Podcast
Questions and Answers
Why did the ITU grant all countries the right to an orbital slot directly over their territory?
Why did the ITU grant all countries the right to an orbital slot directly over their territory?
What is a necessary requirement for installing and operating an earth station or VSAT?
What is a necessary requirement for installing and operating an earth station or VSAT?
What is the purpose of multiple burns during a GEO satellite launch?
What is the purpose of multiple burns during a GEO satellite launch?
What determines the customization of a satellite's payload?
What determines the customization of a satellite's payload?
Signup and view all the answers
What is the estimated cost of launch services for a GEO telecom satellite?
What is the estimated cost of launch services for a GEO telecom satellite?
Signup and view all the answers
What is the main objective of the ITU's orbital slot registration?
What is the main objective of the ITU's orbital slot registration?
Signup and view all the answers
Why do some satellites cost as much as $500 million?
Why do some satellites cost as much as $500 million?
Signup and view all the answers
What is the primary benefit of using satellites in communication systems?
What is the primary benefit of using satellites in communication systems?
Signup and view all the answers
What type of satellite uses GPS technology to provide a person's exact location on Earth?
What type of satellite uses GPS technology to provide a person's exact location on Earth?
Signup and view all the answers
What is the transmission of signals to the satellite called?
What is the transmission of signals to the satellite called?
Signup and view all the answers
What is the advantage of satellite systems utilizing MEO (medium Earth orbit)?
What is the advantage of satellite systems utilizing MEO (medium Earth orbit)?
Signup and view all the answers
Why are satellites complementary to cable?
Why are satellites complementary to cable?
Signup and view all the answers
What is the transmission of information from the satellite called?
What is the transmission of information from the satellite called?
Signup and view all the answers
What is one of the benefits of using satellites in communication systems?
What is one of the benefits of using satellites in communication systems?
Signup and view all the answers
Study Notes
Satellite Operators
- International Mobile Satellite Organization (IMSO) oversees public satellite safety and security communication services via Inmarsat satellites.
- IMSO provides services for maritime safety within the Global Maritime Distress and Safety System (GMDSS), including distress alerting, search and rescue co-ordinating communications, maritime safety information broadcasts, and general communications.
Satellite Services
- The commercial satellite industry provides various services, including:
- Voice/Video/Data Communications
- Position Location
- Rural Telephony
- News Gathering/Distribution
- Internet Trunking
- Corporate VSAT Networks
- Tele-Medicine
- Distance-Learning
- Mobile Telephony
- Videoconferencing
- Business Television
- Remote Sensing
- Pipeline Monitoring
- Security & Database Access
- Emergency Services
- Direct-To-Consumer services, including Broadband IP, DTH/DBS Television, Digital Audio Radio, Interactive Entertainment & Games, and Video & Data to handhelds
Technology Trends
- Market trends for capacity continue to grow despite fibre deployment.
- There is a potential shortage of capacity in some areas due to heavy cutbacks in launches.
- Bandwidth is increasing on a per-link basis.
- User demands include:
- Smaller terminals
- High throughput
- Enhanced capability
- Constellations
- Responsive space
- Lower costs ($1000 or less)
The Space Segment
- A communications satellite has various components, including:
- Propulsion System
- Telemetry, Attitude Control, and Commanding
- Power System/Thermal System
- Solar Arrays
- Receiver Section
- Transponder
- Transmitter Section
- Rx Antennas
- Tx Antenna
- Satellite capacity typically ranges from 24 to 72 transponders, with each transponder capable of handling up to 155 Mbps.
Satellite Design
- Key aspects of satellite design include:
- Electrical Power
- Station Keeping
- Attitude Control
- Orbital Control
- Thermal Control
- Orbital Control involves keeping the satellite stationary with respect to Earth station antennas.
Satellite Orbits
- The ITU Member States have established a legal regime for orbital slot registration.
- The ITU acknowledged that all countries have an equal right to orbital slots.
- Article II of the Outer Space Treaty forbids sovereignty claims over orbital slots.
- Countries have rights to an orbital slot directly over their territory.
Building and Launching a Telecommunications Satellite
- It takes approximately 3 years to build and launch a GEO telecom satellite.
- Satellite payloads are customized for a given mission.
- Satellites undergo extensive testing, including mechanical, thermal, noise, and RF tests.
- The typical cost of a satellite is 150−150-150−250 million, with some costing up to $500 million.
- Launch services and insurance add additional costs (55−55-55−100 million).
Satellite Link Analysis
- A 2 Mbps link using QPSK-3/4 modulation has a required bandwidth of 1.67 MHz and an efficiency of 1.20 bps/Hz.
- The same link using 8PSK-3/4 modulation has a required bandwidth of 1.11 MHz and an efficiency of 1.80 bps/Hz.
- The same link using 8PSK-7/8 modulation has a required bandwidth of 0.95 MHz and an efficiency of 2.10 bps/Hz.
Modcod Selection
- Modcod selection is constrained by signal to noise ratio (SNR) at reception.
- Higher modulation order requires a higher SNR for demodulation.
- SNR is affected by link conditions, available power, satellite performance, antenna size, and modem capabilities.
Satellite Link Budget Analysis
- A satellite link budget analysis determines the suitable modcod, required bandwidth, and power.
Efficiency
- A good efficiency depends on the specific satellite link analysis.
Satellite Communication Components
- A satellite circuit consists of an antenna that transmits/receives and focuses the signal towards/from the satellite.
- The satellite receives signals, filters them, converts frequencies, and amplifies them for transmission.
Benefits of Satellites
- Adaptable to customer requirements
- Mobility
- Cost advantage
- Not affected by geographical obstructions
- Quick implementation
- Alternate routing or redundancy
- Cost is independent of distance
- Cost-effective for short-term requirements
Types of Satellites
- Communications satellites
- Weather satellites
- Earth observation satellites
- Navigation satellites
- Broadcast satellites
- Scientific satellites
- Military satellites
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Learn about the International Mobile Satellite Organization (IMSO), its role in satellite safety and security, and its services within the Global Maritime Distress and Safety System (GMDSS).