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Satellite Commnication Increasingly Use of Satellite Orbit Position and Frequency

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Satellite Commnication Increasingly Use of Satellite Orbit Position and Frequency SATELLITE 01 COMMUNICATION 03 USEFUL INFORMATION SATELLITE 02 MONITORING 04 SUMMARY 01 SATELLITE COMMNICATION INCREASINGLY USE OF SATELLITE ORBIT POSITION AND FREQUENCY • Burst requirement on satellite broadband Internet • The satellite orbit position and frequency is limited • Over 1700 satellites are placed • Over 40 countries and organizations have their own satellites DEVELOPMENT TREND Higher frequency • From S/C band to Ku/Ka band Larger space station • To carry out applications and experiments in the fields of earth, space application new technology, space technology and space medicine Smaller satellite • Lower cost and shorter development period • To carry out research and experience • To provide Internet service and emergency communication to the world RELATED DEFINITIONS IN RADIO REGULATIONS Space radiocommunication: Any radiocommunication involving the use of one or more space stations or the use of one or more reflecting satellites or other objects in space Satellite link: A radio link between a transmitting earth station and a receiving earth station through one satellite RELATED DEFINITIONS IN RADIO REGULATIONS Space station: A station located on an object which is beyond, is intended to go beyond, or has been beyond, the major portion of the Earth's atmosphere RELATED DEFINITIONS IN RADIO REGULATIONS Earth station: A station located either on the Earth's surface or within the major portion of the Earth's atmosphere and intended for communication: - with one or more space stations; or - with one or more stations of the same kind by means of one or more reflecting satellites or other objects in space ADVANTAGES Large coverage and long distance • Theoretically, 3 GSO satellite could provide satellite communication for the earth ADVANTAGES Broadcasting • From earth station to satellite • From satellite to earth stations ADVANTAGES Complex network structure and safety ADVANTAGES Large capacity • Bandwidth • C band: 800 MHz • Ku band: 2050 MHz • Ka band: 2300 MHz • Space division Multiplexing • Applications • Broadcasting • Inmarsat, Iridium • VSAT DISADVANTAGES Time delay • 500ms – 800ms Rain attenuation • C band: < 2 dB • Ku band: <20 dB The Sun Outage • Twice a year, 10 min The Eclipse • Twice a year, 5- 10 min period SATELLITE FREQUENCY Frequency Frequency range Frequency Frequency range band /MHz band /GHz VHF 30-300 Ku 12.5-18 UHF 300-3000 K 18-26 L 390-1550 Ka 26-40 S 1550-3400 Q 40-46 C 3400-8000 V 46-75 X 8000-12500 W 75-111 SATELLITE SERVICE Fixed-satellite service Broadcasting-satellite service Inter-satellite service Radiodetermination-satellite service Space operation service Radionavigation-satellite service Mobile-satellite service Aeronautical radio navigation-satellite service Land mobile-satellite service Radiolocation-satellite service Maritime mobile-satellite service Meteorological-satellite service Aeronautical mobile-satellite service Earth exploration-satellite service Aeronautical mobile-satellite (R) service Standard frequency and signal-satellite service Aeronautical mobile-satellite (OR) service Amateur-satellite service SATELLITE CLASSIFICATION Function • Scientific satellite • Space physics exploration satellite, Astronomical satellite, Microgravity experimental satellite • SACI, solrad-1, SJ-10 • Technology test satellite • Biosatellite • Applied satellite • Communication satellite: Direct Broadcasting Satellite, • Remote sensing satellite: Meteorological satellites • Navigation satellites: GPS, GLONASS, Galileo, Beidou • Earth resources satellites: SMOS, SMAP, Ocean satellite, Landsat SATELLITE CLASSIFICATION Orbit height Name of satellite Abbr. Orbit Height Low Earth orbit satellite LEO 200-2000 km Medium Earth orbit satellite MEO 2000-35786 km High Earth Orbit satellite HEO >35786 km Highly Elliptical Orbit satellite HEO Perigee: 1000-21000 km Apogee: 39500-50600 km Geostationary orbit satellite GEO 35786 km SATELLITE TRANSPONDER Transparent transponder Receive and amplify the signal in the uplink frequency, then retransmit it in the other frequency (downlink frequency) Processing transponder Receive and demodulate the signal in the uplink frequency, then re-modulate it in the other frequency (downlink frequency) SATELLITE ANTENNA Antenna type Parabolic antenna Array antenna Polarization Linear polarization: vertical or horizontal Circular polarization: right or left SATELLITE BEAM COVERAGE IMPORTANT DEFINITIONS EIRP(Effective Isotropic Radiated Power) The product of the power supplied to the antenna and the antenna gain in a given direction relative to an isotropic antenna (absolute or isotropic gain) Unit: dBW Free