Telecommunications terms starting with S

935 terms

S 1) South or 2) Snow
S interface For basic rate access in an Integrated Services Digital Network (ISDN) environment, a user-to-network interface reference point that (a) is characterized…
S reference point The conceptual reference point dividing the TEI (terminal endpoint identifier) and the NT2 (network termination 2) in a particular ISDN access arrangement.
S-F Abbreviation for store-and-forward.
safeguarding statement [A] statement affixed to a computer output or printout that states the highest classification being processed at the time the product was produced and…
safety service Any radiocommunication service used permanently or temporarily for the safeguarding of human life and property. [NTIA] [RR]
sample key Key intended for off-the-air demonstration use only. [INFOSEC-99]
sampled data Data in which the information content exists only for instantaneous values measured or determined at or for discrete intervals.
sampling The process of digitizing analog information to identify relevant information.
sampling frequency The rate at which sensor data is read or sampled.
sampling interval The reciprocal of the sampling rate, i.e., the interval between corresponding points on two successive sampling pulses of the sampling signal.
Sampling Rate The frequency at which analog signals are converted to digital values during digitization. The higher the rate, the more accurate the process.
sampling theorem Synonym Nyquist's theorem.
sanitize [In INFOSEC, the] process to remove information from media such that data recovery is not possible.
sanitizing Of a recording medium, erasing or overwriting all data in such a manner that it cannot be recovered, even by extraordinary, e.g., laboratory, means.
SAP Fluid content of the xylem and phloem cells of plants. Fluid content of the vacuole generally referred to as cell sap.
satellite A chromosomal segment that branches off from the rest of the chromosome but is still connected by a thin filament or stalk.
satellite access In satellite communications systems, the establishment of contact with a communications satellite space station.
satellite communications A telecommunications service provided via one or more satellite relays and their associated uplinks and downlinks.
satellite digital audio radio service (SDARS) A satellite-based direct-broadcast radio service in which digitally encoded audio entertainment material is broadcast to Earth-based receivers, either…
satellite Earth terminal Synonym Earth terminal.
satellite emergency position-indicating radiobeacon An Earth station in the mobile-satellite service the emissions of which are intended to facilitate search and rescue operations. [RR]
Satellite Home Viewer Improvement Act Of 1999 (SHVIA) An Act modifying the Satellite Home Viewer Act of 1988, SHVIA permits satellite companies to provide local broadcast TV signals to all subscribers who…
satellite link A radio link between a transmitting Earth station and a receiving Earth station through one satellite.
Satellite Master Antenna Television (SMATV) A satellite dish system used to deliver signals to multiple dwelling units (e.g., apartment buildings and trailer parks).
satellite network A satellite system or a part of a satellite system, consisting of only one satellite and the cooperating Earth stations. [RR] 2.
satellite operation See satellite PBX.
satellite PBX A PBX system that is not equipped with attendant positions, and is associated with an attended main PBX system.
satellite period See period (of a satellite).
satellite relay An active or passive satellite repeater that relays signals between two terminals.
satellite system A space system using one or more artificial Earth satellites. [NTIA] [RR] [47CFR]
Saturation Saturation The condition in which the partial pressure of any fluid constituent (water in the atmospheric air) is equal to its maximum possible partial…
Scalability The capacity of a system to expand without requiring major reconfiguration or re-entry of data.
scan A picture of structures inside the body. Scans often used in diagnosing, staging, and monitoring disease include liver scans, bone scans, and computed…
scan line The line produced on a recording medium frame by a single sweep of a scanner. [JP1] 2. Synonym scanning line.
scan-stop lockup In automatic link establishment (ALE) radios, the undesired condition in which the normal process of (a) scanning radio channels, (b) stopping on the…
scanner In medicine, an instrument that takes pictures of the inside of the body.
Scanning Scanning is the process of converting a hard copy paper document into a digital image for use in a computer system.
scanning direction In facsimile transmitting equipment, the scanning of an object, such as a message surface or the developed plane in the case of a drum, along parallel…
scanning field In facsimile systems, the total of the areas that are actually explored by the scanning spot during the scanning of the object by the transmitter or…
scanning line In an imaging system, the path traversed by a scanning spot during a single line sweep.
scanning line frequency In facsimile, the frequency at which a fixed line perpendicular to the direction of scanning is crossed by a scanning spot.
scanning line length In facsimile systems, the total length of a scanning line, equal to the spot speed divided by the scanning line frequency.
scanning line period In facsimile systems, the time interval between (a) the instant at which the scanning spot probes or writes to a given spot on one scanning line, and (b)…
scanning line rate Synonym scanning line frequency.
scanning pitch The distance between the centers of consecutive scanning lines.
scanning rate In facsimile and television systems, the rate of displacement of the scanning spot along the scanning line.
scanning spot In facsimile systems, the area on the object, i.e., the original, covered instantaneously by the pickup system of the scanner.
