alarm centerA location that receives local and remote alarms. Note: An alarm center is usually in a technical control facility.
alarm eventAn instantaneous occurrence that changes at least one of the attributes of the alarm status of an object.
alarm indication signal (AIS)A signal transmitted in lieu of the normal signal to maintain transmission continuity and to indicate to the receiving equipment that there is a…
alarm indicatorA device that responds to a signal from an alarm sensor. Note: Examples of alarm indicators include bells, lamps, horns, gongs, and buzzers.
alarm sensorIn communications systems, any device that (a) can sense an abnormal condition within the system and provide a signal indicating the presence or nature of…
alarm statusA set of attributes that describes the alarms currently defined for an object, for example, perceived severity, alarm state, etc.
alarm surveillanceA set of functions that enables the monitoring or interrogation (or both) of the telecommunications network concerning alarm-related events or conditions.
ALERTAutomated Local Event Reporting in Real Time. Network of automatic raingauges that transmit via VHF radio link when precipitation occurs.
Alert engineA matching engine which performs matching of incoming documents against stored queries (triggers). A match generates an alert.
Alert queryAn alert query is the set of filtering conditions an end-user or external application sends to the Alert Engine.
alerting signalA signal used by the network to indicate the presence of an incoming call. It consists of a ringing signal periodically interrupted by silent (no ringing…
AlertsTo notify users of changes to existing information or new information add an alert to track new matches to search queries, changes to content in an area…
AlexaAmazon.com owned search service which measures website traffic. Alexa is heavily biased toward sites that focus on marketing and webmaster communities.
AlgorithmA detailed formula or set of steps for solving a particular problem. To be an algorithm, a set of rules must be unambiguous and have a clear stopping…
algorithm identifierIn encryption, a unique identifier or recognizer for a given encryption or hash algorithm, together with any required parameters. [After X9.31-1]
algorithmic languageAn artificial language established for expressing a given class of algorithms.
alias point codeA Signaling System No. 7 (SS7) address that is shared by more than one system supporting the same GTT (global title translation) function (or other SS7…
aliasesMultiple references to a single object. Messages may be sent to the object via any of its aliases. A resulting state change will be detectable by all.
ALIASINGWhen computer graphics output has jagged edges or a stair-stepped, rather than a smooth, appearance when magnified.
Aliasing (redirecting)Using a fictitious address with which to send and receive e-mail. Typically done to avoid having people write to long "real" e-mail addresses or if…
aligned bundleA bundle of optical fibers in which the relative spatial coordinates of each fiber are the same at the two ends of the bundle.
alignment error rate monitoringA procedure by which the error rate of a signaling link is measured during the initial alignment process. [After T1.110.2-1992] [After T1.226-1992]
alignment jitterThe short-term variations between the optimum sampling instants of a digital signal and the sampling clock derived from it. [T1.Rpt17-1993]
all-silica fiberAn optical fiber composed of a silica-based core and cladding. Note: The presence of a protective polymer overcoat does not disqualify a fiber as an…
Allan varianceOne half of the time average over the sum of the squares of the differences between successive readings of the frequency deviation sampled over the…
allcallIn adaptive high-frequency (HF) radio automatic link establishment (ALE), a general broadcast that does not request responses and does not designate any…
Allocated Availability RequirementThe requirement probability that an element is available to perform its function as allocated by the SDS.
Allocation(1) An authorization by a designated official of a DoD component making funds available within a prescribed amount to an operating agency for the purpose…
allocation (of a frequency band)Entry in the Table of Frequency Allocations of a given frequency band for the purpose of its use by one or more (terrestrial or space) radiocommunication…
AllotmentAn area of land where one or more livestock operators graze their livestock. Allotments generally consist of BLM lands but may also include other…
allowAn allow results from a statement that has effect=allow, assuming any stated conditions are met. Example: Allow requests received before 1:00 p.m.
Allow phraseA custom word or phrase that the administrator sets for the Content Filter agent to enable the processing of e-mail messages to Exchange Server 2007…
AllTheWebSearch engine which was created by Fast, then bought by Overture, which was bought by Yahoo.
alphabetAn ordered set of all the letters used in a language, including letters with diacritical signs where appropriate, but not including punctuation marks. 2.
alphabet translationDeprecated synonym for alphabet transliteration. See alphabet transliteration.
alphabet transliterationThe substitution of the characters of one alphabet for the corresponding characters of a different alphabet, usually accomplished on a…
alphabetic character setA character set that contains letters and may contain control characters, special characters, and the yyspace character, but not digits.
alphabetic codeA code according to which data are represented through the use of an alphabetic character set.
alphabetic filing systemA filing system in which files and documents are arranged in alphabetic order from A to Z See also numeric filing system.
alphabetic stringA string consisting solely of letters from the same alphabet. 2. A character string consisting solely of letters and associated special characters from…
alphabetic wordA word consisting solely of letters from the same alphabet. 2. A word that consists of letters and associated special characters, but not digits.
alphanumericCharacters composed of letters, numbers (and sometimes punctuation marks). Excludes control characters.
alphanumeric character setA character set that contains both letters and digits, special characters, and the yyspace character.
alphanumeric codeA code derived from an alphanumeric character set. 2. A code that, when used, results in a code set that consists of alphanumeric characters.
alphanumeric dataData represented by letters, digits, and sometimes by special characters and the yyspace character.
AltA character on your account other than your main character.
Alt AttributeBlind people and most major search engines are not able to easily distinguish what is in an image.
Alt tagsAlt tags alternate text associated with a web page graphic that gets displayed when the Internet user hovers the mouse over the graphic.
AltAirProject name for the feasibility demonstration of a short range, air drop, ballistic missile target, dropped from a C-130 cargo aircraft. 16
AltaVistaSearch engine bought out by Overture prior to Overture being bought by Yahoo. AltaVista was an early powerhouse in search, but on October 25, 1999 they…
altazimuth mountA mounting, e.g., for a directional antenna, in which slewing takes place in (a) the plane tangent to the surface of the Earth or other frame of reference…
AlterationAny change involving an erasure or rewriting in the date, amount, or payee of a check or other negotiable instrument.
alternate access providerA company that enters a market area as a competitive service provider (CAP) to provide exchange service in competition with one or more existing exchange…
alternate carrier routing (ACR)A special advanced intelligent network (AIN) feature supporting Government Emergency Telecommunications Service (GETS) calls.
alternate mailA mail system other than Lotus Notes mail.
alternate mark inversion (AMI) signalA pseudoternary signal, representing binary digits, in which (a) successive "marks" are of alternately positive and negative polarity and the absolute…
alternative routingIn signaling, the process of allocating substitute routes for a given signaling traffic stream in case of failure(s) affecting the signaling links or…
AlternativesCourses of action that may meet the objectives of a proposal at varying levels of accomplishment, including the most likely future conditions without the…
altitude of the apogee or of the perigeeThe altitude of the apogee or perigee above a specified reference surface serving to represent the surface of the Earth.
amateur serviceA radiocommunication service for the purpose of self-training, intercommunication and technical investigation carried out by amateurs, that is, by duly…
amateur stationA station in the amateur service. [NTIA] [RR]
amateur-satellite serviceA radiocommunication service using space stations on Earth satellites for the same purposes as those of the amateur service. [NTIA] [RR]