DPDCH
Initialism of dedicated physical data channel.
Electrical engineering
450 entries in this trade.
DPLL
Initialism of digital phase-locked loop.
DSC
Initialism of digital selective call, a feature that allows a VHF radio to call another VHF selectively (as opposed to a call that is repeated by all receivers that are on within the range of the caller).
dwell time
The length of time that a thing or person remains in a given state.
dynamic IP address
An IP address which changes periodically, when each time a user connects to their internet service provider.
dynamo
An electricity generator; a dynamo-electric machine.
Early effect
The variation in the effective width of the base in a bipolar junction transistor due to a variation in the applied base-to-collector voltage.
EDFA
Initialism of Erbium-Doped Fiber Amplifier.
EDGE
Acronym of Enhanced Data rates for GSM Evolution.
EGPRS
Initialism of enhanced General Packet Radio Service.
electric current
The net charge that passes through some cross-section of a conducting material (in one direction), per unit time.
electric field
A region of space around a charged particle, or between two voltages, which exerts a force on charged objects in its vicinity.
electric flux
The measure of flow of the electric field through a given area.
electric main
The principal or main electrical supply line that distributes electricity from the utility grid to a building or home.
electric potential
The potential energy per unit charge at a point in a static electric field.
electric power transmission
The movement of large amounts of electrical energy from the site of generation to a substation.
electrical fault
A defect that forms from a fault current.
electrolytic capacitor
A capacitor that uses an electrolyte as one of its capacitative plates.
electron multiplier
A vacuum-tube structure that multiplies incident charges by means of secondary emission.
electrostatic force
Coulomb force, the attraction or repulsion between particles based on their electric charge.
ELFEXT
Initialism of equal-level far-end crosstalk.
EMC
Initialism of electromagnetic compatibility.
emitter-coupled logic
A logic family that achieves high speed by using an overdriven BJT differential amplifier with single-ended input.
end-node
A device that connects to a network and is the endpoint for data communication.
engaged tone
An audible signal to the calling party that indicates failure to complete the requested connection; a busy signal.
EPROM
Initialism of erasable programmable read-only memory.
equivalence gate
a logic gate performing a Boolean logic equivalence operation; an XNOR gate.
EROI
Initialism of energy return on investment.
ERP
Initialism of effective radiated power or equivalent radiated power.
escape character
A single metacharacter, usually a control code, which in a sequence of characters signifies that what is to follow takes an alternative interpretation. The term escape sequence refers to the escape character and the subsequent character or characters so modified.
escape sequence
An escape character together with subsequent characters, not output as written, but specifying a particular behaviour.
eSIM
Initialism of embedded SIM (“virtual SIM that is integrated in the cellular device”).
ESR
Initialism of equivalent series resistance.
essential mesh
In mesh analysis: a simple mesh (loop) which does not contain any other meshes.
essential prime implicant
A prime implicant on a Karnaugh map which "covers" at least one 1 which is not covered by any other prime implicant.
exit code
A sequence of digits that must be dialled before the target number when placing an international call from a given country.
exit node
A server that allows traffic to leave a secure network and enter the public internet.
extension
A numerical code used to indicate a specific telephone in a telecommunication network.
extension reel
An extension lead that rolls up, usually into the socket end, which in some cases has more than one socket on it (often 2 or 4).
extremely low frequency
The band of radio frequencies from 3 to 30 hertz.
FAB
Used to acknowledge that a message has been received and understood.
fall time
The amount of time taken for the amplitude of a pulse to decrease from a specified value to another specified value.
far field
The region sufficiently distant from a radio antenna for angular field distribution to be independent of distance.
fast busy signal
An audible signal on a voice phone line that sounds more frequently than a standard busy signal, indicating that no transmission path to the called phone number is available.
fast telegram
A telegram sent during either the day or night at a full rate for immediate delivery, typically with a minimum charge for 10 words or less.
fault current
An irregularity in an electric current that leads to an electrical fault.
FCD
Initialism of floating car data (“a method to determine the traffic speed on a road network”).
FDD
Initialism of frequency-division duplex.
FDR
Initialism of false transmit format detection ratio (in UMTS).
feed-through
A hermetically sealed connection between two volumes.
field emission display
a flat panel display technology that uses large-area field electron sources to provide electrons that strike coloured phosphors to produce a colour image. In a general sense, an FED consists of a matrix of cathode ray tubes, each tube producing a single sub-pixel, grouped in threes to form red-green-blue (RGB) pixels.
flash cut
A change made to a complex system with immediate effect, one made without a phase-in period.
flashover voltage
The voltage at which an electric discharge occurs between two electrodes that are separated by an insulator.
FMNP
Initialism of full mobile number portability.
forward echo
The propagation of a signal reflection in the same direction as the original signal and consisting of energy reflected back by one discontinuity and then forward again by another discontinuity.
Fourier transform
A particular integral transform that when applied to a function of time (such as a signal), converts the function to one that plots the original function's frequency composition; the resultant function of such a conversion.
FPGA
Initialism of field-programmable gate array.
frequency assignment
The process of authorizing a specific frequency, group of frequencies, or frequency radio band to be used at a certain location under specified conditions, such as bandwidth, power, azimuth, duty cycle, or modulation.
frequency band
Synonym of band (“a designated range of radio frequencies used for wireless communication”)
FTTD
Initialism of fiber to the desk/desktop.