Satellite communication systems
Satellite is used for long range wireless communication where there is no other communication infrastructure available. Satellite communication is commonly used off-shore for ship to land communication, or at remote areas like deserts and mountain areas.
Example on satellite communication from boat
Satellite communication is normally more expensive, and consume more energy than ISM radio and GSM/GPRS. However, if the system is well designed and the communication can be limited to once every 2 hours, it is feasible to run the satellite node on solar panel energy.
4 different satellite networks in operation:
- Inmarsat
- Iridium
- Globalstar
- Orbcomm
Inmarsat
nmarsat operates a satellite network for mobile satellite communications services - covering maritime, land mobile, vehicle and aeronautical services. 85% of the worlds land mass is covered by the Inmarsat satellite network -practically every part of the world, except the poles.
Inmarsat came into being as an IGO in 1979 to provide global safety and other communications for the maritime community. It now supports links for phone, fax and data communications to more than 287,000 ship, vehicle, aircraft and other mobile users. For more information, see www.inmarsat.com
Inmarsat fleet coverage (source: www.inmarsat.com)
Iridium
Irridium is a satellite-based, wireless personal communications network providing global satellite voice and data solutions with complete coverage of the earth (including oceans, airways and Polar Regions). The technology is based on 72 satellites as well as 12 fixed ground stations. 66 low-earth orbiting (LEO) satellites are used for telecommunication and 6 satellites are reserved to be moved to positions where needed. For more information, see www.iridium.com
Globalstar
Globalstar is a satellite system offering voice and data service to 120 countries worldwide. The system consists of 48 LEO satellites at an altitude of 780 km. For more information, see www.globalstar.com
Globalstar coverage (source: www.globalstar.com)
Orbcomm
Orbcomm is a global satellite data communication company focused exclusively on Machine-to-Machine (M2M) communications. Orbcomm provides two-way data communications services around the world through a global network of 30 low-earth orbit (LEO) satellites and accompanying ground infrastructure. The system can send and receive short messages, between six bytes and several kilobytes and offers services for surveillance, tracking and transfer of messages. For more information, see www.orbcomm.com
Orbcomm frequencies and data rates (source: www.orbcomm.com)