User manual WAVECOM EASYSATSYSTEM SOFTWARE W61 - VERSION 1.1

WAVECOM EasySatSystem Software W61 v1.1 User Manual by WAVECOM ELEKTRONIK AG PUBLISHED BY WAVECOM ELEKTRONIK AG Hammerstrasse 8 CH-8180 Buelach Switzerland Phone Fax Email: Internet: +41-44-872 70 60 +41-44-872 70 66 info@wavecom.ch http://www.wavecom.ch © by WAVECOM ELEKTRONIK AG. All rights reserved. Reproduction in whole or in part in any form is prohibited without written consent of the copyright owner. The publication of information in this document does not imply freedom from patent or other protective rights of WAVECOM ELEKTRONIK AG or others. All brand names in this document are trademarks or registered trademarks of their owners. Specifications are subject to change without further notice Printed: Wednesday, March 26, 2008, 17:04:46 Contents Welcome 1 Introduction ............................................................................................. 1 Professional Version ................................................................................... 1 Training ................................................................................................... 1 Source Code ............................................................................................. 1 Company Profile ........................................................................................ 1 Revisions ................................................................................................. 2 References ............................................................................................... 2 Software 2 Installation ............................................................................................... 2 Setup ...................................................................................................... 3 Operation ................................................................................................. 6 Error Handling .......................................................................................... 7 Source ..................................................................................................... 7 Hardware Recommendations 7 Overview ................................................................................................. 7 General Description of the components ......................................................... 7 Antenna ........................................................................................ 7 Downconverter ............................................................................... 8 PC with W61PC(s) ........................................................................... 8 Proven Components ................................................................................... 8 Antenna ........................................................................................ 8 Downconverter ............................................................................... 8 PC ................................................................................................ 8 Glossary of Terms Index 9 29 WAVECOM EasySatSystem Software W61 v1.1 User Manual Contents v Welcome Congratulations on your purchase of a WAVECOM decoder. The product that you bought incorporates the latest technology in data decoding together with the latest software release available at the time of shipment. Please, check our website http://www.wavecom.ch for software updates. Always check the latest documentation on the installation CD or on our website. We thank you for choosing a WAVECOM decoder and look forward to work with you in the future. This chapter introduces WAVECOM ELEKTRONIK AG, the field of activity of the company, and how you may benefit from the expertise of WAVECOM ELEKTRONIK AG. This document describes the 'EasySatSystem' software of WAVECOM ELEKTRONIK AG; this product is sometimes also called 'SAT-Coordination'. Introduction 'EasySatSystem' controls the satellite-modes running on a system of up to 10 W61PC cards such to prevent that more than one W61PC card monitors the same satellite communications session, identified by a specific satellite-mode (INMARSAT-B, INMARSAT-M, and INMARSAT-mini-M), a service (data, fax, ISDN, etc.), and mobile earth station identification number (termed MES Id in the following). The monitoring system configuration is specified in a text file using a very simple syntax. For logging purposes, statistical data concerning the monitored sessions can be collected. 'EasySatSystem' has 3 kinds of user interfaces: the operational status display of the coordinated cards, i.e., the `EasySatSystem' graphical user interface (GUI); the configuration interface, i.e., the text file EasySATSystem.ini, stored in some predefined directory; the MS-DOS command line with parameters. Professional Version This documentation is only available in the professional version of the WAVECOM decoder software. Professional versions are only available to government bodies. WAVECOM maintains a mailing list of our professional customers. For registration details, see Appendix at the end of this manual. Training Please, note that when required WAVECOM is able to provide training on the WAVECOM XML interface. Training can be ordered to take place at the customer location or at our offices in Switzerland. Source Code Source code is available for professional users. To obtain the Source Code please contact WAVECOM, at www.wavecom.ch. Company Profile WAVECOM EasySatSystem Software W61 v1.1 User Manual Welcome 1 WAVECOM ELEKTRONIK GmbH was founded in 1985 in Hohentengen, Germany, close to the Swiss border. In 1991 the company moved to Switzerland and established itself as WAVECOM ELEKTRONIK AG. Now located in Buelach it is within close vicinity of Zuerich airport. The company has focused on decoding and analysis systems for wireless data transmissions. The wide product range spans from professional, high performance systems to devices for private and amateur radio use. The very high quality standards combined with high system performance are appreciated by all customers worldwide. A global network of authorized sales partners ensures that local assistance and basic level support can be provided in most places. More than 95% of all units sold are exported. The majority of the customers are government agencies, defense organizations and the telecommunication industry. About 40% of the turnover is invested in research and development. The employees at WAVECOM ELEKTRONIK AG are mainly engineers with experience in DSP technology, computer and RF hardware development, software engineering and radio data transmission. Access to external know-how and human resources enlarges the capabilities for realizing projects. Manufacturing is outsourced to specialized companies within Switzerland which can handle today's needs for processing surface mount components and fine-pitch structures. WAVECOM ELEKTRONIK AG does not have any juridical or financial links or connections to other companies or official bodies and is completely owned by its general manager, Mr. Christian Kesselring. Revisions Version 0.1 0.2 Date 16-01-2006 26-01-2006 Author Hgr Hgr Changes Initial draft Corrections after comments from RH Install, Setup, Error handling, Source chapters added; .Ini file description adapted to new format; Corrections after review MO, RH Addition of Command Line parameter /A: Reviewed version, Glossary added optional argument /L changed New directories for config and data, under : documents and settings\All users\documents\ wavecom \easysat\config and ...