space transmission loss dB Lp 20log10 (4 d ) 20log 10 ( ) 32.4 20log 10 ( f ) 20log 10 ( d ) PFD(Power Flex Density) 24 9 10 .2 PFD EIRP Lpp 10log10 ( ) 10log 10 ( BW ) EIRP L 10log 10 ( ) 10log 10 ( BW ) dBW/. m Hz 4 4 f 2 f: radio frequency, MHz; d: transmission distance, km; BW: bandwidth , Hz 02 SATELLITE MONITORING IMPORTANCE OF SATELLITE MONITORING • Duty 1: Evaluation on satellite resource utilization • Carrier and transponder level • Orbit position occupancy, frequency occupancy • Orbit position and frequency assignment (over long-term usage) • Power Flux Density(PFD) compliance • Beam coverage • Duty 2: Detection and resolution of interference • Detection and technical analysis of interfering satellite communication networks • Geolocation of interfering transmitters on the surface of the earth • Determination if the interfering transmitters are mobile or fixed • Duty 3: Identification of unauthorized transmitter • Investigation and compliance verification of emission parameters • Identification of unauthorized or improper emissions • Mitigation of the interference SATELLITE MONITORING OPERATIONS Signal reception Signal measurement Signal identification Signal surveillance and alarming Geolocation of transmitter on earth Ground search and confirmation Documentation and database Monitoring data visualization Statistics and analysis What operations to do 1. Satellite reception Acquirement • Antenna system for both GSO satellite and non-GSO satellite • Signal tracking ability Expected output • Polarization • Azimuth • Elevation What operations to do 2. Satellite measurement Acquirement • Modern receiver to perform real-time, non-real-time (post process) and fixed time period measurements • I/Q data recording Expected output • Center frequency • E.I.R.P • Power • Doppler frequency • C/N0 • PFD • Bandwidth What operations to do 3. Satellite identification Acquirement • Post processing and analysis of the signal external and internal parameters • Broadcasting and TV program decoding Expected output • Modulation parameters • Code rate and symbol rate • Communication protocol type • Modulation type • Multiplex Access • Communication system • Coding type • DVB-CID • Communication network type What operations to do 4. Satellite surveillance and alarming Acquirement • Detect an anomaly or unauthorized transmission • I/Q data recording Expected output • Center frequency • Guard band noise level changes • Bandwidth • Modulation characteristics • E.I.R.P • Fast spectrograms What operations to do 5. Geolocation of transmitters on earth Acquirement • Provide an area where an interfering transmitter is most likely • Whether the interferer is stationary or mobile Expected output • Longitude and latitude of the center point of the area • The major axis, minor axis and angle of the area relative to North • Transmitter is stationary or mobile What operations to do 6. Ground search and confirmation Acquirement • To positively identify and mitigate an interfering • Terrestrial measurements with AOA, TDOA, FDOA, POA, ID-aided or correlative principles Expected output • Longitude and latitude of target transmitter • Operator of the target transmitter What operations to do 7. Documentation and database Acquirement • Record monitoring procedures automatically • Long term trend analysis Expected output • Operation documentation • Spectrogram and monitoring data • Audio and video information • Test environment data • Work log What operations to do 8. Monitoring data visualization Time spectrum view Acquirement • To build understanding of the performance of a satellite system over time Time view Continuous signal • displaying data in different formats Bursted signal Expected output SM.1600-04 • Graphic display of signal data in spatial domain, time domain, frequency domain and modulation domain, i.e. spectrogram, waterfall plot, and constellation diagram • Audio and video display (for previously decoded data) • Geolocation result display • Driving route display of monitoring vehicle What operations to do 9. Statistics and analysis Acquirement • To manage the spectrum usage of satellites and earth stations Expected output • Status of receiving antennas • Geolocation results of transmitters on earth. • Satellite orbit position occupancy and frequency occupancy • The emergence of new signals, including unauthorized signals. • Identification of authorized/improper/unauthorized emissions. Authorized emissions by known uplink earth stations have proper RF parameters and are approved by the administration. • Deployment of unauthorized satellite communication network What systems to build System Functions What systems to build System types Fixed monitoring system Transportable monitoring system Mobile monitoring system Aerial monitoring system Portable monitoring system EVALUATION OF SATELLITE RESOURCE
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