Telecommunications — page 69 of 85

Telecommunications terms

6801. service independence Not necessarily specific to one service. [T1.667-1999]
6802. service integrity The degree to which a service is provided without excessive impairment, once obtained. [NATO]
6803. service logic A sequence of processes/functions used to provide a specific service. [T1.667-1999]
6804. service management access function (SMAF) The entity equivalent to the work station function between network operators and/or subscribers and network service management functional entities. [T1.
6805. Service Management Team (SMT) An entity comprised of the Regional Bell Operating Company's (RBOCs) who were ordered by the FCC to administer the SMS/800 at the advent of portability…
6806. service node (SN) A physical entity that contains the service control function, service data function, specialized resource function and service switching/call control…
6807. service outage The state of a service when (a) a network failure impairs or prevents the initiation of new requests for the service, (b) continued use of the service is…
6808. service plan The rate plan you select when choosing a wireless phone service. A service plan typically consists of a monthly base rate for access to the system and a…
6809. service probability The probability of obtaining a specified (or higher) grade of service during a given period of time.
6810. service profile Synonym UPT service profile.
6811. service profile management Synonym UPT service profile management.
6812. service program Synonym utility program.
6813. service provider 1. An organization that provides services for content providers and for users of a computer network .
6814. service routine Synonym utility program.
6815. service signals Signals that enable data systems equipment to function correctly, and possibly to provide ancillary facilities. Synonym housekeeping signals.
6816. service subscriber (SS) An entity that contracts for services offered by service providers. [T1.667-1999]
6817. service switching and control point (SSCP) A physical entity that contains the service control function, service data function and the service switching/call control functions. [T1.667-1999]
6818. service switching function (SSF) The set of processes that provide for interaction between a call control function and a service control function. [T1.667-1999]
6819. service switching point (SSP) A physical entity that implements a service switching function. [T1.667-1999]
6820. service termination point The last point of service rendered by a commercial carrier under applicable tariffs.
6821. service user An individual or organization, including a service vendor, that is provided a telecommunications service for which a priority level has been requested or…
6822. service-provider portability A faculty that allows an end user to retain the same directory number after changing from one service provider to another. [After T1.708-1998]
6823. serving area ID Information that identifies the local serving area where the network provider operates. [After T1.667-1999]
6824. session key An encryption key that provides privacy during a call and may be changed dynamically by the system. [T1.Rpt22-1993]
6825. Session Layer See Open Systems Interconnection--Reference Model.
6826. Set Three of a kind when you have two of the rank in your hand, and there is one on the board.
6827. set-top Referring to an auxiliary device that usually rests on top of or adjacent to a television receiver and that is used in direct analog or digital satellite…
6828. set-top box Synonyms set-top, set-top converter.
6829. seven-bit byte Synonym septet.
6830. seven-hundred (700) service A personal telephone service that allows individuals to receive, via a single number, telephone calls in various locations (e.g.
6831. severely errored second (SES) A one-second period that contains >30% errored blocks or at least one severely disturbed period.
6832. severely errored unit of time 1. A specified period of time, during which bits are transferred from a source to a destination, where 30% of the blocks received are errored, or at least…
6833. sexadecimal Synonym hexadecimal.
6834. sextet A byte composed of six binary elements. Synonym six-bit byte.
6835. SF a type of form designation such as Form SF51, meaning a Standard Form used throughout the Federal Government
6836. SFTS Abbreviation for standard frequency and time signal. See standard time and frequency signal service.
6837. SGML Standard Generalized Markup Language (Computer term).
6838. shadow In secure systems, a permutation of the bits in a byte or other data unit, which permutation is used to increase redundancy during the signature process.
6839. shadow loss The attenuation caused to a radio signal by obstructions in the propagation path. 2.
6840. shannon (Sh) The unit of information derived from the occurrence of one of two equiprobable, mutually exclusive, and exhaustive events.
6841. Shannon's law A statement defining the theoretical maximum rate at which error-free digits can be transmitted over a bandwidth-limited channel in the presence of noise…
6842. shaping network A network inserted in a circuit for the purpose of improving or modifying the waveform of signals.
6843. shared service link connection A service link connection that can be used by any service customer (SC) in a predefined set of SCs on a first-come, first-service-basis; that is, during a…
6844. shareware Software available for downloading from public networks and bulletin board systems, usually at little cost.
6845. sharpness The informal, subjective evaluation of detail in the clarity or resolution seen in an image.
6846. sheath Of a communications or power cable, the outer covering or coverings of tough material, often plastic, that is resistant to environmental hazards such as…
6847. sheath kilometers The actual length of cable in route kilometers. [47 CFR Pt.36-A]
6848. sheath miles The actual length of cable in route miles. [47CFR]
6849. shell See shoulder.
6850. SHF Super High Frequency.
6851. SHIELD Shield (screen) A screen to shield a rain-gauge from the influence of the wind, or to shield a thermometer against insolation.
