 log (Spectral Efficiency)
= 10 log (10
E
b/No
((Co+No/No)/10)
– 1) – 10 log (Spectral Efficiency)
[Spectral Efficiency is in bps / Hz]
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DMD50 Universal Satellite Modem Theory of Operation
3.15 Satellite Control Channel (SCC)
The SCC format uses a variable overhead rate to transmit an asynchronous data channel in addition to the normal data channel. The SCC asynchronous mode implemented on the DMD50 is "PassThru" Mode.
3.15.1 SCC Framing Structure
Each SCC frame consists of the following:
A 10-bit synchronization pattern called the Synchronizing Word. Multiple variable length slots filled with user data. Multiple 10-bit control words that contains eight bits of in-band data (the extra two bits are
for the async start/stop).
The number of user data slots and control words per frame is selected by the SCC Control Ratio Parameter. This can be any value from 1 to 1 through 1 to 7. A higher ratio allows a lower overhead rate but since there are less Sync Words, there is a higher acquisition time.
The following examples show a control ratio of 1 to 3 and 1 to 1. Example 1 shows three Control Words for every Synchronizing Word, and Example 2 shows one Control Word for every Synchronizing Word.
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1 to 1 Control Ratio
The Control Ratio of the receiving units must match the Control Ratio of the transmitting unit.
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User Data
Rate
In-Band
Rate
Control
Ratio
Aggregate Data
Rate
Overhead
Ratio
512,000
19,200
1/7
533,974
1.043
1,024,000
19,200
1/7
1,045,974
1.021
2,048,000
19,200
1/7
2,069,951
1.011
3.15.2 Aggregate Data Rate
The aggregate data rate equals the following :
User Data Rate + In-Band Rate + Synchronizing Overhead Rate
Because SCC must adjust the overhead so that there are an equal number of user data bits in each slot, the synchronizing overhead cannot be easily calculated. However, dividing the In-Band Rate by the Control Ratio can approximate it. The following equation shows the basic calculation of this rate:
Aggregate Date Rate = User Data Rate + In-Band Rate + (In-Band Rate/Control Ratio)
User Data
Rate
In-Band
Rate
Synchronizing
Overhead
Aggregate Data Rate
As an example, given the following parameters:
User Data Rate: 1,024,000 bps In-Band Rate: 19,200 bps Control Ratio: 1 to 7
Aggregate data rate = 1,024,000 + 19,200 + (19,200/7) or approximately 1,045,942 (actually
1045974).
This gives an overhead ratio of 1,045,974/1,024,000 = 1.021
In addition, another constraint changes the actual Aggregate Data Rate. The user data slot size is limited to 2,500 bits. Because of this, the modem increases the in-band rate to reduce the user data slot size. This only happens at higher user data rates.
3.15.3 Overhead Rate Comparison
The SCC Overhead Ratio varies depending on the User Data Rate, the In-Band Rate, and the Control Ratio. This gives SCC the advantage of lower overhead rates when compared to IBS, which has a fixed overhead ratio of 16/15 or 1.067. Table 3-4 shows example overhead rates for different user data and control ratios.
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Table 3-5. Overhead Rates Examples
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3,072,000
19,200
1/7
3,093,943
1.007
4,096,000
19,200
1/7
4,117,951
1.005
6,312,000
19,200
1/7
6,337,248
1.004
6,312,000
19,200
1/3
6,337,606
1.004
6,312,000
19,200
1/1
6,350,418
1.006
3.15.4 Actual Overhead Rate Calculation
The following is the actual calculation the modem does to calculate the overhead ratio:
1. The modem calculates the minimum in-band rate to limit the size of the user data slots to 2,500 bits (the result is truncated to an integer).
Minimum In-Band = (User Data Rate * Control Ratio)/((Control Ratio + 1) * 250)
2. Using the bigger of Minimum In-Band or the selected In-Band, the modem calculates the number of bits for each user data slot (result is truncated to an integer).
