Telecommunications — page 30 of 85

8,405 terms including subtopics (8,400 terms filed directly here)

Subtopics

Telecommunications terms

  1. explicit services Services that can be accessed from an application program, via an API, and are generally provided only when requested [POSIX.0].
  2. exploder Synonym mail exploder.
  3. exploitable channel 1. [A] Channel that allows the violation of the security policy governing an information system (IS) and is usable or detectable by subjects external to…
  4. exposed facilities Any outside plant facilities subject to the effects of lightning; or to power contacts, power induction, or differences in ground potential any of which…
  5. exposure Contact of an organism with a chemical, radiological, or physical agent.
  6. express orderwire A permanently connected voice circuit between selected stations for technical control purposes.
  7. extended ACL An optional directory access control feature available for an IBM® Lotus® Domino™ Directory and Extended Directory Catalog used to apply restrictions…
  8. extended area service (EAS) A network-provided service feature in which a user pays a higher flat rate to obtain wider geographical coverage without paying per-call charges for calls…
  9. extended binary coded decimal interchange code See EBCDIC.
  10. extended superframe (ESF) In T-carrier, a synchronization frame that delineates 24 DS1 frames Note: ESF requires less frequent synchronization than the T-carrier D-4 superframe…
  11. extended-definition television (EDTV) Television in which (a) improvements are made to the standard National Television System Committee (NTSC) television system, (b) the improvements are…
  12. extensibility A property of a system, format, or standard that allows changes in performance or format within a common framework, while retaining partial or complete…
  13. Extensible Markup Language See XML.
  14. extension bell In telephony, a user end device, separate from a subscriber telephone, which device produces an audible signal indicating that there is an incoming call…
  15. extension bit The first bit of each octet of the address field of a packet. The first octet is identified by the extension bit set to 0, and the second octet is…
  16. extension facility A facility that provides access to communications for a user or group of users isolated from a central communications node.
  17. extension terminal A terminal that is added to an existing terminal and that uses the same circuit and address, i.e., port and number, as the terminal to which it is added.
  18. external environment A set of external entities to the application platform with which information is exchanged.
  19. external environment interface (EEI) The interface between the application platform and the external environment across which information is exchanged.
  20. external timing reference In a given communications system, a timing reference obtained from a source, such as a navigation system, external to the given system.
  21. external viewer A plug-in, add-on, or helper application used with a Web browser to present graphics, audio, or video files.
  22. extinction coefficient The sum of the absorption coefficient and the scattering coefficient. [From Weik '89]
  23. extinction ratio (re) The ratio of two optical power levels, of a digital signal generated by an optical source, e.g.
  24. extra bit Synonym added bit.
  25. extra block Synonym added block.
  26. extra sector In information assurance, a sector that is written on a diskette track in excess of the standard number of sectors, as part of a method of copy protection.
  27. extra track In information assurance, a track that is written on a diskette in excess of the standard number of tracks, as part of a method of copy protection.
  28. extraction resistance [The] capability of crypto-equipment or secure telecommunications equipment to resist efforts to extract [the] key. [INFOSEC-99]
  29. extranet An Internet based access method to a corporate intranet site by limited or total access through a security firewall.
  30. extremely high frequency (EHF) Frequencies from 30 GHz to 300 GHz. See electromagnetic spectrum.
  31. Extremely Low Frequency (ELF) (ELF) Refers to a band of frequencies from 30 to 300 Hz.
  32. extrinsic joint loss For an optical fiber, that portion of a joint loss that is not intrinsic to the fibers, e.g.
  33. eye pattern An oscilloscope display in which a pseudorandom digital data signal from a receiver is repetitively sampled and applied to the vertical input, while the…
  34. eyes only A message marker for a special-category message that is intended for delivery only to a specific person, or authorized representative of that person, and…
  35. F layer See F region.
  36. F Region In solar-terrestrial terms, the upper layer of the ionosphere, approximately 120 to 1500 km in altitude.
  37. facet erosion In laser diodes, a phenomenon in which a high field intensity of stimulated optical radiation causes degradation of the facets, i.e.
  38. facility A fixed, mobile, or transportable structure, including (a) all installed electrical and electronic wiring, cabling, and equipment and (b) all supporting…
  39. facility assembly A group of interconnected equipment and transmission media uniquely identified and dedicated to a specific type of service. [T1.238-1994/97]
  40. facility code A two-digit code (FC) used in the exchange-carrier-to-interexchange carrier (EC-to-IC) facility/service selective signaling protocol and the IC-to-EC…
  41. facility grounding system The electrically interconnected system of conductors and conductive elements that (a) provides multiple current paths to the earth electrode subsystem…
  42. facility group The particular group of facilities to route the call. [T1.667-1999]
  43. facility group member The specific member of a trunk group or a multi-line hunt group. [T1.667]
  44. facsimile (FAX) A form of telegraphy for the transmission of fixed images, with or without half-tones, with a view to their reproduction in a permanent form.
  45. facsimile converter In a facsimile receiver, a device that changes the signal modulation from frequency-shift keying (FSK) to amplitude modulation (AM). 2.
  46. facsimile frequency shift At any point in a frequency-shift facsimile system, the numerical difference between the frequency that corresponds to a white signal and the frequency…
  47. facsimile picture signal In facsimile systems, the baseband signal that results from the scanning process.
  48. facsimile receiver In a facsimile system, the equipment that converts the facsimile picture signal into a recorded copy.
