Telecommunications terms starting with V

130 terms

V number Synonym normalized frequency.
V reference point The interface point in an ISDN environment between the line termination and the exchange termination.
V-series Recommendations Sets of telecommunications protocols and interfaces defined by CCITT (now ITU-T) Recommendations. Note: Some of the more common V.
vacant code (VC) A call-disposition category for a call attempt to an unassigned NPA (numbering plan area) or N. [T1.207-1998]
vaccine program Synonym anti-virus program.
Validation is the process of performing a set of experiments that establish the efficacy and reliability of a technique or procedure or modification thereof.
validation system The system containing the data base information to be used in validation of the telecommunications charge card or billed number screening data. [T1.
value date The date the transfer entry to an account is considered effective; either the day the instruction is received or some future date as stipulated by the…
value-added carrier A company that sells the services of a value-added network.
value-added network (VAN) A network using the communication services of other commercial carriers, using hardware and software that permit enhanced telecommunication services to be…
VAN Acronym for value-added network.
variable length buffer A buffer into which data may be entered at one rate and removed at another rate without changing the data sequence.
variable slope delta modulation See continuously variable slope delta modulation.
Variance A special exemption of a zoning law to allow the property to be used in a manner different from an existing law.
variant An individual that is genetically distinct from others in the population.
variant of a key A new key formed by a nonsecret process with the original key, such that one or more of the nonparity bits of the new key differ from the corresponding…
variation monitor In ac power distribution, a device for sensing deviations of any measured variable, such as voltage, current, or frequency, and capable of initiating a…
vars Abbreviation for volt-amperes reactive.
VC Abbreviation for virtual circuit.
VCR Abbreviation for video cassette recorder. See video recorder.
VDU Visual Display Unit.
vector processor Synonym array processor.
velocity of propagation Of an electrical or electromagnetic signal, its speed in a physical medium such as a coaxial cable or optical fiber.
Verification To confirm the truth or correctness of something. Vitreous humor – The ocular fluid (from within the eye) that is often used as a sample for testing in…
verification authentication information (verification AI) Information used by a verifier to verify an identity claimed through exchange AI [10181-2].
verified development Development of a system or part of a system where the transformation from one representation to another is mathematically proven, or demonstrated to be…
verified off-hook In telephone systems, a service provided by a unit that is inserted on each end of a transmission circuit for the purpose of verifying supervisory signals…
Verifier An entity that verifies the claimants identity by verifying the claimants possession of a token using an authentication protocol.
Vernam cypher An extremely secure cryptographic approach to enciphering messages, wherein each character of a message gets assigned a random character from the key; the…
vertex angle In an optical fiber, the angle formed by the extreme bound meridional rays accepted by the fiber, or emerging from it, equal to twice the acceptance…
vertical portal A Web search engine that locates very precisely a few Web pages of particular interest according to the character strings or subject entered as the search…
vertical redundancy check (VRC) Synonym transverse redundancy check.
Very High Frequency (VHF) Frequencies from 30 MHz to 300 MHz. See electromagnetic spectrum.
Very Low Frequency (VLF) That portion of the radio frequency spectrum from 3 to 30 kHz
vestigial sideband (VSB) transmission Modified AM transmission in which one sideband, the carrier, and only a portion of the other sideband are transmitted.
VF Abbreviation for voice frequency.
VF patch bay See voice frequency primary patch bay.
VFCT Abbreviation for voice frequency carrier telegraph. See voice-frequency telegraph.
VFCTG Abbreviation for voice-frequency carrier telegraph. See voice-frequency telegraph.
VFTG Abbreviation for voice-frequency telegraph.
VHF Very High Frequency.
via net loss (VNL) Pertaining to circuit performance prediction and description that allows circuit parameters to be predetermined and the circuit to be designed to meet…
video 1. An electrical signal containing timing (synchronization), luminance (intensity), and often chrominance (color) information that, when displayed on an…
video codec See codec.
video description An audio narration for television viewers who are blind or visually disabled, which consists of verbal descriptions of key visual elements in a television…
video display terminal Synonym visual display unit. See monitor.
video display unit Synonym visual display terminal. See monitor.
video frame See frame.
video imagery A sequence of video frames. [T1.801.02-1996]
video pair cable Transmission cable containing low-loss pairs with an impedance of 125 ohms; used for telephone carrier circuits, closed-circuit TV, TV pick-ups etc.
video recorder (VCR) Equipment for recording the video waveform so that the mapped images may be stored and later retrieved as the video waveform. [After SMPTE]
video server A server that distributes video images on demand. [2382-pt.35]
video signal description The standard video-signal waveform, measured in IRE units. [After T1.Rpt16-1992]
video teleconference A teleconference that includes video communications. 2. Pertaining to a two-way electronic communications system that permits two or more persons in…
video teleconferencing unit (VTU) Equipment that performs video teleconference functions, such as coding and decoding of audio and video signals and multiplexing of video, audio, data, and…
videoconference See video teleconference.
