D-C.A.B. - Digital Cable
D-S.A.T. - Digital Satelite
D.A.V.I.C. - The Digital Audio Video Council is a worldwide association of bodies concerned with promoting interoperability in audio visual equipment of all kinds, concentrating on standardised interfaces.
DC - Direct Current
D.C.T. - The Discrete Cosine Transform is the technique for getting at the redundancy which is in television images in order to reduce the datarate. It is a fundamental part of the MPEG-2 compression process.
DECODER - The tuner in a Digital set
DEMODULATOR - A device that recovers the original signal from a modulated carrier signal, such that the characteristics of the original are faithfully reproduced. Implements the process of Demodulation.
DIGITAG - DigiTAG is the European equivalent of DTG in the UK, being a consortium of broadcasters and manufacturers working on common standards within the DVB framework with the objective of achieving a European wide market for receiver designs. Digitag operates under the auspices of the EBU.
DIPLEXER - A device that splits a collection of signals into two groups according to the frequency range in which they are located, or combines two groups of signals, each occupying a separate frequency range, into a single collection of signals.
DiSEqC - Digital Satellite Equipment Control. A standardised method for two-way communication between devices in satellite reception systems. Information is exchanged between devices interconnected by standard coaxial cable by means of a modulated 22 kHz tone. DiSEqC is a trademark of Eutelsat.
DISH - See Antenna.
DMUX GROUP - The original name given to meetings of the four terrestrial multiplex operators, BBC, Digital3&4, SDN and ONdigital and now branded as The Digital Network
D.O.C.S.I.S. - DOCSIS is the physical layer and format protocols for cable modems in the USA and seems likely to be adopted in many countries helped, it must be said, by Microsoft's investment in cable companies in many territories. Unfortunately the DVB have their own standard just coming to fruition and it seems likely that both standards will be rolled out over the next few years.
D.O.G. - Digital Originated Graphic. A logo which appears on the screen of most digital television channels and many analogue channels.
DOLBY DIGITAL - A high quality surround sound format using digital signals, with five surround channels and one bass channel.
DOWNLINK - A signals path from satellite to antenna.
D.S.B. - Double Side Band.
D.S.L. - Digital subscriber Line, a method of delivering TV or broadband, or Video on Demand through telephone wires.
D.S.M.C.C. - Digital Storage Media. The DVB defined method adopted for UK DTT for transmitting data in an object carousel.
D.T.G. - Digital Terrestial Group.
D.T.T. - Digital Terrestrial Television, the means of receiving digital television using an aerial. In the UK the company responsible for DTT is Freeview, who are monitored by the ITC
D.T.V. - Digital Television Commercial Division. Providing business opportunities to specialise and concentrate on customers who need specific support on complex installations and require technical expertise in SMATV, MATV, & IRS.
D.V.B. - The Digital Video Broadcasting Project, an industry-led consortium of over 300 broadcasters, manufacturers, network operators, software developers, regulatory bodies and others in over 40 countries committed to designing global standards for the delivery of digital television and data services.
DVD - Digital Versatile Disk - digital storage device commonly used for film/video
DVD-RW - Recordable DVD, another digital recording device - uses DVD format.
D.V.I. - Digital Video Interface. A high-bandwidth digital video connector on some HD televisions and set-top boxes.
D.V.R. - Digital Video Recorder. This is where a set-top box has a built in hard disc drive and allows digital quality video recording without tape.
DYNAMIC MULTIPLEXING - Variation of datarate programme by programme so as to allow simultaneous transmission of other services. Involves a calculated risk that shots within the programme will not exceed the allowed datarate.