Telecommunications — page 34 of 85

Telecommunications terms

3301. full duration at half maximum (FDHM) Full width at half maximum in which the independent variable is time. See full width at half maximum.
3302. full load level (FLL) The peak voltage level of a nominal 400-Hz sine wave required to excite the analog-to-digital converter of the transmit channel unit to the extremes of…
3303. full modulation In an analog-to-digital converter, the condition in which the input signal amplitude has just reached the threshold at which clipping begins to occur.
3304. full processing All processing functions required to recover the information bits from a received signal.
3305. full width at half maximum (FWHM) An expression of the extent of a function, given by the difference between the two extreme values of the independent variable at which the dependent…
3306. full-duplex (FDX) circuit A circuit that permits simultaneous transmission in both directions.
3307. full-duplex (FDX) operation Synonym duplex operation.
3308. full-motion operation In television, a video frame update rate that provides the appearance of full motion without flicker or smear problems.
3309. fully connected mesh network See network topology.
3310. fully connected topology See network topology.
3311. fully intermateable connectors Connectors from one source that mate with complementary components from other sources without mechanical damage and with transmission properties…
3312. fully qualified domain name (FQDN) The complete name of a specific computer on the Internet, consisting of the computer's host name and its domain name.
3313. function signal A set of signal elements that is used to transmit or represent a function-control character that actuates a control function, such as carriage return…
3314. functional component (FC) In intelligent networks, an elemental call-processing component that directs internal network resources to perform specific actions, such as collecting…
3315. functional profile A standardization document that characterizes the requirements of a standard or group of standards, and specifies how the options and ambiguities in the…
3316. functional signaling In an integrated services digital network (ISDN), signaling in which the signaling messages are unambiguous and have clearly defined meanings that are…
3317. functional signaling link A combination of a communications link and the associated transfer control functions.
3318. Functional Testing The portion of testing in which the advertised features of a system are tested for correct operation.
3319. functional unit 1. An entity of hardware, software, or both, capable of accomplishing a specified purpose. 2. A functionally distinct part of a basic component [ITSEC].
3320. functionality The ability of equipment to operate as expected during actual service conditions in a central office. [T1.304-1989]
3321. functionality class A predefined set of complimentary security enforcing functions capable of being implemented in a Target of Evaluation [ITSEC].
3322. fundamental Of a periodic wave, the sinusoidal component, i.e., Fourier component, having the lowest frequency.
3323. fundamental mode The lowest order mode of a waveguide. Note: In optical fibers, the fundamental mode is designated LP01 or HE11.
3324. furcate Synonym break out.
3325. Fuse A safety device consisting of a short length of relatively fine wire, mounted in a holder or contained in a cartridge and connected as part of an…
3326. fused silica Synonym vitreous silica.
3327. Fusion The combining of lighter elements into heavier ones. For lighter elements (e.g., hydrogen, helium) this process releases energy.
3328. fusion splice In fiber optics, a splice created by localized heating of the ends of the two fibers to be joined.
3329. FWHM Abbreviation for full width at half maximum.
3330. FX Abbreviation for fixed service, foreign exchange service.
3331. gain The ratio of output current, voltage, or power to input current, voltage, or power, respectively. Note 1: Gain is usually expressed in dB.
3332. gain hit See yyhit.
3333. gain medium An active medium, device, or system in which amplification of input occurs with or without feedback.
3334. gain of an antenna Synonym antenna gain.
3335. galactic radio noise Synonym cosmic noise.
3336. gamma correction In video, the insertion of a nonlinear output-input characteristic for the purpose of changing the system transfer characteristic.
3337. gap A missing section on one of the strands of double-stranded DNA. The DNA will therefore have a single-stranded region.
3338. gap loss The power loss that occurs when an optical signal is transferred from one fiber to another that is axially aligned with it, but longitudinally separated…
3339. gap-loss attenuator An optical attenuator that exploits the principle of gap loss to reduce the optical power level when inserted in-line in the fiber path; e.g.
3340. gaps Periods of no speech activity or low-energy content signals present in the access channel of a wideband packet network. [T1.312-1991]
3341. garble 1. An error in transmission, reception, encryption, or decryption that changes the text of a message or any portion thereof in such a manner that it is…
3342. Gate A device that controls the flow in a conduit, pipe, or tunnel without obstructing any portion of the waterway when in the fully open position.
3343. gateway An element that contained a node on the SDS backbone network as well as on some other network(s) and would have performed protocol and format conversions…
3344. gating The process of selecting only those portions of a wave between specified time intervals or between specified amplitude limits. 2.
3345. gaussian beam A beam of light whose electric field intensity distribution is gaussian. Note: When such a beam is circular in cross section the intensity at distance r…
3346. gaussian filter A filter having a response curve (magnitude versus frequency) that approximates an ideal gaussian curve.
3347. gaussian pulse A pulse that has a waveform described by the gaussian distribution. Note: In the time domain, the amplitude of the waveform is given by where A is the…
3348. Gb/s Abbreviation for gigabytes per second. See International System of Units.
3349. GBH Abbreviation for group busy hour.
3350. GCT Abbreviation for Greenwich Civil Time. See Coordinated Universal Time.
3351. GDF Abbreviation for group distribution frame.
3352. gel support medium (agarose) that holds DNA molecules in place during the separation phase of electrophoresis.
