Broadband Digital Communications
Broadband satellites transmit high-speed data and video directly to consumers and businesses. Markets for broadband services also include interactive TV, wholesale telecommunications, telephony, and point-of-sale communications, such as credit card transactions and inventory control.
Direct-broadcast satellites (DBS) transmit signals for direct reception by the general public, such as satellite television and radio. Satellite signals are sent directly to users through their own receiving antennas or satellite dishes, in contrast to satellite/cable systems in which signals are received by a ground station, and re-broadcast to users by cable.
Environmental monitoring satellites carry highly sensitive imagers and sounders to monitor the Earth's environment, including the vertical thermal structure of the atmosphere; the movement and formation of clouds; ocean temperatures; snow levels; glacial movement; and volcanic activity. Large-scale computers use this data to model the entire earth's atmosphere and create weather forecasts such as those provided by national weather services in the U.S. and abroad.
These satellites are typically self-contained systems that carry their own communications systems for distributing the data they gather in the form reports and other products for analyzing the condition of the environment. Satellites are particularly useful in this case because they can provide continuous coverage of very large geographic regions.
Satellites providing Fixed-Satellite Services (FSS) transmit radio communications between ground Earth stations at fixed locations. Satellite-transmitted information is carried in the form of radio-frequency signals. Any number of satellites may be used to link these stations. Earth stations that are part of fixed-satellite services networks also use satellite news gathering vehicles to broadcast from media events, such as sporting events or news conferences. In addition, FSS satellites provide a wide variety of services including paging networks and point-of-sale support, such as credit card transactions and inventory control.
Providing X-band satellite communications services to governments is a new commercial application with substantial growth potential. SSL has designed and built two X-band satellites, which will be available for lease to government users in the United States and Spain, as well as other friendly and allied nations within the satellites' extensive coverage areas. Government communications use specially allocated frequency bands and waveforms.
Beyond environmental applications, government sensors gather intelligence in various forms, including radar, infrared imaging, and optical sensing.
Mobile Satellite Services
Mobile Satellite Services (MSS) use a constellation of satellites that provide communications services to mobile and portable wireless devices, such as cellular phones and global positioning systems. The satellite constellation is interconnected with land-based cellular networks or ancillary terrestrial components that allow for interactive mobile-to-mobile and mobile-to-fixed voice, data, and multimedia communications worldwide. With repeaters located on orbit, the interference of traditional fixed-ground terminals can be eliminated.