Slot Bits = (User Data Rate * (Control Ratio * 10))/(In-band Rate * (Control Ratio + 1))
The actual ratio the modem uses is:
Actual Ratio = (Slot Bits + 10)/Slot Bits
Example 1: User Data Rate: 1,024,000
bps In-Band Rate: 19,200
bps Control Ratio: 1 to 7
Mini mum In-Band = (1,024,000 * 7)/((7 +
1) * 250) = 3,584
(less than In-Band Rate)
Slot Bits = (1,024,000 * (7 * 10))/(19,200 * (7 + 1)) = 466
Actual Ratio = (466 + 10)/466 = 1.021
Example 2: User Data Rate: 6,312,000
bps In-Band Rate: 19,200 bps Control Ratio: 1 to 7
Mini mum In-Band = (6,312,000 * 7)/((7 +
1) * 250) = 22,092 (
more than In-Band Rate)
Slot Bits = (6,312,000 * (7 * 10))/(22,092 * (7 + 1)) = 2,500
Actual Ratio = (2,500+ 10)/2,500= 1.004
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3.15.5 SCC Overhead Channel Setup
1. Set the Framing Mode (located under Mod and Demod Data Menus) to SCC. After doing this, two new menus will appear to the right of the Framing Menu, for both the Mod and Demod. The new menus will be:
SCC CTL RATIO SCC INBAND RATE
2. Set the desired SCC control ratio:
SCC CTL RATIO {1/1, 1/2, 1/3, 1/4, 1/5, 1/6, 1/7}
This allows the user to simulate the framing used by the Satellite Control Channel Option (Pass-Thru Mode only). The SCC CTL RATIO is the ratio of overhead in-band data to synchronizing words.
3. Set the desired SCC in-band rate:
SCC INBAND RATE {300 to 200000}
This allows the user to request the rate of in-band data for the overhead channel. This sets the overhead amount only. The actual amount of data that can be passed through the overhead channel will be set under “ES Baud Rate” (see Step 6 below).
4. Under the Interface > General menus, locate the TX ASYNC MODE (menu).
5. Under the TX ASYNC MODE Menu, set the desired ES Interface type:
ES INTERFACE {RS-232, RS-485}
This allows the user to select the interface type.
6. Under TX ASYNC MODE Menu, set the desired baud rate for the ASYNC Port (J17). This will be the baud rate that will pass through the overhead channel:
ES BAUD RATE {150 - 19200}
This allows the user to select the baud rate of the ASYNC port (J17) in SCC Mode.
7. Under TX ASYNC MODE Menu, set the desired ES BITS/CHAR:
ES BITS/CHAR {7,8}
This allows the user to choose between 7 or 8 bits of data.
8. Repeat Steps 4 through 7 under the RX ASYNC MODE (menu)
9. The physical connection to the overhead channel will be the DB-9 Female Port labeled ASYNC (J17).
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3.16 EDMAC Satellite Framing/Deframing Mode
The modem supports EDMAC satellite framing. EDMAC can be enables for both modulator and demodulator satellite framing when modem is configured in CLOSED NET applications. EDMAC satellite framing DOES NOT allow control or monitoring of the remote slave modem. On the demodulator, terrestrial date is framed with NULL EDMAC commands, having no effect at the remote demodulator. On the demodulator, EDMAC commands are stripped from the satellite data stream and discarded, leaving the terrestrial data steam intact. EDMAC Framing/Deframing is provided for compatibility purposes only.
3.17 Locating the ID Code Operational Procedure
The modem has unique ID codes that allow the user to add feature upgrades to the modem without the unit having to be returned to the factory. Users are required to identify these ID codes when they want additional features added to their unit. Comtech will supply a new ID code that is required to be entered in the ID code field. Once the new ID code is entered, the modem will activate the new features.
Refer to Appendix B for upgrade procedures.
3.18 Strap Codes
The Strap Code is a quick set key that sets many of the modem parameters. For quick setup of the modem, Strap Codes are very helpful. When a Strap Code is entered, the modem is automatically configured for the code’s corresponding data rate, overhead, code rate, framing, scrambler type and modulation. An example of how to set a strap code follows:
Example: In the Ethernet interface <Modulator> Menu, depress the Transmit Gel-tab, then move the cursor down and depress “General”. Now move the cursor over to ‘Strap Code’. Click inside the box and enter the new strap code submenu and enter #16. The DMD50 will be automatically configured to the parameters shown below in the highlighted row ‘Strap Code 16’.
Refer to Appendix D or the various strap code options.
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Chapter 4. User Interfaces
4.1 User Interfaces
This section contains information pertaining to the user interfaces for the modem. There are four user intefaces available for the modem. These are:
Front Panel Interface – Refer to Section 4.2.
Terminal Interface - :Refer to Section 4.6.
RS485 Remote Port Interface (RLLP) – Refer to the Sect ion 4.9.
Ethernet Remote Port Interface (SNMP) – R efer to Section 4.10.
Ethernet Remote Port Interface (Web Browser) - Refer to Section 4.10.
4.2 Front Panel User Interface
The Front Panel allows for complete control and monitor of all parameters and functions via a keypad, LCD display and status LEDs.
The front panel layout is shown in Figure 4-1, showing the location and labeling of the front panel. The front panel is divided into four functional areas: the LCD Front Panel Display, the Cursor Control Arrow Keys, the Numeric Keypad, and the Front Panel LED Indicators, each described in Table 4-1.
