icating with satellites.
satellite link - a radio connection between a satellite and an earth
station permitting communication between them, either one-way (down
link from satellite to earth station - television receive-only
transmission) or two-way (telephone channels).
SHF - super-high-frequency; any radio frequency in the 3,000- to
30,000-MHz range.
shortwave - radio frequencies (from 1.605 to 30 MHz) that fall above
the commercial broadcast band and are used for communication over long
distances.
Solidaridad - geosynchronous satellites in Mexico's system of
international telecommunications in the Western Hemisphere.
Statsionar - Russia's geostationary system for satellite
telecommunications.
submarine cable - a cable designed for service under water.
TAT - Trans-Atlantic Telephone; any of a number of high-capacity
submarine coaxial telephone cables linking Europe with North America.
telefax - facsimile service between subscriber stations via the public
switched telephone network or the international Datel network.
telegraph - a telecommunications system designed for unmodulated
electric impulse transmission.
telex - a communication service involving teletypewriters connected by
wire through automatic exchanges.
tropospheric scatter - a form of microwave radio transmission in which
the troposphere is used to scatter and reflect a fraction of the
incident radio waves back to earth; powerful, highly directional
antennas are used to transmit and receive the microwave signals;
reliable over-the-horizon communications are realized for distances up
to 600 miles in a single hop; additional hops can extend the range of
this system for very long distances.
trunk network - a network of switching centers, connected by
multichannel trunk lines.
UHF - ultra-high-frequency; any radio frequency in the 300- to
3,000-MHz range.
VHF - very-high-frequency; any radio frequency in the 30- to 300-MHz
range.
Telephones - main lines in use: This entry gives the total number of
main telephone lines in use.
Telephones - mobile cellular: This entry gives the total number of
mobile cellular telephones in use.
Television - broadcast stations: This entry gives the total number of
separate broadcast stations plus any repeater stations.
Televisions: This entry gives the total number of television sets.
Terminology: Due to the highly structured nature of the Factbook
database, some collective generic term
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