电信专业英英词典A-2（在线收听）

　　Analog - Transmitting information that is characterized by continuously variable quantities (such as with AM or FM). This is different from digital transmission, which is characterized by discrete bits of information transmitted in numerical steps.

　　Analog-to-Digital Conversion (ADC) - Converting analog signals to their digital representation. (DAC represents the reverse translation.)

　　ANIK - The Canadian domestic satellite system that transmits the CBC's (Canadian Broadcasting Corporation's) network feeds throughout Canada. This system also carries data and long distance voice services throughout Canada.

　　Anonymous - An unknown author of a software program or message.

　　ANSI - This stands for American National Standards Institute, which was founded in 1918 and creates voluntary standards for data transmissions, protocols, and high-level languages.

　　Answer Back - This is a signal sent to a transmitter of information that, in effect, says "I am ready to receive information now." It can also signify the successful reception of information.

　　Answer Mode - A modem's condition in which it is ready to receive data.

　　Answer Supervision - A signal sent to the telephone company's central office that says a call has been connected (primarily used for long-distance phone calls to start the billing time).

　　Antenna - A device for transmitting and receiving radio waves. Depending on their intended use, antennas could be a single piece of wire, a di-pole, a grid, a helix, a parabolic satellite dish, etc.

　　Aperture - A cross-sectional area of the part of the antenna that is to be exposed to the received satellite signal.

　　Apogee - The point in an elliptical satellite orbit which is farthest from the surface of the earth.

　　Apogee Kick Motor (AKM) - The rocket motor that is fired to deploy the satellite into geostationary orbit.

　　Append - To add the contents of one thing to that of another.

　　Archive - This is a backup of a file in compressed or uncompressed form.

　　Area code - This is a 3-digit number, preceding normal 7-digit telephone numbers, that are used by the telephone company to designate a geographic billing area in the US.

　　ASCII - This stands for American Standard Code of Information Interchange, and it is a popular code for representing letters, numbers, and punctuation into a digital format.

　　Asterisk - This is the character "*".

　　Asynchronous Transmission - This is a method of data transmission that allows characters to be sent irregular intervals.