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Figure 4-1. Front Panel
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DMD50 Universal Satellite Modem User Interfaces
Number
Description
Function
LCD Front Panel Display
Cursor Control Arrow Keys
Controls the up, down, right and left motion of the cursor in the
LCD Display window
3
Numeric Keypad
Allows entry of numeric data and Clear and Enter function keys
Front Panel LED
See Paragraph 4.1.4 below for an itemized description of these
Edit Mode Key Fun ct io ns (Front Panel On ly )
Parameter
‘Clear’ &
‘Clear’ &
Moves
Moves
Moves
Moves
Previous
List
Table 4-1. Front Panel Description
1
Displays operating parameters and Configuration data
2
4
Indicators
LEDs
4.2.1 LCD Front Panel Display
The front panel display is a 2 line by 16-character LCD display. The display is lighted and the brightness can be set to increase when the front panel is currently in use. The LCD display automatically dims after a period of inactivity. The display has two distinct areas showing current information. The upper area shows the current parameter being monitored, such as ‘Frequency’ or ‘Data Rate’. The lower line shows the current value of that parameter. The LCD display is a single entry window into the large matrix of parameters that can be monitored and set from the Front Panel.
4.2.2 Cursor Control Arrow Keys
A set of ‘Arrow’ or ‘Cursor’ keys (↑), (↓), (→), (←), is used to navigate the parameter currently being monitored or controlled. Table 4-2 describes the functions available at the Front Panel.
4.2.3 Numeric Keypad
A 10-Key Numeric Keypad with two additional keys for the ‘Enter’ and ‘Clear’ function allows the entry of data into the system. Table 4-2 describes the functions available at the Front Panel.
Type
Fixed Point
Decimal
Unsigned
Hexadecimal
Enumerated N/A
0 – 9
Changes
Digit
Changes
Digit
Table 4-2. Edit Mode Key Functions
Toggles ±
(If Signed)
Toggles ±
(If Signed)
Cursor 1
Position
Left
Increments
Digit Value
Decrements Digit Value
Cursor 1
Position
Left
Value in
Next Value
in List
N/A N/A N/A N/A
Cursor 1
Position
Right
Cursor 1
Position
Right
N/A N/A
N/A N/A
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DMD50 Universal Satellite Modem User Interfaces
Moves
Left
Moves
Right
Moves
Left
Moves
Right
Moves
Left
Moves
Right
Clears to
Inclusive
Clears to
Inclusive
Date/ Time
IP Address
Text Strings
Changes
Digit
Changes
Digit
Changes
Character
N/A N/A
Increments
Digit Value
Increments
Character
Value
4.2.4 Front Panel LED Indicators
Eight LEDs on the Front Panel (Refer to Table 4-3) indicate the status of operation. The LED colors maintain a consistent meaning. Green signifies that the indication is appropriate for normal operation, Yellow means that there is a condition not proper for normal operation, and Red indicates a fault condition that will result in lost communications.
Table 4-3. LED Color Reference
LED Color Function
Decrements Digit Value
Decrements
Character
Value
Cursor 1
Position
Cursor 1
Position
Cursor 1
Position
Cursor 1
Position
Cursor 1
Position
Cursor 1
Position
N/A N/A
N/A N/A
Left of Cursor
Right of
Cursor
Modem LED Indicators
Power Green Indicates that the unit is turned on.
Fault Red Indicates a hardware fault for the unit.
Event Yellow Indicates that a condition or event has occurred that the
modem has stored in memory. The events may be viewed from the Front Panel or in the Terminal Mode.
Remote Green Indicates that the unit is in the process of updating firmware
with FTP or flashing indicates some features are demo enabled.
Modulator LED Indicators
Transmit On Green Indicates that the transmitter is on.
Major Alarm Red Indicates that the Transmit Direction has failed, losing
traffic.
Minor Alarm Yellow Indicates that a Transmit Warning Condition exists.
Test Mode Yellow Indicates that the transmitter is involved in a current Test
Mode activity.
Demodulator LED Indicators
Signal Lock Green Indicates that the receiver locked to an incoming carrier and
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DMD50 Universal Satellite Modem User Interfaces
Major Alarm Red Indicates that the Receive Direction has failed, losing traffic.
Minor Alarm Yellow Indicates that a Receive Warning Condition exists.
Test Mode Yellow Indicates that the receiver is involved in a current Test Mode
activity.