6852. shielded enclosure [A] room or container designed to attenuate electromagnetic radiation. [INFOSEC-99]
6853. shielded pair A 2-wire transmission line surrounded by a sheath of conductive material that protects it from the effects of external fields and confines fields produced…
6854. shielded twisted pair A transmission line composed of a twisted 2-wire metallic transmission line surrounded by a sheath of conductive material that protects it from the…
6855. Shielding A protective barrier, usually a dense material, which reduces the passage of radiation from radioactive materials to the surroundings.
6856. shielding effectiveness The factor that expresses the attenuation caused by scattering, e.g., of radiant or acoustic energy, during its passage through a medium.
6857. shift The movement of some or all of the characters or bits of a word by the same number of character or bit positions in the direction of a specified end of a…
6858. shift register A storage device, usually in a central processing unit (CPU), in which device a serially ordered set of data may be moved, as a unit, into a discrete…
6859. ship Earth station A mobile Earth station in the maritime mobile-satellite service located on board ship. [NTIA] [RR]
6860. ship station A mobile station in the maritime mobile service located on board a vessel which is not permanently moored, other than a survival craft station. [NTIA] [RR]
6861. ship's emergency transmitter A ship's transmitter to be used exclusively on a distress frequency for distress, urgency or safety purposes. [NTIA] [RR]
6862. shock excitation Synonym impulse excitation.
6863. shock spectrum Synonym response spectrum.
6864. shopping basket In electronic commerce (also called "e-commerce"), an application allowing users of a commercial Web site to select products from the screen display as…
6865. Short Circuit Test Line The term "Short Circuit Test Line" denotes an arrangement in an end office which provides for an ac short circuit termination of a trunk or line by means…
6866. short haul toll traffic A general term applied to message toll traffic between nearby points. In common usage, this term is ordinarily applied to message toll traffic between…
6867. short interruption event (SIE) An event beginning with the occurrence of a bit error ratio (BER) of 10-2 or worse, continuously for each of three or more consecutive seconds, which can…
6868. short message service (SMS) A service in GSM mobile telephony systems that allows the user to send and receive short (maximum 160-character) messages independently of voice calls; a…
6869. short wavelength In optical communication, optical radiation having a wavelength less than approximately 1 m.
6870. Shortwave Also known as Shortwave Trough; a disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it.
6871. shot noise The noise caused by random fluctuations in the motion of charge carriers in a conductor.
6872. SI Special Intelligence.
6873. SID See definition for: security ID (SID)
6874. side circuit Either of the two circuits used to derive a phantom circuit.
6875. side effect An effect of a drug, chemical, or other medicine that is in addition to its intended effect, especially an effect that is harmful or unpleasant.
6876. side lobe In a directional antenna radiation pattern, a lobe in any direction other than that of the main lobe.
6877. sideband In amplitude modulation (AM), a band of frequencies higher than or lower than the carrier frequency, containing energy as a result of the modulation…
6878. sideband transmission See single-sideband transmission.
6879. sidetone The sound of the speaker's own voice (and background noise) as heard in the speaker's telephone receiver.
6880. SIG Abbreviation for special interest group. 1. Within a given technical discipline or area of knowledge, a circle of individuals or organizations having an…
6881. SIGINT Signal Intelligence.
6882. signal A bolt out of the blue; that is, an event triggered by the "operating system", probably when you're least expecting it.
6883. signal center A combination of signal communication facilities operated by the Army in the field and consisting of a communications center, telephone switching central…
6884. signal compression In analog (usually audio) systems, reduction of the dynamic range of a signal by controlling it as a function of the inverse relationship of its…
6885. signal contrast In facsimile, the ratio of the level of the white signal to the level of the black signal. Note: Signal contrast is usually expressed in dB.
6886. signal conversion equipment Synonym modem.
6887. signal distance A measure of the difference between a given signal and a reference signal. Note: For analog signals, the signal distance is the root mean square…
6888. signal distortion See distortion.
6889. signal droop In an otherwise essentially flat-topped rectangular pulse, distortion characterized by a decline of the pulse top.
6890. signal duration A multifrequency (MF) or dual-tone multifrequency (DTMF) signal timing interval during which the signal is being transmitted.
6891. signal element A part of a signal, distinguished by its nature, magnitude, duration, transition, or relative position.
6892. signal expansion Restoration of the dynamic range of a compressed signal.
6893. signal frequency shift See frequency shift.
6894. signal intelligence See signals intelligence.
6895. signal level In a communications system, the signal power or intensity at a specified point and with respect to a specified reference level, e.g., 1 mW.
6896. signal message In communications systems, a message, i.e., an assembly of signaling information, that (a) includes associated message alignment and service indications…
6897. signal processing The processing--such as detection, shaping, converting, coding, and time positioning--of signals, that results in their transformation into other forms…
6898. signal processing gain The ratio of (a) the signal-to-noise ratio of a processed signal to (b) the signal-to-noise ratio of the unprocessed signal.
6899. signal reference subsystem The portion of a facility grounding system that (a) provides reference planes, such as ground-return circuits, for all of the signal paths in the facility…
6900. signal regeneration Signal processing that restores a signal so that it conforms to its original characteristics.