\data 1.0 1.001 1.002 1.003 1.1.000 13-02-2006 29-03-2006 25-10-2006 03-11-2006 10-03-2008 Hgr Hgr Hgr Hgr Hgr References [1] WAVECOM ELEKTRONIK AG, EasySatSystem Specification, V 0.2 Software Installation During the installation of the product `EasySatSystem' by means of the provided setup program, the directory into which the software shall be installed is specified. Hereafter, this directory is denoted as . The following files can be found in : EasySatSystem.exe (the main and only executable) XMLRCICPP.dll (a required DLL) EasySATSystemUserManual.pdf (this document) 2 Software WAVECOM EasySatSystem Software W61 v1.1 User Manual FileHandler.exe (a program solely needed during the installation of `EasySatSystem') WAVECOM_Decoder.chm, the Helpfile Administrator privileges are required to modify the contents of the directory The Config file is stored in the directory (referred to as ): C:\Documents and Settings\All Users\Documents\WAVECOM \EasySat System\Config. This directory contains the files: EasySatSystem.ini Template-EasySatSystem.ini. By default, after start of EasySATSystem.exe, the program looks in this directory for the required configuration file EasySATSystem.ini. However, a different directory can be specified by setting the environment variable EASYSATSYSTEM_CONFIG_DIR accordingly. The collected data will be stored in the directory (referred to as ): C:\Documents and Settings\All Users\Documents\WAVECOM \EasySatSystem\Data. By default, the directory will be used to store statistical data files (if logging has been enabled; see below). Again, a different directory can be specified by setting the environment variable EASYSATSYSTEM_DATA_DIR accordingly. User privileges are sufficient to modify (i.e., also delete) the subdirectories \Config and \Data as well as their respective contents. In order to have `EasySatSystem' working properly, the 'XML Remote Control Interface' port has to be opened on each personal computer (PC) hosting W61PC cards to be coordinated. This is done as follows: 1. Open 'Control Panel'; 2. Open 'Windows Firewall'; 3. If the 'On' button is set, then clear the 'Don't allow exceptions' checkbox; 4. Select the 'Exceptions' tab; 5. Click on 'Add Port...' and give a name and set the port number to the default value of 33234, or to the value you have specified in the tab `Networking Information' of the W61PC WavecomServerControl GUI; 6. For test purposes, it might also be necessary to open the port for the GUI of W61PC (default value of 33233). Furthermore, on each PC hosting W61PC cards to be coordinated, the respective WavecomService must be running and allow remote connections. In order to allow remote connections to a WavecomService, check the box `Allow Remote Connections' in the tab `Networking Information' of the respective W61PC WavecomServerControl GUI. Setup 'EasySatSystem' can run on any PC under the Microsoft Windows XP or Vista operating system. If cards on more than one PC must be coordinated, then the PCs must be connected via a network. 'EasySatSystem' must be told somehow which PCs with which W61PC cards it must coordinate. This is done with the configuration file EasySATSystem.ini, which, by default, needs to be located in the directory . An alternative location can be specified by means of the environment variable EASYSATSYSTEM_CONFIG_DIR. In the EasySATSystem.ini file, one can also specify the sessions to exclusively be watched by listing the respective MES Ids; if no MES Id is specified, then all sessions will be watched. It is also possible to specify the duration (in seconds) of the automatic level setting (ALS) performed at mode start-up. Only the first valid value specified will be used, if several are given in EasySATSystem.ini. If desired, `EasySatSystem' collects statistical data concerning the monitored sessions. In such a case, when exiting `EasySatSystem', a respective text file is stored in the directory or in the directory specified by the environment variable EASYSATSYSTEM_DATA_DIR if it is set. The name of such a file is `Stat.txt', where denotes the date and time (including seconds) of the log-file creation, which occurs at the end of a monitoring session with `EasySatSystem'. Be aware that such a file may become quite large. To enable statistical logging, a sampling interval (in seconds) greater than 0 has to be specified in EasySATSystem.ini. Only the first valid value specified will be used, if several are given in EasySATSystem.ini. The name of the configuration file must be 'EasySATSystem.ini' (case-insensitive). WAVECOM EasySatSystem Software W61 v1.1 User Manual Software 3 Below, the syntax of the configuration file is specified, for which the following rules apply: Whitespace (blanks, tabs) can be expanded to any length; EOL means end-of-line; * means repetition 0 or more times; Single superscript (e.g., xyz10) means repetition exactly the given number of times; Range superscript (e.g., xyz1-9) means repetition with minimum and maximum bounds; Bold words must appear exactly as shown; | means alternative; Terms in <...> are expanded;

::=

* ::= | | | ::= EOL EOLEOLEOL ::= [card_] running number starting at 1 ::= address = ; ::= char1-30 ::= serialno = ; ::= numchar10 ::= ; ::= sat-b | sat-m | sat-mini-m ::= EOLEOL ::= [watch] ::= mesid = ; ::= numchar1-8 ::= EOLEOL ::= [als] ::= EOLEOL ::= [log] ::= period = ; ::= numchar The starting point for the syntax is . Note: The string can be the PC name, or the dotted IP address of the PC. The local PC of 'EasySatSystem' can also be denoted by 127.0.0.1. A maximum of 10 card-sections can be specified. Each card can run on its own PC, so there can be a maximum of 10 PCs. One PC can have a maximum of 8 cards. The number of MES Id watch-sections is not limited. Following are two examples of valid configuration files. Example 1 shows the configuration file for a system with 4 cards configured for INMARSAT-B, 1 for INMARSAT-M and 5 for INMARSAT-mini-M, residing on 2 different PCs (Niklaus2 and Test-w61pc). All MES Ids shall be considered, no ALS shall be performed, and no statistical data shall be collected. In Example 2, the system to be monitored consists of 3 different PCs and 4 cards: the local one (127.0.0.1) with one card and two remote hosts, 123.45.67.89 with one card and ComputerA with two cards. On all cards INMARSAT-B transmissions with specific MES Ids shall be monitored. Furthermore, ALS shall be performed for a period of 5 minutes (300 seconds), and statistical data shall be collected every 30 seconds. 