4.3 Parameter Setup
The four Cursor Control Arrow Keys are used to navigate the menu tree and select the parameter to be set. After arriving at a parameter that needs to be modified, depress <ENTER>. The first space of the modifiable parameter highlights (blinks) and is ready for a new parameter to be entered. After entering the new parameter using the keypad (Refer to Figure 4-2), depress <ENTER> to lock in the new parameter. If a change needs to be made prior to pressing <ENTER>, depress <CLEAR> and the display defaults back to the original parameter. Depress <ENTER> again and re-enter the new parameters followed by <ENTER>.
Figure 4-2. Entering New Parameters
Following a valid input, the unit will place the new setting into the nonvolatile EEPROM making it available immediately and available the next time the unit is powered-up.
4.4 Front Panel Control Screen Menus
The Front Panel Control Screens are broken down into sections under several Main Menus.
4.4.1 Main Menus
• MODULATOR
• DEMODULATOR
• INTERFACE
• MONITOR
• ALARMS
• SYSTEM
• TEST
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DMD50 Universal Satellite Modem User Interfaces
4.4.2 Modulator Menu Options and Parameters
NETWORK SPEC {IDR, IBS, DROP & INSERT, CLOSED NET, DVB SAT}
The Network Spec Command sets a number of parameters
within the modem to meet a specification. The purpose is to eliminate keystrokes and potential compatibility problems.
Data rates not covered by a given network specification will not
be allowed. If the mode of operation is selected after the data rate has been entered, then the data rate must be compatible with the desired mode of operation or the network spec will not be allowed. The following parameters cannot be changed while the unit is in the given mode of operation:
IDR:
(IESS-308)
For Data rates 1.544, 2.048, 6.312, 8.448 Mbps
Framing Type: 96 Kbps (IDR) Scrambler Type: V.35 Spectrum Mask: Intelsat
For Data Rates < 1.544 Framing Type: 1/15 (IBS) Scrambler Type: IESS-309 Spectrum Mask: Intelsat
IBS:
(IESS-309)
For Data Rates < 2048 Framing Type: 1/15 (IBS)
Scrambler Type: IESS-309
Spectrum Mask: Intelsat
Drop & Insert:
Data Rates: n x 64 n = 1, 2, 3, 4, 5, 6, 8, 10,12, 15,
16, 20, 24, 30
Framing Type: 1/15 (I BS)
Scrambler Type: IESS-309 Spectrum Mask: Intelsat
Efficient D&I Closed Network,
Data Rates: n x 64, N = 1-31 Any combination Descrambler Type: IESS-309 Spectrum Mask: Intelsat
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DVB: Per EN301-421 & En301-210
Data Rates: All Rates
Framing Type: DVB Scrambler Type: DVB Spectrum Mask: DVB 0.25, 0.35
Closed Net:
All possible combinations allowed, however, DVB settings
requires the DVB network spec. Activates the AUPC Menu.
STRAP CODE {Refer to Strap Code Guide, Appendix D} The Strap Code is a quick set key that sets many modem
parameters. Consult the strap code guide for available strap codes. Parameters set by strap code:
Data Rate
Inner Code Rate Satellite Framing Scrambler Drop and Insert Outer Code Rate (Reed-Solomon) Modulation Network Spec
IF (menu)
FREQUENCY (MHz) {50 – 90 MHz, 100 – 180 MHz, or 950 - 2050 MHz} Allows the user to enter the Modulator IF Output Frequency of
the modem in 1 Hz increments.
POWER (dBm) {0 to -25 dBm}
Allows the user to enter the Transmitter Power Level.
CARRIER {ON, OFF, AUTO, VSAT, RTS}
Allows the user to select the carrier type. Refer to Appendix E
for further information.
SPECTRUM {NORMAL, INVERTED}
Allows the user to invert the direction of rotation for PSK
Modulation. Normal meets the IESS Specification..
MODULATION {QPSK, BPSK, OQPSK, 8PSK, 16QAM} Allows the user to select the modulation type.
SPECTRAL MASK {Intelsat 0.35, DVB SAT 0.35, DVB SAT 0.25, DVB SAT
0.20}
Allows the user to set the spectral shape of Tx Data Filter.
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COMPENSATION {0.0 – 1.0}
Allows you to offset output power by up to 1 dbm. This is intended as a correction for user cabinet connectors.
DATA (menu) DATA RATE (bps) {Refer to Technical Specs for Data Rates}
Allows the user to set the Data Rate in bps steps via the Front
Panel Arrows or Keypad.
SYMB RATE (sps) Allows the user to view the Symbol Rate.
