FQDNFully Qualified Domain Name. The complete name of a specific computer on the Internet, consisting of the computer's host name and its domain name.
FQDN (fully qualified domain name)A Domain Name System (DNS) that has been stated unambiguously to indicate with certainty its location in the domain namespace tree.
fractional frequency fluctuationThe deviation of the frequency of an oscillator from its nominal constant frequency, normalized to the nominal frequency.
fractional frequency offsetA measure of the deviation of the frequency of a signal from a reference, expressed as a ratio.
fractional T1In telecommunications, a portion of the 1.544 Mb/s (T1-aggregate) bit stream; the available fractions being determined by the type of multiplexer used to…
FragmentationProcess by which habitats are increasingly subdivided into smaller units, resulting in their increased insularity as well as losses of total habitat area.
Fragmentation WarheadA warhead, which releases small solid objects to damage or destroy its targets.
FrameThe stationary portion of a window unit that is affixed to the facade and holds the sash or other operable portions of the windows.
frame alignmentIn the reception of framed digital data, the extent to which a received frame is correctly aligned with respect to the clock at the receiver. 2.
frame durationThe time between the beginning of a frame and the end of that frame. Note: For fixed-length frames, at a fixed data rate, frame duration is constant.
frame grabberA device that can seize and record a single frame of video information out of a sequence of many frames.
frame matchingThe process of comparing one sequence of frames with another sequence of frames in order to determine the correspondence between frames in each sequence…
frame overheadBits (binary digits) that are added at regular intervals to a digital signal at the sending end of a digital link and used to provide network functions…
frame pitchThe distance, time, or number of bits between corresponding points, i.e., significant instants, in two consecutive frames. [From Weik '89]
frame rateThe number of frames transmitted or received per unit time. Note 1: The frame rate is usually expressed in frames per second.
frame relayAn interface protocol for statistically multiplexed packet-switched data communications in which (a) variable-sized packets (frames) are used that…
frame relaying protocol data unit (FPDU)A data unit exchanged at the user-network interface and having a format based on that defined in CCITT Recommendation Q.921 (1988) (ANSI T1.602). [T1.
frame sizeThe number of octets after the address field and before the frame check sequence (FCS) field in a frame.
frame slipIn the reception of framed data, the loss of synchronization between a received frame and the receiver clock, causing a frame misalignment event, and…
frame synchronizationOf a received stream of framed data, the process by which incoming frame alignment signals, i.e., distinctive bit sequences, are identified, i.e.
frame synchronization patternIn digital communications, a prescribed recurring pattern of bits transmitted to enable the receiver to achieve frame synchronization.
frame-alignment signalIn the transmission of data frames, a distinctive sequence of bits used to accomplish frame alignment.
frame-alignment time slotA time slot occupying the same relative position in every frame and used to transmit the frame alignment signal. [T1.107-1988]
frame-rate conversionWith respect to television or other video display technologies, the process of transforming from one standard frame rate to another, using an algorithm.
framed interfaceAn interface through which information flow is partitioned into physical, periodic frames consisting of overhead information and an information payload.
FramesAn HTML technique for combining two or more separate HTML documents within a single web browser screen.
FramesetA web page that is made up of frames. A useful analogy: if the individual frames that make up the frameset are the 'children,' then the frameset is the…
FramingThe structural materials and elements used to construct a wall.
framing bitA bit used for frame synchronization. 2. In a bit stream, a bit used in determining the beginning or end of a frame.
Free Electron Laser (FEL)A type of laser, which generates radiation by the interaction of an electron beam with a static magnetic or electric field.
free netA radio net in which any station may communicate with any other station in the net without first obtaining the permission of the net-control station.