4 Software WAVECOM EasySatSystem Software W61 v1.1 User Manual Example 1: [card_1] address = serialno= mode = [card_2] address = serialno= mode = [card_3] address = serialno= mode = [card_4] address = serialno= mode = [card_5] address = serialno= mode = [card_6] address = serialno= mode = [card_7] address = serialno= mode = [card_8] address = serialno= mode = [card_9] address = serialno= mode = [card_10] address = serialno= mode = Example 2: [card_1] address = serialno= mode = [card_2] address = serialno= mode = [card_3] address = serialno= mode = [card_4] address = serialno= mode = [watch] mesid = [watch] mesid = [watch] mesid = [watch] mesid = [als] period = [log] period = Niklaus2; 0508002720; sat-b; Niklaus2; 0508001120; sat-b; Test-w61pc; 0508007220; sat-b; Test-w61pc; 0508004620; sat-b; Test-w61pc; 0508005620; sat-m; Test-w61pc; 0508008320; sat-mini-m; Test-w61pc; 0508002120; sat-mini-m; Test-w61pc; 0508010020; sat-mini-m; Test-w61pc; 0508003620; sat-mini-m; Test-w61pc; 0508003920; sat-mini-m; 127.0.0.1; 0508002720; sat-b; ComputerA; 0508001120; sat-b; 123.45.67.89; 0508007220; sat-b; ComputerA; 0508004620; sat-b; 12345; 54321; 67890; 98765; 300; 30; The rules must be followed strictly; if there is an error in the EasySATSystem.ini file, the corresponding card will not be included in the coordination process. WAVECOM EasySatSystem Software W61 v1.1 User Manual Software 5 Operation 'EasySatSystem' must be started by the user. The command to start `EasySatSystem' has the following format: /EasySatSystem [/L:] [/A:] The optional argument /L indicates that statistics data should be collected. The number must be in the range 4..120. This number specifies the sampling interval for the statistics data in seconds; (approximately) every n1 seconds a snapshot of the busy status of each card is taken and written at program termination to the statistics file Stat.txt in or in the directory specified by the environment variable EASYSATSYSTEM_DATA_DIR if it is set. If this argument is not present, or n1 is not in the range 4..120, no statistics data will be collected. A sampling interval specified in the configuration file EasySATSystem.ini has precedence over the value passed as argument on the command line. Absence of both parameters indicates that no statistical data has to be collected. The optional argument /A specifies the duration (in seconds) of the ALS that will be performed on each card. An ALS period specified in the configuration file EasySATSystem.ini has precedence over the value passed as argument on the command line. Absence of both parameters indicates that no ALS has to be done. After starting `EasySatSystem', a new window appears on the display, showing one line of status information for each correctly configured W61PC card, as well as the specified ALS period, sampling interval, and MES Id watch-list. The maximum number of cards is fixed to maxN=10, since the window has space for exactly this number. If less than maxN cards are configured, the remaining lines contain empty fields. For each configured card the following information is shown: Column heading Number SAT Mode Computer Name or IP Address Serial # Op Status meaning This is the global number of the card within the scope of the coordinated cards; range: 1..maxN. The SAT mode configured on this card. Address of the computer of this card; can be the (dotted) IP address or the computer name; maximum length 30 characters. Serial number of this card. Operational status of the card, this can be: 'Not Connected': the PC of this card is not under control of `EasySatSystem'; 'Host Connected' (transient): the PC has answered to `EasySatSystem' and announced all its cards; 'Card Ready' (transient): the card has answered; 'Mode Running': the mode was set on the card; 'Busy Session': the card is monitoring a SAT session. If Op Status is ' Busy Session', this is the forward MES Id of the terminal being in the monitoring session, otherwise this field is empty; If Op Status is ' Busy Session', this is the service being monitored, otherwise this field is empty MESId Service The term `transient' means that this state may last only a very short time, and is therefore possibly not visible for the user. If a configured card is not shown at all, then there must be an error in the respective card's specification in the EasySATSystem.ini file. There is only one button available, named 'Exit'. Pressing this button will terminate the program, as will pressing the 'Close' button in the window frame. Note: At start-up, 'EasySatSystem' does not automatically synchronise with the operational status of the cards, meaning that, if a card is already in a session, this is not shown. Only at the next status change of the card, the `Op Status' field will display the correct status. It can take some time until the program has properly terminated after pressing 'Exit' or 'Close'. The system does not check if more than one instance of 'EasySatSystem' coordinates the same card(s). So make sure to start this program with the same cards configured only once. It is recommended to manually control from time to time the signal level settings at the different cards under the control of `EasySatSystem', also when ALS is enabled. 6 Software WAVECOM EasySatSystem Software W61 v1.1 User Manual Error Handling 'EasySatSystem' tries to connect configured, but not connected cards approximately every 30 seconds. All cards not connected are shown in the `Op Status' field accordingly. Source To obtain a Source Code License please contact WAVECOM ELEKTRONIK AG, at http://www.wavecom.ch. Hardware Recommendations This document describes how the WAVECOM W61PC card with the optional W61SAT SW can be used to implement a simple INMARSAT L-Band Monitoring system. A brief overview of the INMARSAT System is given in the help file of the W61PC. Overview The W61SAT SW allows the monitoring of the L-Band downlink (in the 1550 MHz range, also called forward path) of the INMARSAT System. This link contains the information from the Land Earth Station to the Mobile Earth Stations, MES. outdoor indoor L-Band W61 W61 W61 Antenna W61 W61 W61 Downconverter PCs with W61 cards and W61SAT SW coax signal cable The Monitoring System consists of 3 main components: Antenna, including a low noise amplifier, LNA; Downconverter, L-Band to 70 MHz IF; PC(s) with W61 card(s) and the optional W61SAT SW; the PC requirements: > 1 GHz, 512 MB RAM, 60 GB HD, CD; These components are connected with coax cable. If more than 1 W61 is to be fed with the same signal, a splitter should be used to correctly match the impedance of the W61 70 MHz input (input IF70#4, 50 Ohm). General Description of the components Antenna The antenna system must have a figure of merit G/T > 0 dB/K, this is easy possible with a parabolic dish of at least 2 m diameter and a low noise amplifier with a noise figure of 0.8 dB. The polarization of the L- WAVECOM EasySatSystem Software W61 v1.1 User Manual Hardware Recommendations 7 Band signal is RHCP, so if a parabolic reflector is used, the feed must pick up the LHCP component (mirror effect). There is no tracking of the satellite necessary, the antenna can be of a fixed type, which is installed and aligned to the satellite only once. Downconverter This is a commercial product, converting L-Band to 70 MHz IF with a bandwidth of +/- 20 MHz. PC with W61PC(s) These are commercially available computers, with a Pentium processor running under