INNER FEC Viterbi {1/2, 3/4, 7/8, None}
Optional FEC Rates: Sequential {1/2, 3/4, 7/8} Trellis {8PSK} Turbo 20Mbps {.793, .495, 3/4, 7/8} Turbo >20Mbps {.750, .875} CSC {3/4} DVB VIT {2/3, 5/6} DVB Trellis {3/4, 5/6, 7/8, 8/9} LDPC (B/O/QPSK) {1/2, 2/3, 3/4} LDPC (8PSK) {2/3, 3/4} LDPC (8QAM) {2/3, 3/4} LDPC (QPSK/OQPSK) {1/2, 2/3, 3/4} LDPC (16QAM) {3/4} Allows the user to select the Rx Code Rate and Type
TPC INTERLEAVER {DISABLE, ENABLE} Allows user to disable or enable the TPC Interleaver. Valid only
for Radyne turbo codes TPC.495 and TPC.793
DIFF CODING {ENABLED, DISABLE} Allows the user to enable or disable the Differential Encoder.
Having the encoder enabled ensures proper phase lock. May not be adjustable in some modes.
SCRAMBLER SEL {NONE, V.35-IESS, V.35 CITT, V.35 EF, IBS w/Optional
Framing and optional Reed-Solomon, Reed-Solomon Scrambler w/Optional Framing, CCITT, V.35FC, OM-73, V.35EF_RS, TPC SCRAMBLER (Turbo Codec), DVB, EDMAC}
Allows the user to select the descrambler type.
SCRAMBLER CTRL {ENABLED, DISABLE} Allows the user to enable or disable scrambler operation.
SAT FRAMING {1/15 (IBS), 1/15 (Async), 96 Kbps (IDR), DVB, EDMAC,
EFAUPC, SCC, EFFICIENT D&I, None}
Used with IDR, IBS, or Asynchronous Interface Only. Allows the user to select the framing type.
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IN-BAND RATE {150, 300, 600, 1200, 2400, 4800, 9600, 19200} Allows the user to select the rate of in-band data for the ES to
ES, Async overhead channel.
Only displayed when Effiecient D&I with Enhanced Async
are selected.
SCC CTL RATIO {1/1, 1/2, 1/3, 1/4, 1/5, 1/6, 1/7},
Allows th e u se r to simulate the framing used by the Satellite
Control Channel Option (Pass Thru Mode only). The SCC CTL RATIO is the ratio of overhead in-band data to synchronizing words.
Only displayed when SCC Framing is selected SCC INBAND RATE {300 to 200000}, when using SCC Framing
Allows the user to request the rate of in-band data for the
overhead channel.
Only displayed when SCC Framing is selected TERR FRAMING {NONE, 188, 204}, when using DVB Network Specifications
DATA POLARITY {INV. TERR & BASE, INV. BASEBAND, INV.TERR
DATA, NONE}
Allows the user to invert the Tx Data polarity.
SYMBOL PAIR {NONE, SWAPPED} Allows the user to swap the I & Q Channels, when using BPSK
modulation.
ESC OVERHEAD {VOICE X2, DATA 64KBPS} IDR ESC Channel used for Voice or 64 K data channel. Only
available when IDR Network is selected.
AUPC (menu)
LOCAL AUPC (menu) The 'LOCAL AUPC CONFIGURATION' Menu contains the
local configuration parameters for the AUPC Function.
AUPC MODE {DISABLED, NEARSIDE, RADYNE, EFDATA}
DISABLED: Allows the user to enable or disable the Local
AUPC Function of the local modem.
EFDATA: Enables EFDATA Local AUPC Function. In the event that the remote or local demodulator losses lock, the output power level will adjust itself to the lev e l se tt in gs indicated in the 'REMOTE CL ACTION' Menu or the 'LOCAL CL ACTION'.
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RADYNE: Enables Radyne Local AUPC Function. In the event the remote demodulator losses lock, the local output power level will adjust itself to the nominal level. This nominal power should be set to a level high enough to re-establish communications regard less of rain fad e.
NEARSIDE: Enables NEARSIDE Local AUPC function. In the event the local demodulator losses lock due to signal loss, the output power level will adjust itself to the nominal level. This nominal power should be set to a level high enough to re­establish communications r eg ardle ss of rain fad e.
NOMINAL TX POWER {0 TO -25 dB} This allows the user to set the nominal Transmit Power. The
nominal transmit power is the default output power level.
MINIMUM TX POWER {0 to -25 dB} This allows the user to set the minimum Transmit Power.
EFDATA AUPC: When configured for EFDATA AUPC the
minimum Transmit Power is the lowest power setting that will be used when the local modem commands a decrease of the Transmit Power from the Remote modem.
RADYNE: When configured for Radyne AUPC, the minimum
Transmit Power is the lowest power setting that will be used when the remote modem commands a decrease of the Transmit Power from the Local modem.