Scatter When refering to photons and light, scattering describes the phenomenon of a source absorbing, and then emanating light in all directions.
Scattering The process in which a beam of light is diffused or deflected by collisions with particles suspended in the atmosphere.
scattering center In the microstructure of a transmission medium, a site at which electromagnetic waves are scattered.
scattering coefficient The factor that expresses the attenuation caused by scattering, e.g., of radiant or acoustic energy, during its passage through a medium.
scattering cross section The area of an incident wavefront, at a reflecting surface or medium, such as an object in space, through which will pass radiant energy, that, if…
scattering loss The part of the transmission (power) loss that results from scattering within a transmission medium or from roughness of a reflecting surface.
scavenge To search, without authorization, through residual data to acquire sensitive information. [2382-pt.8]
scavenging Searching through object residue to acquire data. [INFOSEC-99]
SCC (1) Standing Consultative Commission (Treaty negotiation related term). (2) Space Control Center. 258
Scene an area, object, or person external to the examining forensic laboratory facility, from which evidence is identified, documented, collected, and/or…
scene cut Video imagery in which consecutive frames are highly uncorrelated.
scene cut response In video systems, the perceived impairments associated with a scene cut.
schematic A diagram, drawing, or sketch that details the elements of a system, such as the elements of an electrical circuit or the elements of a logic diagram for…
scintillation In electromagnetic wave propagation, a small random fluctuation of the received field strength about its mean value.
scrambler A device that transposes or inverts signals or otherwise encodes a message at the transmitter to make the message unintelligible at a receiver not…
scratch pad store (SPS) Temporary key storage in crypto-equipment. [INFOSEC-99]
scream Synonym bang.
screen A screen is a set of criteria against which you measure stocks or other investments to find those that meet your criteria.
screen capture In computers, the process or act by which the data currently displayed on a monitor, usually representing a single frame of information, are stored or…
screened subnetwork A subnetwork that permits access from both untrusted external networks and from trusted internal networks, but does not permit traffic flow between the…
screened-host gateway Synonym bastion host.
screening router A network router capable of discriminating network-based traffic on the protocol type and the value of the protocol fields within the packet. [2382-pt.35]
script A text "file" that is a program intended to be executed directly rather than compiled to another form of file before execution.
scripting language A programming language designed specifically for Web site programming. Examples include JScript and Microsoft Visual Basic Scripting Edition (VBScript).
scroll In a display device, to move the display window of the screen vertically to view the contents of a stored document.
scroll-mode terminal A terminal in which the data are displayed (or pass by) a line at a time.
SCSI Small Computer Systems Interface.
SDARS See satellite digital audio radio service.
SDLC Synchronous Data Link Control ( TelComm /Computer term).
Seal To mark a document with a seal; to authenticate or make binding by affixing a seal. Court seal, corporate seal.
Search Engine A program that enables search for keywords or phrases, such as on web pages throughout the World Wide Web.
search robot See bot, droid.
search time In data processing systems, the time interval required to locate a particular data element, record, or file in a storage device.
SECAM Acronym for système electronique couleur avec memoire. A television signal standard (625 lines, 50 Hz, 220 V primary power) used in France, eastern…
second (s) In the International System of Units (SI), the time interval equal to 9,192,631,770 periods of the radiation corresponding to the transition between the…
second dialtone Dialtone presented to the call originator after an access code has been dialed for access to a second, outside, telecommunications system or service. 2.
second window Of silica-based optical fibers, the transmission window at approximately 1.3 m.
secondary channel In a system in which two channels share a common interface, a channel that has a lower data signaling rate (DSR) capacity than the primary channel.
secondary emission Particles or radiation, such as photons, Compton recoil electrons, delta rays, secondary cosmic rays, and secondary electrons, that are produced by the…
secondary frequency standard A frequency standard that does not have inherent accuracy, and therefore must be calibrated against a primary frequency standard.
secondary radar A radiodetermination system based on the comparison of reference signals with radio signals retransmitted from the position to be determined.
secondary radiation See secondary emission.
secondary service area [T]he service area of a broadcast station served by the skywave and not subject to objectionable interference and in which the signal is subject to…
Secondary Station A station that has been selected to receive a transmission from the primary station.
secondary surveillance radar Synonym secondary radar.
secondary time standard A time standard that requires periodic calibration against a primary time standard.
SECORD Acronym for secure voice cord board. A desk-mounted patch panel that provides the capability for controlling (a) sixteen 50-kb/s wideband or sixteen…
Secret Key A cryptographic key that is used with a secret key (symmetric) cryptographic algorithm, that is uniquely associated with one or more entities and is not…
secret key encryption Any encryption process that (a) depends on only one encryption key, known only to message senders and receivers, and (b) is used to both encode and decode…
SECTEL Acronym for secure telephone. See STU.
section An area equal to 640 acres or 1 square mile.
section boundary The boundary that separates a network section from the adjacent circuit section, or separates an access circuit section from the adjacent DTE (data…