the Microsoft XP Operating System, with at least 1 PCI slot for the W61 card. CPU clock rate should be > 1 GHz, RAM >= 512 MB, and HD of 60 GB, the W61 SW takes about 40 MB, but the disk is used by the collected data from monitoring. Proven Components A system with the following components has been tested at WAVECOM ELEKTRONIK AG, and can be used. Antenna Loopyagi (low cost solution) A L-Band loopyagi antenna, type 2045LY, from Directive Systems [http://www.directivesystems.com/] together with a low-noise amplifier, MKU 152 A, from Kuhne electronic [http://www.kuhne-electronic.de/] allows monitoring the local spot beams with reasonable success. The L-Band signal is connected to the receiver directly. Dish antenna WAVECOM ELEKTRONIK AG uses a 3.7 m epoxy-glass resin dish reflector, with an integrated Feed-LNA from Köditz Nachrichtentechnik [http://www.koeditz-nachrichtentechnik.de/]. The L-Band signal goes directly to the converter. WAVECOM also tested a dish of only 0.7 m diameter with a LNA/feed from SSB electronics (http://www.ssb.de/ but not available any longer) with very useful results. The INMARSAT mini M system is based on spot beams for coverage. This allows to build terminals with a small antenna, but for monitoring, it is impossible to receive all spot beams at a given geographic location. In order to catch also the signals from a neighboring spot beam, the antenna must have more gain, which means a bigger dish than necessary for the local spot beam. WAVECOM recommends a dish of at least 2.4 m diameter. Downconverter At WAVECOM a type MP-9201 Satellite Downconverter from Micro Phase Communications, Inc is used (http://www.microphaseinc.com). PC A Dell computer of the type Dimension 8200 is in use at WAVECOM ELEKTRONIK AG. 8 Hardware Recommendations WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms ADC Analog-to-Digital Conversion. Process of converting analog signals to a digital representation. DAC represents the reverse translation. AFC Automatic Frequency Control. A circuit which automatically controls the frequency of a signal. AGC Automatic Gain Control. A circuit which automatically controls the gain of an amplifier so that the output signal level is virtually constant for varying input signal levels. ALC Automatic Level Control. A circuit which automatically controls the gain of a receiver so that the output signal level is virtually constant. ALS Automatic Level Setting. The process of ALC. AM Amplitude Modulation. The baseband signal is caused to vary the amplitude or height of the carrier wave to create the desired information content. Amplifier A device used to boost the strength of an electronic signal. Antenna A device for transmitting and receiving radio waves. Depending on their use and operating frequency, antennas can take the form of a single piece of wire, a dipole a grid such as a Yagi array, a horn, a helix, a sophisticated parabolic-shaped dish, or a phase array of active electronic elements of virtually any flat or convoluted surface. AOS Acquisition of Signal. The time or location where a satellite is in line of sight. Aperture The cross sectional area of the antenna exposed to the satellite signal. WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 9 Apogee The point in an satellite orbit where the satellite is the highest (farthest distance) from the surface of the earth. Usually measured from the center of the earth. APRS Automatic Position Reporting System. A system developed by Bob Bruninga, WB4APR, for tracking and digital communications with mobile GPS equipped stations with two-way radio. Asymmetric transmission Where the information or data transmission speeds for the forward and return channels differ (e.g. high speed for the forward channel and low for return). Asynchronous transmission A method of data transmission which allows characters to be sent at irregular intervals by preceding each character with a start bit, and following it with a stop bit. Attenuation The loss in power of electromagnetic signals between transmission and reception points. Availability The ratio, expressed as a percentage, of the total time a functional unit or service is capable of being used or is available to be used during a given interval to the length of the interval; e.g., if the unit is not capable of being used for 20 minutes in a week, the availability is 99.8 percent (10080 - 20 minutes/10080 minutes * 100). AZ/EL Mount Antenna mount that requires two separate adjustments to move from one satellite to another. Azimuth Angle between true north and a particular satellite. Can be measured with a compass. Backoff The process of reducing the input and output power levels of a traveling wave tube to obtain more linear operation. Band Pass Filter An active or passive circuit which allows signals within the desired frequency band to pass through but impedes signals outside this pass band from getting through. Bandwidth A measure of spectrum (frequency) use or capacity. For instance, a voice transmission by telephone requires a bandwidth of about 3000 cycles per second (3KHz). A TV channel occupies a bandwidth of 6 million cycles per second (6 MHz) in terrestrial systems. In satellite based systems a larger bandwidth of 17.5 to 72 MHz is used to spread or "dither" the television signal in order to prevent interference. Baseband The basic direct output signal in an intermediate frequency based obtained directly from a television camera, satellite television receiver, or video tape recorder. Baseband signals can be viewed only on studio 10 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual monitors. To display the baseband signal on a conventional television set a "modulator" is required to convert the baseband signal to one of the VHF or UHF television channels which the television set can be tuned to receive. Baud The rate of data transmission based on the number of signal elements or symbols transmitted per second. Today most digital signals are characterized in bits per second. Beacon Low-power carrier transmitted by a satellite which supplies the controlling engineers on the ground with a means of monitoring telemetry data, tracking the satellite, or conducting propagation experiments. This tracking beacon is usually a horn or omni antenna. Beam width The angle or conical shape of the beam the antenna projects. Large antennas have narrower beam widths and can pinpoint satellites in space or dense traffic areas on the earth more precisely. Tighter beam widths thus deliver higher levels of power and thus greater communications performance. Bent Pipe Transponder A "bent pipe" transponder is the term for a transponder that amplifies the received signal and retransmits it to earth without demodulation. It may be a linear transponder, like FO-29, INMARSAT A,B, C, M, that will handle multiple signals as long as they are near the same signal level at the satellite or a limiting transponder that is captured by the strongest signal. Limiting transponders have higher power efficiency than linear transponders. Bird Slang for a communications satellite located in geosynchronous orbit. Bit A single digital unit of information. Bit Error Rate The