A concentrator that offers one attachment to the FDDI network. [Fib111]
Single Channel Amplifier
A narrow-band amplifier which is tuned to boost the signal strength of one particular television channel. [Arr11]
A method used to transmit a large number of signals over a single satellite transponder. [Sat07]
See single-longitudinal mode laser.
Single-longitudinal Mode Laser (SLM)
An injection laser diode which has a single dominant longitudinal mode. A single-mode laser with a side mode suppression ratio (SMSR) < 25 dB. [Fib111]
SLM Graph of Relative Output versus Wavelength courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s
Single-Mode Fiber (SMF)
An optical waveguide through which only one mode will propagate. Single-mode waveguide is produced by reducing the diameter of the core of the waveguide to 2 to 10 microns. The diameter of the core is dependent on the difference in the refractive index of the core and cladding. As the difference in the refractive index of the core and cladding decreases, the diameter of the core increases. Theoretically, the core could be infinitely large as the difference in index become infinitely small. Single-mode operation is desirable because all modes except the lowest and simplest mode are excluded. This reduces time distortion of signals propagating in unwanted modes, retains phase relationships, and reduces dispersion to the lowest possible value. [Arr11]
Single-mode Optical Loss Test Set (SMOLTS)
An optical loss test set for use with single-mode fiber. [Fib111]
Single Sideband (SSB)
A form of amplitude modulation (AM) whereby one of the sidebands and the AM carrier are suppressed. [Sat07]
Session Initiation Protocol
An adjustment that compensates for slight variance in angle between identical senses of polarity generated by two or more satellites. [Sat07]
The angle at which photoelectric sensors are aligned to prevent light from being reflected back to the sensor from the object during retroreflective sensing; also, the angle a measured part is positioned away from the coordinate system of the measuring instrument. [Pho11]
The behavior whereby electricity migrates to the outside wall of a wire. Link to an SCTE sponsored primer on skin effect: http://www.scte.org/mmpres/Primer/SkinEffect/index.html
A filter designed to decrease the luminosity of the sky without decreasing that of the landscape in the foreground. A filter that has a depth of tint that decreases from top to bottom is used in black and white photography, while a neutral density filter is used in color applications. [Pho11]
Slab Dielectric Waveguide
A waveguide with a rectangular cross section that is composed entirely of dielectric materials. [Pho11]
Solid-state laser geometry in which the standard rod is replaced by a slab of laser material. Often called total-internal-reflection face-pumped laser (TIR-FPL). [Pho11]
The length of the path between a communications satellite and an associated earth station. [Sat07]
See surface-emitting diode.
An aperture, usually rectangular in shape, with a large length-to-width ratio, and a fixed or adjustable shape through which radiation enters or leaves an instrument. The aperture is generally small as compared to the light source. [Pho11]
See single-longitudinal mode laser.
The difference between signal levels at the highest frequency and at the lowest frequency in a cable system. Also called spectrum tilt. [Arr11]
The action of a slope-compensated gain control, whereby slope of amplifier equalization is simultaneously changed with the gain so as to provide the correct cable equalization for different lengths of cable; normally specified by range and tolerance.
Slope Efficiency (SE)
The mean value of the incremental change in optical power for an incremental change in forward current when the device is operating in the lasing region of the optical power output versus forward current curve. Also referred to as differential efficiency. [Fib111]
That longitudinal position in the geosynchronous orbit into which a communications satellite is "parked". Above the United States, communications satellites are typically positioned in slots which are based at two to three degree intervals. [Sat07]
A television system that uses a slow rate of horizontal scanning to increase its reproduction and transmittance accuracy of printed matter, photographs and illustrations. [Pho11]
A threaded type of optical connector. One of the earliest optical connectors to be widely used. Offers poor repeatability and performance. [Fib111] Amphenol developed the SMA from the "Subminiature A" hence SMA, microwave connector. The model 905 had a machined ferrule exactly 1/8 inch in diameter that mated in a machined adapter. When the adapters were not precise enough for better fibers, a necked-down ferrule that mated with a Delrin adapter for better insertion loss performance was offered. Optical SMA connectors are still in use on some military and industrial systems. [Fib05]
Photograph of Optical SMA Connectors courtesy of The Fiber Optic Association, http://www.thefoa.org/tech/connID.htm
Small Office/Home Office (SOHO)
An industry term used to refer to a telecommunications market segment comprised of people working out of their homes or small offices.