videophone A telephone that is coupled to an imaging device that enables the call receiver or the call originator, or both, to view one another as on television, if…
view A logical table whose data are not physically stored. You define a view to access a subset of the columns stored in a row, access a set of columns stored…
viewdata A type of information-retrieval service in which a subscriber can (a) access a remote database via a common carrier channel, (b) request data, and (c)…
viewer Application software that enables a user to have read-only access to electronic documents or images. [After 2382-pt.35]
Violation A crime of a less serious nature than a felony or misdemeanor. In Delaware, the statute a person is charged with normally states whether it is a…
virtual call A call, established over a network, that uses the capabilities of either a real or virtual circuit by sharing all or any part of the resources of the…
virtual call capability A service feature in which (a) a call set-up procedure and a call disengagement procedure determine the period of communication between two data terminal…
virtual call facility Synonym virtual call capability.
virtual carrier frequency In radio or carrier systems in which no carrier is transmitted, e.g., single sideband or double sideband with suppressed carrier, the location in the…
virtual channel (VC) The communication channel associated with a virtual channel connection (VCC) that provides for the transport of asynchronous transfer mode (ATM) cells…
virtual channel connection (VCC) A concatenation of VCLs (virtual channel links) that extends between the points where the ATM (asynchronous transfer mode) service users access the ATM…
virtual channel link (VCL) A means of unidirectional transport of ATM cells between the point where a VCI value is assigned and the point where that value is translated or removed.
virtual circuit (VC) A communications arrangement in which data from a source user may be passed to a destination user over various real circuit configurations during a single…
virtual circuit capability A network-provided service feature in which a user is provided with a virtual circuit.
virtual connection A logical connection that is made to a virtual circuit.
virtual data link capability (VDLC) protocol A wideband protocol that is used to transport digital data packets arriving from the channelized side in HDLC frames. [T1.509-1995]
Virtual Domain A domain hosted by a virtual server account.
virtual height The apparent height of an ionized layer, as determined from the time interval between the transmitted signal and the ionospheric echo at vertical…
virtual instruction Synonym teletraining.
virtual local area network (VLAN) A LAN created via software rather than dedicated hardware.
virtual memory A computer will have a limited amount of real memory available to it. Programs often require more memory than the amount of real memory.
virtual network A network that provides virtual circuits and that is established by using the facilities of a real network.
virtual office A work environment in which employees work cooperatively from different locations using a computer network. [After 2382-pt.35] Synonym virtual workplace.
virtual password [An] information system (IS) password computed from a passphrase meeting the requirements of password storage (e.g., 64 bits). [INFOSEC-99]
virtual path See virtual circuit.
Virtual Private Network (VPN) A virtual private network is a logical network that is established, at the application layer of the Open Systems Interconnection (OSI) model, over an…
virtual reality An interactive, computer-generated simulated environment with which users can interact using specialized peripherals such as data gloves and head-mounted…
virtual storage The storage space that may be regarded as addressable main storage by the user of a computer system in which virtual addresses are mapped into real…
virtual terminal (VT) In open systems, an application service that (a) allows host terminals on a multi-user network to interact with other hosts regardless of terminal type…
virtual tributary (VT) A structure designed for transport and switching of sub-STS-1 payloads. There are currently four sizes of VT. [T1.105-1988]
virtual workplace Synonym virtual office.
virtual world A simulated environment that appears to have the characteristics of some other environment, and in which participants perceive themselves as interactive…
Virus (VY-rus) In medicine, a very simple microorganism that infects cells and may cause disease.
virus signature A unique bit string that is common to each copy of a particular virus and that may be used by a scanning program to detect the presence of the virus.
visible spectrum The region of the electromagnetic spectrum that can be perceived by human vision, approximately the wavelength range of 0.4 m to 0.7 m.
visual channel A means for delivering video frames from one point to another; a sequence of frames submitted to the channel input results in a similar (not necessarily…
visual display unit (VDU) See monitor.
visual telephone services A group of audiovisual services including videophone as defined in ITU-T Recommendation F.
vitreous silica Glass consisting of almost pure silicon dioxide (SiO2). Synonym fused silica.
VLF Very Low Frequency.
VNL Abbreviation for via net loss.
vocoder Abbreviation for voice-coder. A device that usually consists of a speech analyzer, which converts analog speech waveforms into narrowband digital signals…
vodas Acronym for voice-operated device anti-sing. A device used to prevent overall voice-frequency singing in a two-way telephone circuit by ensuring that…
vogad Acronym for voice-operated gain-adjusting device. A device that has a substantially constant output amplitude over a wide range of input amplitudes.