NEARSIDE: When configured for NEARSIDE AUPC the
minimum Transmit Power is the lowest power setting that will be used by the local modem when the Eb/No increases above the Eb/No target.
MAXIMUM TX POWER {0 to -25 dB} This allows the user to set the maximum Transmit Power.
EF AUPC: When configured for EF AUPC, the maximum
Transmit Power is the highest power setting that the local modem will use when the local modem commands an increase in Transmit power from the Remote modem.
RADYNE: When configured for Radyne AUPC, the maximum
Transmit Power is the highest power setting that will be used when the remote modem commands an increase of the Transmit Power from the Local modem
NEARSIDE: When configured for NEARSIDE AUPC the
maximum Transmit Power is the highest power setting that will be used by the local modem when the Eb/No decreases below the Eb/No target.
TARGET Eb/No {4.0 to 16 dB}
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This allows the user to set the desired Eb/No for the local
receiver.
RADYNE AUPC: When configured for Radyne AUPC, this
setting is compared against the rem ote E
and commands to
b/No
the local modem to increase or decrease the local transmit power.
EF AUPC: When configured for EF AUPC, this setting is
compared against the local received E
and commands to the
b/No
remote modem to increase or decrease transmit power.
NEARSIDE: When configured for NEARSIDE AUPC, this
setting is compared against the receiv ed E
of the local
b/No
modem and commands to the local modem to increase or decrease transmit power.
TRACKING RATE {0.5 to 6.0} Allows the user to set the rate at which the commands to increase
or decrease Transmit Power are sent. Each command will result in a 0.5 dB increase or decrease in Transmit Power from the remote transmitter. The tracking rate is adjustable from 0.5 dB per minute to 6.0 dB per minute in 0.5 dB steps. (Only
available when EFAUPC is selected as the framing )
LOCAL CL ACTION {HOLD, NOMINAL, MAXIMUM} This allows the user to set the Remote Transmit Power Setting to
be used when the local modem receiver loses lock. The setting can be 'HOLD' (no action taken), 'NOMINAL' (the nominal Transmit Power Setting is used), and 'MAXIMUM' (the maximum Transmit Power Setting is used). (Only available
when EFAUPC is selected as the framing)
REMOTE CL ACTION {HOLD, NOMINAL, MAXIMUM} This allows the user to set the Local Transmit Power Setting to
be used when the remote modem receiver loses lock. The setting can be 'HOLD' (no action taken), 'NOMINAL' (the nominal Transmit Power Setting is used), and 'MAXIMUM' (the maximum Transmit Power Setting is used).
REMOTE AUPC (menu) The 'REMOTE AUPC CONFIGURATION' Menu contains the
remote configuration parameters for the AUPC Function. Remote AUPC menus are only available when modem is configured for EF AUPC
AUPC MODE {DISABLE, EFDATA}
Allows the user to enable or disable the AUPC Function of the remote modem. The remote AUPC Function is the response of the local modem to commands for an increase or decrease of the Transmit Power in 0.5 dB steps and the command to change to the setting indicated in the 'REMOTE CL ACTION' Menu of the remote modem upon receiver loss of lock.
LOOPBACK {DISABLE, ENABLE}
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Allows the user to enable or disable the Baseband Loopback Test
Mode of the remote modem.
TX 2047 TEST {DISABLE, ENABLE} Allows the user to enable or disable the Transmit 2047 Pattern
Test Mode of the remote modem.
RX 2047 BER: Reports the BER measurement of the receiver 2047 Pattern Test
Mode of the remote modem. BER is reported from the 1x10
-7
1x10
in tenth decade steps.
-5
to
if the pattern does not synchronize or is out of range, ‘NO
DATA’ will be displayed.
When modems are configured for Radyne AUPC, the remote Eb/No will be displayed in the Monitor Menus.
REED-SOLOMON (menu) These selections are visible only when the Reed-Solomon Option
is installed.
ENABLE/DISABLE {ENABLED, DISABLE} Allows the user to Enable/Disable the Reed-Solomon Encoder.
RS RATE {Refer to Table 3-1 for standard n/k values} Displays the currently used n, k Reed-Solomon Codes. In
Closed Net Mode and using the appropriate hardware, the user may select custom R-S Codes.
INTERLVR DEPTH {4, 8, 12} Allows the user to select the Reed-Solomon interleaver depth. In
Closed Net Mode, a depth of 4 or 8 may be selected.
4.4.3 Demodulator Menu Options and Parameters
NETWORK SPEC {IDR, IBS, DROP & INSERT, CLOSED NET, DVB SAT} The Network Spec Command sets a number of parameters
within the modem to meet a specification. The purpose is to eliminate keystrokes and potential compatibility problems.
