（单词翻译:单击）
DAMA - Stands for Demand-Assigned Multiple Access. This is a way to instantaneously assign telephony channels in a transponder according to the immediate1 traffic demands.
Dash - This is the the character "-".
Data - This term typically refers to anything that is not a voice, and it is, according to AT&T, "a representation of facts, concepts or instructions in a formalized manner, suitable for communication, interpretation2 or processing."
Database - This term refers to a collection of data that is catalogued in a logical way to ensure quick and reliable access.
Data Carrier Detect (DCD) - This is a hardware signal that indicates when a modem3 is online and capable of transmission.
Data Communications Equipment (DCE) - This is a device that translates a digital signal from data terminal equipment (DTE) into a form acceptable to the receiving device.
Data Compression - This is when data file size is reduced by elimination4 unnecessary information.
Data Grade Circuit - This is a circuit, such as a phone line, that is capable and suitable for transmitting data.
Data Link - This term describes communications paths that are used for data transmissions.
Data Set - (1) According to AT&T a data set is modem, but (2) according to IBM, a data set is a collection of data.
Data Set Ready (DSR) - This is a control signal that says that says a modem is ready to begin initial stages of transmission (i.e., configuration5).
Data Terminal Equipment (DTE) - This is equipment that only receives information (i.e., no transmission), such as a printer.
Data Terminal Ready (DTR) - This is another control signal that says that modems6 have completed their initial configuration session and are ready for transmission.
DBS - This stands for Direct Broadcast Satellite, and refers to service that uses satellites to broadcast multiple channels of television programming to home mounted small-dish antennas8, such as those provided by DirecTV or Dish Network.
dBi - The dB power relative to an isotropic source.
dBW - The ratio of the power to one Watt9; it is expressed in decibels11.
DCD - see Data Carrier Detect.
DCE - see Data Communications Equipment.
Decibel10 (dB) - The standard unit used to express the ratio of two power levels. In the communications field, It is used to express either a gain or loss in power after the signal has traveled between the input12 and output devices.
Declination - The offset13 angle of an antenna7 from the axis14 of its polar mount.
Decoder - Also called a receiver, this is a television-top device that converts an electronically scrambled15 television picture into a signal viewable on the TV.
Deemphasis - Reinstatement of a uniform baseband frequency response following demodulation.
Default - This is the factory setting or configuration of software or hardware.