Also smart skins. Materials containing sensors (fiber optic or other types) to measure their properties during fabrication and use. [Fib111]
Satellite Master Antenna Television System; The adding of an earth station to a MATV system to receive satellite programs. [Sat07]
A term used to describe a picture condition in which objects appear to be extended horizontally beyond their normal boundaries in a blurred or “smeared” manner.
Surface-Mount Device; see SMT. [Fib111]
Subscriber Media Gateway
Society for Motion Picture and Television Engineers
Television standard, written by the Society of Motion Picture and Television Engineers (SMPTE), that describes a serial digital interface (SDI) for 10-bit 4:2:2 component and 4fsc composite digital transport. [Fib111]
Television standard, written by the Society of Motion Picture and Television Engineers (SMPTE), that describes a synchronous serial interface for MPEG-2 digital transport streams. [Fib111]
Spectrum Management System
Surface Mount Technology
Standalone Multimedia Terminal Adapter
Simple Mail Transfer Protocol
Systems Network Architecture
Subnetwork Access Protocol
Satellite News Gathering; usually with a transportable uplink truck. Sometimes referred to as a “SNG van” or “SNG truck”. [Sat07]
Simple Network Management Protocol
Heavy random noise displayed on a video or television monitor.
System On A Chip
Selectable Output Control
Society for Cable Telecommunications Engineers (SCTE)
A non-profit professional organization serving the cable industry by providing training, certification and standards.
Society for Motion Picture and TV Engineers (SMPTE)
A professional society for motion picture and TV engineers with more than 9,000 members worldwide. It prepares standards and documentation for TV production. SMPTE time code records hours, minutes, seconds and frames on audio or videotape for synchronization purposes.
Programming and programming materials such as films, videotapes, and slides.
Small Office/Home Office
Silicon on Insulator; a semiconductor manufacturing technology in which thin films of single-crystalline silicon are grown over an electrically insulating substrate. [Ans11] Read more: http://www.answers.com/topic/silicon-on-insulator#ixzz1H3em0Nwk
Solar outages occur when an antenna is looking at a satellite, and the sun passes behind or near the satellite and within the field of view of the antenna. This field of view is usually wider than the beamwidth. Solar outages can be exactly predicted as to the timing for each site. [Sat07]
A term taken from physics, used interchangeably with the word transistorized; also includes other semiconductor elements, such as diodes. Generally refers to non-vacuum tube equipment.
An optical pulse having a shape, spectral content, and power level designed to take advantage of nonlinear effects in an optical fiber waveguide, for the purpose of essentially negating dispersion over long distances. [Fib111]
Synchronous Optical NETwork. A worldwide standard of digital communication utilizing optical interfaces. [Arr11]
Silicon on Sapphire; a hetero-epitaxial process that consists of a thin layer of silicon grown on a sapphire (Al2O3) wafer. SOS is part of the Silicon on Insulator (SOI) family of CMOS technologies. SOS is primarily used in military and space applications because of its inherent resistance to radiation. SOS has seen little commercial use to date because of difficulties in fabricating the very small transistors used in modern high-density applications. This drawback is because the SOS process results in the formation of dislocations from crystal lattice disparities between the sapphire and silicon. [Wor11]
The acronym “SOT” refers to “Small Outline Transistor” and is a JEDEC standard class of packaged electronic device. SOT-115J is not an official JEDEC package designation. Philips Semiconductor coined the designation “SOT-115J” in the 1990s to define the cable industry’s in-use since 1968 CATV hybrid amplifier module package outline and dimensions. The “SOT-115J” is neither small nor merely a transistor. Below is a dimensioned package outline drawing of the SOT-115J package (courtesy of RFMD). Link to RFMD website: http://www.rfmd.com/products/BroadbandTransmission/default.aspx