  49. facsimile recorder In a facsimile receiver, the device that performs the final conversion of the facsimile picture signal to an image of the object, i.e.
  50. facsimile signal level In a facsimile system, the signal level at any point in the system. Note 1: The facsimile signal level is used to establish the operating levels.
  51. facsimile transceiver In a facsimile system, the equipment that sends and receives facsimile signals.
  52. facsimile transmitter In a facsimile system, the equipment that converts the baseband picture signals, i.e.
  53. Fade this means to cover all or part of the bank bet, also called cover or cover the bank.
  54. fade margin A design allowance that provides for sufficient system gain or sensitivity to accommodate expected fading, for the purpose of ensuring that the required…
  55. fading In a received signal, the variation (with time) of the amplitude or relative phase, or both, of one or more of the frequency components of the signal.
  56. fading distribution The probability distribution that signal fading will exceed a given value relative to a specified reference level.
  57. fading margin Synonym fade margin.
  58. fail See failure, graceful degradation.
  59. fail safe Of a device, the capability to fail without detriment to other devices or danger to personnel. 2.
  60. fail soft [The] selective termination of affected nonessential processing, when hardware or software failure is determined to be imminent. [INFOSEC-99]
  61. fail-safe operation Operation that ensures that a failure of equipment, process, or system does not propagate beyond the immediate environs of the failing entity. 2.
  62. Failure An incident resulting in the uncontrolled release of water from a dam. Destroyed and made useless, ceases to function as a dam.
  63. failure access [An] Unauthorized access to data resulting from a hardware or software failure. [INFOSEC-99]
  64. failure control [The methods] used to detect imminent hardware or software failure and provide fail safe or fail soft recovery. [INFOSEC-99]
  65. fair queuing The controlling of congestion in gateways by restricting every host to an equal share of gateway bandwidth.
  66. fake sector In information assurance, a sector consisting of a header but no data, used in large numbers on a diskette to cause an unauthorized copying program to…
  67. fall time The time required for the amplitude of a pulse to decrease (fall) from a specified value (usually 90 percent of the peak value exclusive of overshoot or…
  68. false character See illegal character.
  69. false clock A condition where a phase-locked loop controlling a clock locks on a frequency other than the correct frequency.
  70. false lock A condition where a phase-locked loop locks to a frequency other than the correct one, or to an improper phase.
  71. fan out The process of splitting a message to deliver e-mail messages to individual recipients. [Exchange 2007]
  72. fan-beam antenna A directional antenna producing a main beam having a large ratio of major to minor dimension at any transverse cross section.
  73. fanout cable Synonym breakout cable.
  74. FAQ file Abbreviation for Frequently Asked Questions file. An online file that contains frequently asked questions with answers provided to assist new users and…
  75. Far Field The region far from an antenna compared to the dimensions of the antenna and the wavelength of the radiation.
  76. far zone Synonym far-field region.
  77. far-end block error (FEBE) An indication returned to a transmitting node (source) that an errored block has been detected at the receiving node (sink). [T1.105-1988]
  78. far-end crosstalk Crosstalk that is propagated in a disturbed channel in the same direction as the propagation of a signal in the disturbing channel.
  79. far-end customer interface An associated, loop signaling, customer installation located at the far end of the network transmission path from the network interface (NI) described in…
  80. far-end receive failure (FERF) An indication returned to a transmitting link terminating equipment (LTE) upon receipt of a line AIS (alarm indication signal) code or detection of an…
  81. far-field diffraction pattern The diffraction pattern of a source (such as an LED, ILD, or the output end of an optical fiber) observed at an infinite distance from the source.
  82. far-field radiation pattern A radiation pattern measured at the far field of an antenna or other emitter.
  83. far-field region The region where the angular field distribution is essentially independent of distance from the source.
  84. Faraday effect A magneto-optic effect in which the polarization plane of an electromagnetic wave is rotated under the influence of a magnetic field parallel to the…
  85. fast packet switching A packet switching technique that increases the throughput by eliminating overhead.
  86. fast select An optional user facility in the virtual call service of CCITT X.25 protocol (now, ITU-T X.
  87. fat client A client-centric computing model where software must be installed on each client in a network.
  88. Fault "Fault" means adultery, alcohol abuse, drug abuse, physical abuse, domestic violence, abandonment or reckless spending.
  89. fault management In network management, the set of functions that (a) detect, isolate, and correct malfunctions in a telecommunications network, (b) compensate for…
  90. fault protection subsystem In a facility power distribution system, the subsystem that provides a direct path from each power sink to the earth electrode subsystem.
  91. Fault-Tolerance The ability of a processor to maintain mission effectiveness after some subsystems failed.
  92. FAX Short for facsimile. A process of transmitting documents by scanning them to digital, converting to analog, transmitting over phone lines and reversing…
  93. FC A product of hydrolysis of an IgG antibody, consisting of parts of the constant regions of two heavy chains held together by a disulphide bridge, but…
  94. FCC Federal Communications Commission.
  95. FCC registration program The Federal Communications Commission program and associated directives intended to assure that all connected terminal equipment and protective circuitry…
  96. FCS Fire Control Section.
  97. FDDI Fiber Distributed Data Interface. An ANSI standard LAN architecture that uses optical fiber cable for high-speed transmission.
  98. FDDI-2 See fiber distributed data interface.
  99. FDHM See full width at half maximum.
  100. FDM Common abbreviation for Financial Disclosure Management, the online program to electronically file and manage financial disclosure reports.

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