fraction of a sequence of message bits that are in error. A bit error rate of 10e-6 means that there is an average of one error per million bits. Bit Rate The speed of a digital transmission, measured in bits per second. Byte Sequence or group of eight bits. 1 byte = 8 bits; 1 Kbyte = 1,024 bytes; 1Mbyte = 1,024 Kbytes; 1Gbyte = 1,024 Mbytes. Block Down Converter A device used to convert signals in the frequency range above 1 GHz down to UHF or lower frequencies (1 GHz and lower). BPSK Binary Phase Shift Keying. A digital modulation scheme used in transmission communications. WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 11 Broad beam A single large circular beam that covers a large geographic area, sometimes also called Global beam. Broadcast The sending of one transmission to multiple users in a defined group (compare to unicast). Byte A sequence of eight adjacent binary digits usually treated as a unit. C/N Carrier to Noise Ratio. The ratio of the received carrier power and the noise power in a given bandwidth, expressed in dB. This figure is directly related to G/T and S/N; and in a video signal the higher the C/N, the better the received picture. C/T Carrier-to-noise-temperature ratio. Call 1. Any demand to set up a connection. 2. A unit of traffic measurement. Carrier The basic radio, television, or telephony center of frequency transmit signal. The carrier in an analog signal. is modulated by manipulating its amplitude (making it louder or softer) or its frequency (shifting it up or down) in relation to the incoming signal. Satellite carriers operating in the analog mode are usually frequency modulated. Carrier Frequency The main frequency on which a voice, data, or video signal is sent. Microwave and satellite communications transmitters operate above 1 GHz (a GHz is one billion cycles per second). C-Band This is the band between 4 and 8 GHz. CDMA Code division multiple access. Refers to a multiple-access scheme where stations use spread-spectrum modulations and orthogonal codes to avoid interfering with one another. Channel A frequency band in which a specific broadcast signal is transmitted. Channel frequencies are specified in the United States by the Federal Communications Commission. Analog Television signals require a 6 MHz frequency band to carry all the necessary picture detail. Circuit mode A circuit switched operational mode for transferring (transporting and switching) user information through a network. Contrast with packet switching mode. 12 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual Clarke Belt The name given in honor of Arthur C. Clarke to the orbit 22,237 miles directly above the equator where satellites can maintain a stationary position in relation to the earth. Also called geo-stationary orbit. This orbit was first postulated by the science fiction writer Arthur C. Clarke in Wireless World magazine in 1945. Satellites placed in these orbits, although traveling around the earth at thousands of miles an hour, appear to be stationary when viewed from a point on the earth, since the earth is rotating upon its axis at the same angular rate that the satellite is traveling around the earth. Cliff effect Sudden breakdown or loss of digital signal reception when it contains more errors than the error correction system can cope with. Up to this point there is no degradation in reception quality; a significant advantage over analog where there is a gradual deterioration. Codec 1. Coder/decoder system for digital television transmission. 2. The algorithm (HW or SW) for compressing digital voice. Co-Location Ability of multiple satellites to share the same approximate geostationary orbital assignment frequently due to the fact that different frequency bands are used. Compression A technique to reduce the amount of data to be transmitted that reduces the amount of bandwidth needed to transmit data, video or audio, thus increasing the capacity of a satellite transponder. Data Representation of facts, concepts, or instructions in a formalized manner suitable for communication, interpretation, or processing by humans or by automatic means. dB Decibel. An analog unit of measure of signal strength, volume, or signal loss due to resistance as expressed in logarithmic form. dBi The dB power relative to an isotropic source. DBS Direct broadcast satellite (for television). Refers to service that uses satellites to broadcast multiple channels of television programming directly to home mounted small-dish antennas. dBW The ratio of the power to one Watt expressed in decibels. Delay The time it takes for a signal to go from the sending station through the satellite to the receiving station. This transmission delay for a single hop satellite connection is very close on one-quarter of a second. WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 13 Demodulation The process for retrieving an information signal that has been modulated onto a carrier. Demodulator A unit which extracts or "demodulates" the "wanted "signals from the received carrier. DES Data Encryption Standard. A cryptographic algorithm for the protection of unclassified computer data, issued as Federal Information Processing Standard Publication 46-1. Deviation The modulation level of an FM signal determined by the amount of frequency shift from the frequency of the main carrier. Digital Conversion of information into bits of data for transmission through wire, fiber optic cable, satellite, or over air techniques. Method allows simultaneous transmission of voice, data or video. Digital data Data represented by discrete values or conditions (i.e., "0" or "1"), as opposed to analog data. Digital voice Analog voice signals that have been converted into digital signals. Digitize To convert analog signals into digital ones. Dish A parabolic antenna which collects and focuses satellite signals. C-Band antennas range in size from five to eight feet in diameter, and K-Band antennas range from 18 inches to five feet. Downlink The satellite to earth half of a 2 way telecommunications satellite link. Often used to describe the receive dish end of the link. DSP 1. Digital Speech Processing. 2. Digital Signal Processing. Duplex Transmission Capability for simultaneous data transmission between a sending station and a receiving station. DVB Digital Video Broadcasting. The European-backed project to harmonize adoption of digital video. 