SHF—super—high—frequency; any radio frequency in the 3,000- to 30,000-MHz range
SHF—super-high-frequency; any radio frequency in the 3,000- to 30,000-MHz range
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