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Data rates not covered by a given mode will not be allowed. If
the mode of operation is selected after the da ta rate has been entered, then the data rate must be compatible with the desired mode of operation or the Network Spec will not be allowed. The following parameters cannot be changed while the unit is in the given mode of operation:
IDR:
(IESS-308) For Data rates 1.544, 2.048, 6.312, 8.448 Mbps Framing Type: 96 Kbps (IDR) Descrambler type: V.35 Spectrum Mask: Intelsat
For Data Rates < 1.544 Mbps Framing Type: 1/15 (IBS) Descrambler Type: IESS-309 Spectrum Mask: Intelsat
IBS:
(IESS-309) For Data Rates < 2.048 Mbps Framing Type: 1/15 (IBS) Descrambler Type: IESS-309 Spectrum Mask: Intelsat
Drop & Insert: Data Rates: n x 64, n = 1, 2, 3, 4, 5, 6, 8, 10, 12, 15,
16, 20, 24, 30 Framing Type: 1/15 (IBS) Descrambler Type: IESS-309 Spectrum Mask: Intelsat
Efficient D&I Closed Network,
Data Rates: n x 64, 1-31 Any combination Descrambler Type: IESS-309 Spectrum Mask: Intelsat
DVB: Per EN301-421 & En301-210 Data Rates: All Rates
Framing Type: DVB
Scrambler Type: DVB Spectrum Mask: DVB 0.25, 0.35
Closed Net:
All possible combinations allowed, however, DVB settings requires the DVB network spec.
STRAP CODE {Refer to Strap Code Guide, Appendix D}
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The Strap Code is a quick set key that sets many modem
parameters. Consult the strap code guide for available strap codes. Parameters set by strap code:
Data Rate
Inner Code Rate Satellite Framing Scrambler Drop and Insert Outer Code Rate (Reed-Solomon) Modulation
Network Spec
IF (menu)
FREQUENCY (MHz) {50 – 90 MHz, 100 – 180 MHz, or 950 - 2050 MHz}
Allows the user to enter the Modulator IF Frequency in 1 Hz
increments.
SPECTRUM {NORMAL INVERTED}
Allows the user to invert th e di rec tion of rotation for PSK
Modulation. Normal meets the IESS Specification.
MODULATION {QPSK, BPSK, OQPSK, 8PSK, 16QAM}
Allows the user to select the demodulation type.
SPECTRAL MASK {Intelsat 0.35, DVB 0.35, DVB 0.25, DVB 0.20} Allows the user to set the spectral shape of Tx Data Filter.
SWEEP RANGE (kHz) {±0 to 255 kHz} Allows the user to set the acquisition range for the demodulator
SWEEP DELAY (Sec) {0.0 – 6553.5 sec}
Allows the user to set the reacquisition delay time in 1/10
th
second increments.
REACQ RANGE (Hz) {0 – 65535 Hz}
Allows the user to set the reacquisition sweep in 1 Hz
increments.
ADJ CARRIER PWR {Normal, Supressed} Allows the user to indicate adjacent carrier as Normal or
Supressed (High Power). Unit will increase or decrease post decimination gain appropriately.
FAST ACQUISITION {DISABLED, ENABLED} Allows the user to disable or enable the Rx fast acquisition
capability.
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Does not support spectral inversion applications.
Limitations of Fast Acquistion: The maximum symbol rate for Fast Acquistion is 1028Ksps. Fast Acquistion must be disable for rates greater than 1028Ksps. Only supports QPSK and 8PSK in a NON-DVB MODE.
INPUT THRESHOLD (dBm) {-30 to 90 dbm} Allows the user to adjust the low level threshold limit for input
power. Input power level below the threshold limit will trigger a major alarm on the demodulator.
EB/NO ALARM {0.0 to 9.90 db} Allows the user to set the desired E
This setting is compared against the receive E
for the local receiver.
b/No
and
b/No
commands to the remote modem to increase or decrease Transmit Power accordingly are sent.
DATA (menu)
DATA RATE (bps) {Refer to Technical Specs for Data Rates} Allows the user to set the Data Rate in bps steps via the Front
Panel Arrows or Keypad.
SYMB RATE (sps) Allows the user to view the Symbol Rate. INNER FEC Viterbi {1/2, 3/4, 7/8, None}
Optional FEC Rates: Sequential {1/2, 3/4, 7/8} Trellis {8PSK} Turbo 20Mbps {.793, .495, 3/4, 7/8} Turbo >20Mbps {.750, .875} CSC {3/4} DVB VIT {2/3, 5/6} DVB Trellis {3/4, 5/6, 7/8, 8/9} LDPC (B/O/QPSK) {1/2, 2/3, 3/4} LDPC (8PSK) {2/3, 3/4} LDPC (8QAM) {2/3, 3/4} LDPC (QPSK/OQPSK) {1/2, 2/3, 3/4} LDPC (16QAM) {3/4}
Allows the user to select the Rx Code Rate and Type
TPC INTERLEAVER {DISABLED, ENABLED}
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Allows the user to disable or enable TPC Interleaver. Valid only
for Radyne turbo codes TPC.495 and TPC.793.