3353. general purpose computer A computer designed to perform, or that is capable of performing, in a reasonably efficient manner, the functions required by both scientific and business…
3354. general purpose network See common user network.
3355. general-purpose system A computer system that is designed to aid in solving a wide variety of problems [TCSEC].
3356. Generation The electricity generated by a system as recorded by a KWH meter, recorded in KWH or MWH.
3357. generation loss In analog recording, cumulative deterioration of signal quality introduced as a consequence of limitations of the recording electronics and storage…
3358. genlock The synchronization of two television signals at the vertical, horizontal, and chroma phase levels such that the signals may be cut, mixed, or cross-faded…
3359. geometric optics The branch of optics that describes light propagation in terms of rays. Note 1: Rays are bent at the interface between two dissimilar media, and may be…
3360. Geometric spreading As the sound moves away from the source, the area that the sound energy covers becomes larger and thus sound intensity decreases.
3361. geostationary orbit A circular orbit in the equatorial plane, any point on which revolves about the Earth in the same direction and with the same period as the Earth's…
3362. Geostationary Satellite A satellite that rotates at the same rate as the earth, remaining over the same spot above the equator.
3363. geostationary satellite orbit The orbit in which a satellite must be placed to be a geostationary satellite. [NTIA] [RR]
3364. geosynchronous orbit Any orbit about the Earth, which orbit has a period equal to the period of rotation of the Earth about its axis, and in the same sense, i.e.
3365. germanium photodiode A germanium-based PN- or PIN-junction photodiode. Note 1: Germanium photodiodes are useful for direct detection of optical wavelengths from approximately…
3366. GETS Abbreviation for Government Emergency Telecommunications Service (GETS).
3367. Ghost See Bit Stream Back-up.
3368. Ghosting This condition occurs when two or more targets reside close to the same plane also containing two sensors viewing the targets so they are within…
3369. GIF Generic Interface.
3370. gigaflop A billion, i.e., 109, floating point operations per second.
3371. gigahertz (GHz) A unit of frequency denoting 109 Hz.
3372. GII Global Information Infrastructure.
3373. Glare The excessive brightness from a direct light source that makes it difficult to see what one wishes to see.
3374. glare master The Signaling System No. 7 (SS7) switch designated as control switch for circuits in the both-way circuit group.
3375. glass In the strict sense, a state of matter. [FAA] 2. In fiber-optic communication, any of a number of noncrystalline, amorphous inorganic substances, formed…
3376. glide slope facility In aeronautical navigation, an instrument approach landing facility that furnishes vertical guidance information to an aircraft from its approach altitude…
3377. global Something you can see from anywhere, usually used of variables and subroutines that are visible everywhere in your program.
3378. global address In a communications network, the predefined address that is used as an address for all users of that network, and that may not be the address of an…
3379. global area network (GAN) A network that (a) is composed of different interconnected computer networks and (b) covers an unlimited geographical area.
3380. global functional plane (GFP) The plane in the intelligent network conceptual model that defines service independent building blocks (SIBs) used in providing service features. [T1.
3381. global information infrastructure See GII.
3382. Global Positioning System (GPS) (GPS) A navigation system which uses a constellation of artificial earth satellites to make precise determinations of the latitude and longitude of locations on…
3383. global security environment A security domain in a System Security policy. The GSE is the general security environment in which the system is located.
3384. global status The set of attributes of an entity, described at a particular time, when that set is extended to every occurrence of that entity within a prescribed…
3385. global system for mobile communications (GSM) A public, all-digital cellular network that is standardized worldwide and that uses (a) TDMA techniques for multiplexing at approximately 900 MHz, (b)…
3386. global title (GT) A "logical" or "virtual" address used for routing Signaling System No. 7 (SS7) messages using signaling connection control part (SCCP) capabilities.
3387. glyph Any graphic symbol not in the ASCII character set. [After IS 14651]
3388. GMT Greenwich Mean Time (now known as Universal Coordinated Time)
3389. go list Synonyms bookmark list, history list, hotlist.
3390. go-ahead message Synonym go-ahead notice.
3391. go-ahead notice In a tape-relay communications system, a service message, usually sent to a relay station or to a tributary station, that contains a request to the…
3392. go-ahead tone In communications systems, an audible signal transmitted by a system indicating that the system is ready to receive a message or signal. [From Weik '89]
3393. gold code In spread-spectrum systems, a code that is generated by summing, using modulo-two addition, the outputs of two spread-spectrum code-sequence generators.
3394. Gopher A menu-based information searching tool that allows users to access various types of databases, such as FTP archives and white pages databases.
3395. gopherspace That part of the cyberspace to which the user has access by means of gopher software. [2382-pt.
3396. GOS Abbreviation for grade of service.
3397. GOSIP Government Open Systems Interconnect Profile (CALS term).
3398. Government Emergency Telecommunications Service (GETS) A special federal government telecommunications service that provides National Security and Emergency Preparedness (NS/EP) users with priority switched…
3399. Government Open Systems Interconnection Profile See GOSIP.
3400. GPI Abbreviation for general purpose interface. An equipment-interface device (usually computer equipment) with some number of digital lines, usually a…