Inmarsat (International Maritime Satellite) is perhaps the most reliable communications method in the marine industry, however it is shadowed in the Polar Regions by the curvature of the earth. All Inmarsat satellites are in a geo-synchronous orbit above the equator. There are several technologies employed in this system and they are identified as Inmarsat A, Inmarsat B, Inmarsat C, Inmarsat M4 and Fleet 77. Inmarsat A is the earliest design with analogue voice and digital telex; Inmarsat A systems are no longer being produced or licensed. Inmarsat B differs from Inmarsat A in that it is digital voice and telex and capable of a 64 Kilobit ISDN (Integrated Services Digital Network) connections as well as direct Internet interfacing. Inmarsat C is a store and forward telex system with limited data capabilities. Unlike Inmarsat A and B, the Inmarsat C has no voice capabilities. Inmarsat M4 is a totally digital system primarily used in conjunction with ISDN and is both data and multi-telephone capable. Mini M a sub system of M provides digital voice and low speed data connections. Fleet 77, the newest of Inmarsat offerings, provides digital voice and data connect capabilities. Unlike the other Inmarsat technologies, Fleet 77 is data connected to the shore station continuously. Usage fees are based upon the amount of data transferred and not the connect time.
The Inmarsat system consists of nine satellites in geo-stationary orbit and 40 Land Earth Stations (LES) in 31 different countries. Each Inmarsat satellite orbits 22,223 miles (35,786 km) above the earth and covers up to one third of the earth's surface. Four of the nine satellites provide overlapping coverage of the entire globe. The remaining satellites are used as spares. Only the earth's extreme poles are without coverage. The LES connect the Inmarsat satellite system to the world's fixed communication networks. Most Inmarsat phone calls are made on the world's land masses. Inmarsat's new spot beam technology concentrates satellite power on those areas.
Rice Electronics provides customers around the world with a comprehensive array of reliable, cost-effective and efficient Inmarsat-C network services. In addition to Internet, e-mail, fax and telex, we offer numerous unique services and end-to-end solutions.
Inmarsat B is a global communications system that extends modern digital technology to the mobile satellite communications field. Inmarsat B offers very high quality voice, telex, medium and high-speed data (64 kbps), and fax for much less than the traditional Inmarsat A service. Inmarsat B offers all the applications currently available with Inmarsat A.
Inmarsat B appeals particularly to high volume users of voice and data. Typical industries that use Inmarsat B service are offshore exploration, cruise ships, deep sea shipping and government agencies.
Inmarsat M4 service brings the technologies of the world's most advanced communication systems to its most remote places. Its portable, lightweight and easy to carry multimedia satellite terminal allows users to get HSD (high speed data) and PSTN (public switched telephone network) high quality voice connectivity from countries where telecommunications are unavailable or unreliable.
With the appropriate software and hardware Inmarsat M4 service supports HSD applications such as Internet Web access and Email, G3/G4 fax, large file transfers, video conferencing and high-resolution image transfers. Additionally services such as remote diagnostics, telemedicine, remote monitoring, encryption systems (STU III/STE), audio quality broadcasting, store-and-forward video and data streaming are also available with Inmarsat M4 global service. Inmarsat M4 is optimized to work with ISDN (Integrated Services Digital Network) providing 64kbps digital connectivity and ensuring reliable data transmissions.
Achieving a flow of accurate, up-to-date information from, and exercising control over, remote installations has always been a complex and expensive exercise. Now Inmarsat D+ satellite communication services offer a low-cost, highly-reliable mobile solution for supervisory control and data acquisition systems (SCADA).
The range of possible D+ applications is nearly endless: from tracking trucks in Belgium, buses in Namibia, sail boats in Argentina, or railwagons in Central Africa, to opening banking vaults remotely in Brazil, engine monitoring in South Africa, monitoring of ATM machines in Venezuela or power lines in South America.
D+ is a global mobile telecommunications system, which supports bi-directional store-and-forward short message data communications. It is the perfect high quality, affordable communication solution for those requiring short data messaging across wide or remote areas. No matter how inhospitable a location or how extended a network, the D+ system can link mobile units anywhere in the world to the computers that control them.
Data packets can be transmitted from remote (mobile) sites at pre-programmed time-intervals. Alternatively, D+ terminals can be interrogated for data, or control instructions can be sent to activate or adjust their remote functions. The control station (being a computer system such as a portable PC or server) running application software designed for a specific end-to-end solution, (e.g. tracking and tracing, telemetry or person to person messaging) is linked through the terrestrial telephone network with the Inmarsat-D+ Land Earth Station. 'From-terminal' D+ messages are generally sent in the form of macro-code. This can comprise up to 64 bits of data, enough for GPS position reports, alarms or telemetry data and an unlimited number of application-defined macro-codes. Every message is automatically identified with a terminal and receives a date/time stamp when it passes through the Land Earth Station, a few seconds after being sent.
'To-terminal' D+ messages have many different uses, including simple commands to the remote location, configuration instructions, position or status polling and text messages. Up to 2000 bits of information can be sent in a single to-terminal message, though it is more economic to minimize the amount of data using macro-codes.
D+ satellite communication services perfectly meet the needs of the international road transport industries. Locating, tracking and monitoring vehicle fleets for better utilization, keeping track of sensitive and high value loads, and the vehicles that carry them, no matter where they go.
A vehicle, no matter how remote its route, is never out of range with Inmarsat D+, making it also an ideal communications system for security alerting. A sensor triggered alarm signal can automatically include location and direction of travel information, enabling the control center or the authorities to take action or send assistance immediately.
D+ terminals are very small satellite transceivers (comparable in size to a portable CD player) containing built-in GPS functionality and include a RS232 port for connecting sensors, controllers and displays are light, small and easy to install.
The Global Satellite Communications System for Fleet F77 Voice and Data Services: Fleet managers, ship captains, and yacht owners require more than just reliable communications. They need to stay in touch at all times to receive up-to-the-minute information critical to vessel safety, operation, and business. Fleet F77 provides both the high quality and speed of a 64 Kbps mobile Integrated Services Digital Network (ISDN) service and the flexibility and “always on-line” capability of the Inmarsat Mobile Packet Data Service (MPDS). Captains, crews, fleet managers, and vessel owners can now have unparalleled real-time access to the information they need: e-mail, the Internet, corporate Intranets, and Virtual Private Networks (VPNs). Rice Electronic's array of F77 products offers the unmatched versatility and reliability you need to stay safe and stay in touch, almost anywhere on earth.