DIFF CODING {ENABLED, DISABLE} Allows the user to enable or disable the Differential Decoder.
Having the decoder enabled ensures proper phase lock. May not be adjustable in some modes.
SCRAMBLER SEL {NONE, V.35-IESS, V.35 CITT, V.35 EF, IBS w/Optional
Framing and optional Reed-Solomon, Reed-Solomon Scrambler w/Optional Framing, CCITT, V.35FC, OM-73, V.35EF_RS, TPC SCRAMBLER (Turbo Codec), DVB, EDMAC}
Allows th e u se r to select the descrambler type.
SCRAMBLER CTRL {ON, OFF} Allows the user to enable or disable the descrambler operation.
SAT FRAMING {1/15 (IBS), 1/15 (Async), 96 Kbps (IDR), EDMAC,
EFAUPC, SCC, EFFICIENT D&I, None}
Used with IDR, IBS, or Asynchronous Interface Only. Allows the user to select the Framing Type. IN-BAND RATE {150, 300, 600, 1200, 2400, 4800, 9600, 19200} Allows the user to select the rate of in-band data for the ES to
ES, Async overhead channel. Only displayed when Effiecient
D&I with Esc Enhanced are selected.
SCC CTL RATIO {1/1, 1/2, 1/3, 1/4, 1/5, 1/6, 1/7} Allows the user to simulate the framing used by the Satellite
Control Channel Option (Pass Thru Mode only). The SCC CTL RATIO is the ratio of overhead in-band data to synchronizing words.
Only displayed when SCC Framing is selected. SCC INBAND RATE {300 to 200000},
Allows the user to request the rate of in-band data for the
overhead channel.
Only displayed when SCC Framing is selected. TERR FRAMING {NONE, 188, 204}, when using DVB Network Spec
DATA POLARITY {INV. TERR & BASE, INV. BASEBAND, INV.TERR
DATA, NONE}
Allows the user to invert the Rx Data polarity.
SYMBOL PAIR {NONE, SWAPPED} Allows the user to swap the I & Q Channels, when using BPSK
Modulation.
ESC OVERHEAD {VOICE X2, DATA 64KBPS} IDR ESC Channel used for Voice or 64 K data channel. Only available when IDR Network is selected.
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REED-SOLOMON (menu) These selections are visible only when the Reed-Solomon Option
is installed.
ENABLE/DISABLE {ENABLED, DISABLED} Allows the user to Enable/Disable the Reed-Solomon Encoder.
RS RATE {Refer to Table 3-1 for standard n/k values} Displays the currently used n, k Reed-Solomon Codes. In
Closed Net Mode and using the appropriate hardware, the user may select custom R-S Codes.
INTERLVR DEPTH {4, 8, 12}
Allows the user to select the Reed-Solomon interleaver depth.
CNC (menu) These selections are visible only when the Carrier in Carrier card
is installed.
ENABLE/DISABLE {ENABLED, DISABLED} Allows the user to Enable/Disable the Carrier in Carrier.
MIN SRCH DELAY {Minimum Search Delay (ms), 0 to Max}
MAX SRCH DELAY {Maximum Search Delay (ms), Min to 330ms}
FREQ OFFST RNG {Range of Frequency Offset (KHz) between the Interferer
and the desired received signal. (+/- 1Khz to +/- 32Khz)}
4.4.4 Interface Menu Options and Parameters
TX SETUP (menu)
CIRCUIT ID Allows the user entry of a Tx Circuit Identifier. Circuits can be
given up to an 11 Character alphanumeric identity such as LINK1.
TERR INTERFACE STANDARD INTERFACE
{RS422 SERIAL,RS232 SERIAL, V.35}
OPTIONAL HARDWARE INTERFACES {M2P PARALLEL, DVB PARALLEL, ASI} {HSSI} {ETHERNET 10/100 BASE-T} {G.703: T1 AMI, T1 B8ZS, , E1 BAL, E1 UNBAL, T2 BAL,
T2 UNBAL, E2}
{G.703: T1 AMI, T1 B8ZS, , E1 BAL, E1 UNBAL, T2 BAL,
T2 UNBAL, E2, E3, T3, STS1}
Allows the user to select the Transmit Interface Type.
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