14 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual E1 Wide-area digital transmission facility used predominantly in Europe that carries data at a rate of 2.048 Mbit/s. E3 Wide-area digital transmission facility used predominantly in Europe that carries data at a rate of 34.368 Mbit/s. Earth Station The term used to describe the combination or antenna, low-noise amplifier (LNA), down-converter, and receiver electronics. used to receive a signal transmitted by a satellite. Earth Station antennas vary in size from the.2 foot to 12 foot (65 centimeters to 3.7 meters) diameter size used for TV reception to as large as 100 feet (30 meters) in diameter sometimes used for international communications. The typical antenna used for INTELSAT communication is today 13 to 18 meters or 40 to 60 feet. Echo Canceller An electronic circuit which attenuates or eliminates the echo effect on satellite telephony links. Echo cancellers are largely replacing obsolete echo suppressors. Edge of Coverage Limit of a satellite's defined service area. In many cases, the EOC is defined as being 3 dB down from the signal level at beam center. However, reception may still be possible beyond the -3dB point. EIRP Effective Isotropic Radiated Power. This term describes the strength of the signal leaving the satellite antenna or the transmitting earth station antenna, and is used in determining the C/N and S/N. The transmit power value in units of dBW is expressed by the product of the transponder output power and the gain of the satellite transmit antenna. Elevation Angle between the earth's surface and a particular satellite at a given reception point (0° for horizontal and 90° for vertical). Encrypt To convert plain text into an unintelligible form by means of a cryptosystem. EOL End of Life of a satellite. Equatorial Orbit An orbit with a plane parallel to the earth's equator. F/D Ratio of antenna focal length to antenna diameter. A higher ratio means a shallower dish. FDMA Frequency Division Multiple Access. Refers to the use of multiple carriers within the same transponder where each uplink has been assigned frequency slot and bandwidth. This is usually employed in conjunction with Frequency Modulation. WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 15 FEC Forward Error Correction. A technique for improving the robustness of data transmission. Excess bits are included in the outgoing data stream so that error-correction algorithms can be applied upon reception. For the satellite standard the Viterbi code combined with the Reed Solomon code is used. Commercial use of transponders makes 3/4 and 5/6, which means that three out of four or five out of six bits contain useable information. Feed This term has at least two key meanings within the field of satellite communications. It is used to describe the transmission of video programming from a distribution center. It is also used to describe the feed system of an antenna. The feed system may consist of a sub reflector plus a feed horn or a feed horn only Feed horn The part of the satellite system that collects and focuses satellite signals reflected by the dish. FM Frequency Modulation. Focal Length Distance from the center feed to the center of the dish. Focal Point The area toward which the primary reflector (dish) reflects received signal energy. This is where the feed system is typically located. Footprint A map of the signal strength showing the EIRP contours of equal signal strengths as they cover the earth's surface. Different satellite transponders on the same satellite will often have different footprints of the signal strength. The accuracy of EIRP footprints or contour data can improve with the operational age of the satellite. The actual EIRP levels of the satellite, however, tends to decrease slowly as the spacecraft ages. Forward path The transmission path issued from the service provider and reaching the end user. FPGA Field-Programmable Gate Array. This is an array of logic elements that are interconnected via an array of busses Frequency The number of times that an alternating current goes through its complete cycle in one second of time. One cycle per second is also referred to as one hertz; 1000 cycles per second, one kilohertz; 1,000,000 cycles per second, one megahertz: and 1,000,000,000 cycles per second, one gigahertz. Frequency Coordination A process to eliminate frequency interference between different satellite systems or between terrestrial microwave systems and satellites. In the U.S. this activity relies upon a computerized service utilizing an extensive database to analyze potential microwave interference problems that arise between organizations using the same microwave band. As the same C-band frequency spectrum is used by telephone networks 16 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual and CATV companies when they are contemplating the installation of an earth station, they will often obtain a frequency coordination study to determine if any problems will exist. FTP File Transfer Protocol. The Internet protocol (and program) used to transfer files between hosts. Full-duplex operation A mode of operation in which simultaneous communication in both directions may occur between two terminals. In contrast to half duplex or simplex operation in which communications occur in only one direction at a time. G/T A figure of merit of an antenna and low noise amplifier combination expressed in dB. "G" is the net gain of the system and "T" is the noise temperature of the system. The higher the number, the better the system. Gain A measure of amplification expressed in dB. GAN Global Area Network (INMARSAT M-4). Gateway In a communication network, one of the network nodes equipped for interfacing with a network using different protocols. Note: A gateway may contain devices such as protocol translators, impedance matching devices, rate converters, fault isolation, or signal translators as necessary to provide system interoperability. Geostationary Refers to a geosynchronous satellite angle with zero inclination, so the satellite appears to hover over one spot on the earth's equator. Geosynchronous Orbit (GSO) Satellite in geosynchronous orbit travel around the Earth in an area approximately 22,300 miles from the surface at the same rate that the Earth turns, therefore completing one revolution every 24 hours. GHz One billion cycles per second. Signals operating above 3 Gigahertz are known as microwaves, above 30 GHz they are known as millimeter waves. As one moves above the millimeter waves, signals begin to take on the characteristics of light-waves. Global Beam An antenna down-link pattern, which effectively covers one-third of the globe. Global beams are aimed at the center of the Atlantic, Pacific and Indian Oceans by the respective Intelsat satellites, enabling all nations on each side of the ocean to receive the signal. Because they transmit to such a wide area, global beam transponders have significantly lower EIRP outputs at the surface of the Earth as compared to a spotbeam. Therefore, earth stations receiving global beam signals need antennas much larger in size (typically 10 meters and above (i.e., 30 feet and up). WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 17 GMDSS Global Maritime Distress and Safety System. GPS Global Positioning System. Half-duplex operation That mode of operation in which communication between two terminals occurs in either direction but in only one direction at a time. Contrast with duplex or simplex operation. Note: Half-duplex operation may occur on half-duplex circuits or on duplex circuits, but it may not occur on simplex circuits. HGS Hughes Global Services, Inc. High Power Amplifier (HPA) Equipment used to amplify signals. Hub The master station through which all communications to, from and between micro terminals must flow. In the future satellites with on-board processing will allow hubs to be eliminated as MESH networks