电信专业英英词典D-2_电脑电信

　delay - this is the wait time between to specific events, and regarding satellite communications, it is the time it takes for a signal to go from the transmission station up to orbit and through the satellite and back down to the receiving earth station (about 1/4 of a second).

　delete - this terms means to discard (i.e., destroy) information.

　delivery on-orbit - a contractual term describing a service to deliver the satellite at its intended orbital location in space.

　demodulation - this is the process of extracting the electrical signal (i.e., the data) from the carrier signal.

　demodulator - a satellite receiver circuit which extracts or "demodulates" the desired data from from the received carrier signal.

　deviation - the modulation level of an fm signal determined by the amount of frequency the signal is from the frequency of the main carrier signal.

　dial - this refers to the sending out of either pulses or tones with the intent of establishing a connection (i.e., a circuit) with another phone or modem.

　dialup modem - this is a modem that is used over normal telephone lines (i.e., not dsl or cable)

　dial string - this is the string of characters used to contact another device over telephone lines.

　dial tone - this sound signifies that a telephone is ready to receive instruction (i.e., make a call).

　dibit - this is group of two bits.

　digital - referring to communications techniques whereby information and data are encoded as discrete elements in a binary language, as opposed to analog representation of information in variable, but continuous, wave forms.

　dip - this is the act of extracting particular information from a database.

　diplexer - this is a device which combines two transmitters onto one single transmission line.

　dipole - this is an antenna that is fed from the center (such as rabbit ears).

　disconnect - to break a connection (i.e., a circuit) so communication is no longer possible.

　domain - on the internet, a domain is a place to visit with your internet browser.

　door - this is a software program that allows bbs users to run a program while a user is simultaneously using the bbs.

　down - this is a general term that means that something is not currently working.

　downlink - the segment of a satellite circuit that extends from the satellite to the user terminal (such as, but not limited to, a television).

　download - this term means to receive data from another source.

　driver - this is a software program that provides instructions to a computer on how to communicate with peripheral devices, such as printers or modems.

　dte - see data terminal equipment.

　dtmf - see dual tone multi-frequency.

　dtr - see data terminal ready.

　dtv - stands for digital television.