Free RocketA rocket not subject to guidance or control in flight.
free routingThe routing of messages in such a manner that they are forwarded toward their destination or addressee over any available channel without dependence upon…
free spaceA theoretical concept of space devoid of all matter. Note: Free space also implies remoteness from material objects that could influence the propagation…
free text searchA search in which the search term is expressed as free-form text.
free-running capabilityIn a synchronized oscillator, the capability to operate in the absence of a synchronizing signal.
free-space couplingCoupling of magnetic, electric, or electromagnetic fields that are not confined to a conductor.
free-space lossThe signal attenuation that would result if all absorbing, diffracting, obstructing, refracting, scattering, and reflecting influences were sufficiently…
free/busy statusThe availability of a person. In addition to free and busy, the status can also be out-of-office (OOF) or tentative. [Exchange 2003]
Freedom of Information ActA U.S. federal law created to ensure public access to government records A term commonly used to refer to this type of legislation Also referred to as…
Freedom of Information Act (FOIA) RequestA request, made based on the provisions of the Freedom of Information Act, for access to restricted information in Federal records held by NARA, including…
freely availableMeans you don't have to pay money to get it, but the copyright on it may still belong to someone else (like Larry).
freely redistributableMeans you're not in legal trouble if you give a bootleg copy of it to your friends and we find out about it.
freenetA system of computer networks (usually funded by individuals or organizations) consisting of community-based bulletin board systems with, e.g.
freewareHistorically, any software that you give away, particularly if you make the source code available as well. Now often called open source software.
freeze dryingprocess of stabilizing water-soaked documents by freezing them to prevent further damage from water in its liquid state See also vacuum drying, vacuum…
freeze frameA frame of visual information that is selected from a set of motion video frames, and is held in a buffer.
freeze frame televisionTelevision in which fixed ("still") images are transmitted sequentially at a rate far too slow to be perceived as continuous motion by human vision.
freeze-outThe condition that occurs when an earlier nonactive speaker on an input transmission trunk channel becomes active and cannot immediately be assigned to a…
freeze-out fractionThe ratio of the total time that the individual channels experience the freeze-out condition to the total time of the active intervals, and their…
FrequencyThe number of cycles through which an alternating current passes per second; in the U.S.
frequency accuracyThe degree of conformity to a specified value of a frequency.
frequency agingOf an oscillator, the change in frequency, over time, caused by internal changes in oscillator parameters even when external factors, such as environment…
frequency allotmentSee allotment (of a radio frequency or radio frequency channel).
frequency assignmentAuthorization, given by an Administration, for a radio station to use a radio frequency or radio frequency channel under specified conditions 2.
frequency assignment authorityThe power granted an Administration, or its designated or delegated leader or agency via treaty or law, to specify frequencies, or frequency bands, in the…
frequency averagingThe process by which the relative phases of precision clocks are compared for the purpose of defining a single time standard. 2.
frequency compatibility1. Of an electronic device, the extent to which it will operate at its designed performance level in its intended operational environment (including the…
frequency departureThe difference between the instantaneous frequency of a digital signal and the long-term average frequency of that signal. [T1.Rpt17-1993] 2.
frequency deviationThe amount by which a frequency differs from a prescribed value, such as the amount an oscillator frequency drifts from its nominal frequency. 2.
frequency dispersalAn electronic counter-countermeasure (ECCM) in which communications nets' operating frequencies are widely separated from each other, causing a…
frequency displacementThe end-to-end shift in frequency that may result from independent frequency translation errors in a circuit.
frequency diversityTransmission and reception in which the same information signal is transmitted and received simultaneously on two or more independently fading carrier…
frequency driftAn undesired progressive change in frequency with time. Note 1: Causes of frequency drift include component aging and environmental changes.
frequency fluctuationA short-term variation, with respect to time, of the frequency of an oscillator.
frequency flutterA deviation of frequency that generally results from irregular motion of the recording medium during the recording, duplication, or reproduction. [T1.
frequency froggingThe interchanging of the frequencies of carrier channels to accomplish specific purposes, such as to prevent feedback and oscillation, to reduce…
frequency guard bandA frequency band deliberately left vacant between two channels to provide a margin of safety against mutual interference.
frequency hopping[The] repeated switching of frequencies during radio transmission according to a specified algorithm, to minimize unauthorized interception or jamming of…
frequency hourOne frequency used for one hour regardless of the number of transmitters over which it is simultaneously broadcast by a station during that hour. [47CFR]