are able to connect all points in a network together. Hybrid satellite A satellite which carries two or more different communications payloads (i.e., C-band and Ku-band). Hz Hertz. The name given to the basic measure of radio frequency characteristics. An electromagnetic wave completes a full oscillation from its positive to its negative pole and back again in what is known as a cycle. A single Hertz is thus equal to one cycle per second. IBS INTELSAT Business Services. Inclination The angle between the orbital plane of a satellite and the equatorial plane of the earth. INMARSAT The International Maritime Satellite Organization operates a network of satellites for international transmissions for all types of international mobile services including maritime, aeronautical, and land mobile. Established in 1979 to serve the maritime industry by developing satellite communications for ship management and distress and safety applications, INMARSAT currently operates a global satellite system which is used by independent service providers to offer an unparalleled range of voice and multimedia communications for customers on the move or in remote locations. INMARSAT-A: INMARSAT original phone, fax and data system INMARSAT-B: Digital successor to INMARSAT-A INMARSAT-B HSD: 64 Kbit/s high speed data option INMARSAT-C: Store-and-forward data through briefcase terminals 18 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual INMARSAT-D, D+: Global messaging and data broadcasts to pager-sized terminals INMARSAT-E: Global alerting services via INMARSAT INMARSAT-mini-M: INMARSAT smallest satellite phones for voice, fax and data INMARSAT Aero-I: INMARSAT latest aeronautical satcoms service Interference Energy which tends to interfere with the reception of the desired signals, such as fading from airline flights, RF interference from adjacent channels, or ghosting from reflecting objects such as mountains and buildings. Intermodulation No amplifier is perfectly linear, so multiple signals will be combined with each signal unintentionally modulating others in the pass band to some extent. The amount of distortion increases with the signal power levels. The third order intercept is most important for linear transponders and the power level of the thirdorder distortion products increases at three times the rate at which the original signal levels increase. Internetworking The process of interconnecting a number of individual networks to provide a path from a terminal or a host on one network to a terminal or a host on another network. The networks involved may be of the same type, or they may be of different types. However, each network is distinct, with its own addresses, internal protocols, access methods, and administration. IRIDIUM A LEO based satellite voice, messaging and paging system. ISDN Integrated Services Digital Network. A CCITT standard for integrated transmission of voice, video and data. Bandwidths include: Basic Rate Interface - BR (144 Kbps - 2 B & 1 D channel) and Primary Rate - PRI (1.544 and 2.048 Mbps). Isotropic Antenna A hypothetical omni-directional point-source antenna that serves as an engineering reference for the measurement of antenna gain. ITU International Telecommunication Union. Jammer An active electronic counter-measures (ECM) device designed to deny intelligence to unfriendly detectors or to disrupt communications. JPEG ISO Joint Picture Expert Group standard for the compression of still pictures. Ka-Band The frequency range from 18 to 31 GHz. kbps Kilobit per second. WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 19 Refers to transmission speed of 1,000 bits per second. Kelvin (K) The temperature measurement scale used in the scientific community. Zero K represents absolute zero, and corresponds to minus 459 degrees Fahrenheit or minus 273 Celsius. Thermal noise characteristics of LNA are measured in Kelvin. kHz Kilohertz. Refers to a unit of frequency equal to 1,000 Hertz. Ku-Band The frequency range from 10.9 to 17 GHz. This band has been split into two segments by the Federal Communications Commission. The first is the 11.7-12.2 GHz band known as FSS (Fixed Satellite Service), and there are 22 FSS Ku-Band satellites in orbit over North America today. They range in power from 20 to 60 watts per transponder, requiring a three to five foot antenna for clear reception. The 12.2-12.7 GHz segment is known as BSS (Broadcasting Satellite Service). Satellites in this band range in power from 100-200 watts per transponder, allowing the use of receiver antennas as small as 18 inches. LAN Local Area Network. A data communications system that (a) lies within a limited spatial area, (b) has a specific user group, (c) has a specific topology, and (d) is not a public switched telecommunications network, but may be connected to one. L-Band The frequency range from 0.5 to 1.5 GHz. Also used to refer to the 950 to 1450MHz used for mobile communications. Leased Line A dedicated circuit typically supplied by the telephone company. LEO Low Earth Orbit. Satellites placed in orbit less than 22,300 miles above the earth. Line amplifier Amplifier used in the middle of a network to re-amplify a signal. Link Margin The amount of signal in dB by which the satellite system exceeds the minimum levels required for operation. This is usually determined by adding transmitter power and antenna gain, minus the path and transmission line losses. LNA Low Noise Amplifier. A preamplifier usually mounted on a receiving dish antenna designed amplify weak signals and contribute the least amount of thermal noise to the received signal. 20 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual LNB Low Noise Block converter. A small device mounted at the focal point of a satellite dish which converts and amplifies high-frequency satellite signals into lower frequencies. The successor to the LNA. LOS 1. Loss of Signal. The time or point when a satellite passes from being in line of sight of a ground station. 2. Line of Sight. If no obstruction (mountain, building,...) exists between the transmitter and receiver antenna. Margin The amount of signal in dB by which the satellite system exceeds the minimum levels required for operation. Megahertz (MHz) Refers to a frequency equal to one million Hertz, or cycles per second. MEO Medium Earth Orbit. Microwave Line-of-sight, point-to-point transmission of signals at high frequency. Many CATV systems receive some television signals from a distant antenna location with the antenna and the system connected by microwave relay. Microwaves are also used for data, voice, and indeed all types of information transmission. The growth of fiber optic networks have tended to curtail the growth and use of microwave relays. Microwave Interference Interference which occurs when an earth station aimed at a distant satellite picks up a second, often stronger signal, from a local telephone terrestrial microwave relay transmitter. Microwave interference can also be produced by nearby radar transmitters as well as the sun itself. Relocating the antenna by only several feet will often completely eliminate the microwave interference. Modem Acronym for MOdulator-DEModulator. A