（单词翻译:单击）
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.
Deviation2 - The modulation1 level of an FM signal determined3 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 modem4.
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 discrete5 elements in a binary6 language, as opposed to analog7 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 antenna8 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.
Domain9 - On the internet, a domain is a place to visit with your internet browser10.
Door - This is a software program that allows BBS users to run a program while a user is simultaneously11 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 peripheral12 devices, such as printers or modems13.
DTE - see Data Terminal Equipment.
DTMF - see Dual14 Tone Multi-Frequency.
DTR - see Data Terminal Ready.
DTV - Stands for Digital Television.
