577-xxxx, where 011 is the international access code for station-to-
station calls; 01 is for calls other than station-to-station calls,
[34] is the country code for Spain, (1) is the city code for Madrid,
577 is the local exchange, and xxxx is the local telephone number. An
international direct dial telephone call placed from another country to
the US would be as follows: international access code + [1] (202) 939-
xxxx, where [ 1] is the country code for the US, (202) is the area code
for Washington, DC, 939 is the local exchange, and xxxx is the local
telephone number.

Telephone system: This entry includes a brief general assessment of
the system with details on the domestic and international components.
The following terms and abbreviations are used throughout the entry:

Arabsat - Arab Satellite Communications Organization (Riyadh, Saudi
Arabia).

Autodin - Automatic Digital Network (US Department of Defense).

CB - citizen's band mobile radio communications.

Cellular telephone system - the telephones in this system are radio
transceivers, with each instrument having its own private radio
frequency and sufficient radiated power to reach the booster station in
its area (cell), from which the telephone signal is fed to a telephone
exchange.

Central American Microwave System - a trunk microwave radio relay
system that links the countries of Central America and Mexico with each
other.

Coaxial cable - a multichannel communication cable consisting of a
central conducting wire, surrounded by and insulated from a cylindrical
conducting shell; a large number of telephone channels can be made
available within the insulated space by the use of a large number of
carrier frequencies.

Comsat - Communications Satellite Corporation (US).

DSN - Defense Switched Network (formerly Automatic Voice Network or
Autovon); basic general-purpose, switched voice network of the Defense
Communications System (US Department of Defense).

Eutelsat - European Telecommunications Satellite Organization (Paris).

Fiber-optic cable - a multichannel communications cable using a thread
of optical glass fibers as a transmission medium in which the signal
(voice, video, etc.) is in the form of a coded pulse of light.

GSM - a global system for mobile (cellular) communications devised by
the Groupe Special Mobile of the pan-European standardization
organization, Conference Europeanne des Posts et Telecommunications
(CEPT) in 1982.