device that modulates and demodulates signals. Note: Modems are primarily used for converting digital signals into quasi-analog signals for transmission over analog communication channels and for reconverting the quasi-analog signals into digital signals. Modulation The process of manipulating the frequency or amplitude of a carrier in relation to an incoming video, voice or data signal. Modulator A device which modulates a carrier. MPEG The Moving Pictures Experts Group, the television industry's informal standards group. WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 21 MPEG-2 The agreed standard covering the compression of data (coding and encoding) for digital television. MSS Mobile Satellite Service. Multicast Multicast is a subset of broadcast that extends the broadcast concept of one to many by allowing "the sending of one transmission to many users in a defined group, but not necessarily to all users in that group." Multiplexing Techniques that allow a number of simultaneous transmissions over a single circuit. Noise Any unwanted and unmodulated energy that is always present to some extent within any signal. Noise Figure A term which is a figure of merit of a device, such as an LNA or receiver, expressed in dB, which compares the device with a perfect device. On-line Electronic availability on demand from a computer-based system without mounting removable media such as magnetic tape or disks. Outage A telecommunication service condition wherein a user is deprived of service due to a malfunction of the communication system. Packet In data communication, a grouping of a sequence of binary digits, including data and control signals, that is transmitted and switched as a composite whole. The data, control signals, and possibly error control information, are arranged in a specific format. The packet can be of either fixed or variable length. Packet Data A process where stored data is transmitted in discrete units, called packets, allowing for more efficient use of channel capacity and reliability of transfer. Packet mode A packet switched operational mode for transferring (transporting and switching) user information through a network without establishing a connection. The packets do not necessarily arrive at their destination in the order they were sent, unlike the circuit mode of transmission. See packet switching. Packet Switching Data transmission method that divides messages into standard-sized packets for greater efficiency of routing and transport through a network. 22 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual Parabolic Antenna A type of antenna which takes its name from the shape of the dish described mathematically as a parabola. The function of the parabolic shape is to focus the weak microwave signal hitting the surface of the dish into a single focal point in front of the dish. It is at this point that the feed horn is usually located. Pass band The frequency range over which the amplifier or transponder reproduces signals. PCM Pulse Code Modulation. A time division modulation technique in which analog signals are sampled and quantized at periodic intervals into digital signals. The values observed are typically represented by a coded arrangement of 8 bits of which one may be for parity. PCS Personal Communications System. PLL Phase-Locked Loop. A type of electronic circuit used to demodulate satellite signals. Polar Mount Antenna mechanism permitting steering in both elevation and azimuth through rotation about a single axis. While an astronomer's polar mount has its axis parallel to that of the earth, satellite earth stations utilize a modified polar mount geometry that incorporates a declination offset. Polar Orbit An orbit with its plane aligned in parallel with the polar axis of the earth. Polarization A technique used by the satellite designer to increase the capacity of the satellite transmission channels by reusing the satellite transponder frequencies. In linear cross polarization schemes, half of the transponders beam their signals to earth in a vertically polarized mode; the other half horizontally polarize their down links. Although the two sets of frequencies overlap, they are 90 degree out of phase, and will not interfere with each other. To successfully receive and decode these signals on earth, the earth station must be outfitted with a properly polarized feed horn to select the vertically or horizontally polarized signals as desired. In some installations, the feed horn has the capability of receiving the vertical and horizontal transponder signals simultaneously, and routing them into separate LNAs for delivery to two or more satellite television receivers. Unlike most domestic satellites, the Intelsat series use a technique known as left-hand and right-hand circular polarization. Polarization offset angle The angle from vertical that the LNB needs to be set at for maximum reception efficiency. The actual angle depends on the geographical location of the reception site. Polarization Rotator A device that can be manually or automatically adjusted to select one of two orthogonal polarizations. WAVECOM EasySatSystem Software W61 v1.1 User Manual Glossary of Terms 23 Protocol Any set of standard procedures that permit devices to intercommunicate. PSK Phase Shift Keying. A modulation technique that involves phase shifting the carrier to reflect a digital stream. PSTN Public Switched Telephone Network. Any common carrier network that provides circuit switching among public users. Note: The term is usually applied to the public switched telephone network, but it could be applied more generally to other switched networks, e.g., packet switched public data networks. PTT Post Telephone and Telegraph Administration. Refers to operating agencies directly or indirectly controlled by governments in charge of telecommunications services in most countries of the world. Pulse Code Modulation A time division modulation technique in which analog signals are sampled and quantized at periodic intervals into digital signals. The values observed are typically represented by a coded arrangement of 8 bits of which one may be for parity. QPSK Quadrature Phase Shift Keying. System of modulating a satellite signal. Rain Outage Loss of signal at Ku- or Ka-Band frequencies due to absorption and increased sky-noise temperature caused by heavy rainfall. Receiver (Rx) An electronic device which enables a particular satellite signal to be separated from all others being received by an earth station, and converts the signal format into a format for video, voice or data. Receiver Sensitivity Expressed in dBm this tells how much power the detector must receive to achieve a specific baseband performance, such as a specified bit error rate or signal to noise ratio. RFI Radio Frequency Interference. A term used to denote apparent disturbance or distortion to satellite signals. Router Network layer device that determines the optimal path along which network traffic should be forwarded. Routers forward packets from one network to another based on network layer information. 24 Glossary of Terms WAVECOM EasySatSystem Software W61 v1.1 User Manual S/N