A device, usually laser or LED, that emits light energy. [Arr11]
Shared Port Adapter
Length of coaxial cable between amplifiers, usually expressed in equivalent decibels of gain required to overcome cable losses at the highest television channel or frequency carried in the system, such as “22dB spacing”. [Arr11]
Distance between line extenders or distribution amplifiers; also, distance between taps.
The process of designing a DWDM transmission span to achieve the required performance based on fiber type, the transmission distance, amplifier spacing, noise, power, and channel count. [Fib111]
Video interference in a satellite transmitted picture appearing as small black or white dots or blips which may be caused by weak signal reception, poor receiver performance, improper tuning or polarization and possibly an insufficient signal-to-noise ratio. [Arr11]
An antenna configuration of two or more elements that are physically spaced (spatially diverse) to combat signal fading and improve signal quality; the desired spacing depends on the degree of multipath angle spread.
Spatial Division Multiple Access (SDMA)
A complement (not an alternative) to CDMA and TDMA, this technology increases the number of users that can access an existing wireless phone or data system by exploiting the spatial characteristics of the channel itself through highly developed implementation of an intelligent antenna system's capabilities for receiving and transmitting.
Special Effects Generator
A device permitting combinations of images on a television screen supplied by one or more video inputs.
Keycodes other than the Mandatory Ordinary Keycodes that have been reserved for special purposes by special applications such as the monitor application, or some other implementation-dependent application with special privileges, such that they will not be treated the same as the Mandatory Ordinary Keycodes and may not be available to the application that has focus.
The number of data bits per second that can be transmitted in a one Hertz bandwidth range. [Fib111]
A measure of the extent of a spectrum. For a source, the width of wavelengths contained in the output at one half of the wavelength of peak power. Typical spectral widths are 50 to 160 nm for an LED and less than 5 nm for a laser diode. [Fib111]
Spectral Width, Full Width, Half Maximum (FWHM)
The absolute difference between the wavelengths at which the spectral radiant intensity is 50 percent of the maximum power. [Fib111]
Frequencies or radiations that exist in a continuous range and have a common characteristic. A spectrum may be inclusive of many spectrum, e.g., the electromagnetic radiation spectrum includes the light spectrum, radio spectrum, infrared spectrum, etc. [Arr11]. Link to SCTE sponsored primer on RF spectrum and the cable plant: http://www.scte.org/mmpres/Primer/RFSpectrum/index.html
Spectrum Management System (SMS)
A system for managing the radio frequency (RF) cable spectrum.
Service Profile Identifier
A process that can greatly simplify the process of installing an ISDN adapter. Given the regular 10-digit telephone number(s) assigned to an ISDN line, a SPID guessing algorithm tries combining the seven and 10-digit phone numbers with various prefixes and suffixes until it finds it can communicate with the phone company's central office switch. Once it discovers the right combination, the algorithm also can figure out the kind of central office switching system to which the adapter is connected.
Service Provider Information Technology
A permanent connection of two optical fibers. [Arr11]
Excerpt from ANSI/SCTE 87-1 2008,
“Graphic Symbols For Cable Systems Part 1: HFC Symbols”
Fiber Optic Cable Splice Diagram courtesy of Fiber Optic Info, http://www.fiber-optics.info/fiber_optic_glossary/s
Satellite signal that falls on locations outside the beam pattern's defined edge of coverage. [Sat07]
A form of satellite stabilization and attitude control which is achieved through spinning the exterior of the spacecraft about its axis at a fixed rate. [Sat07]
A splice block is used to splice two connectors. [Arr11]
A metal or plastic housing used to enclose and protect fiber splices. Synonym for splice closure. [Arr11]
This connector is used to join together two cables. [Arr11]
See insertion loss.
Flat rectangular components used to secure splices and store excess fiber. [Arr11]
A passive device (one with no active electronic components) which distributes a television signal carried on a cable in two or more paths and sends it to a number of receivers simultaneously. A low noise amplifier (LNA) splitter is an active device capable of distribution of RF signals into two or more paths combined with the ability to provide signal gain and RF power level adjustment.
Excerpt from ANSI/SCTE 87-1 2008,
“Graphic Symbols For Cable Systems Part 1: HFC Symbols”
The ratio of power emerging from two output ports of a coupler. [Fib111]
See self-phase modulation.
Federal law requires cable systems and television stations to delete coverage of local sports events to protect gate receipts.
A focused antenna pattern sent to a limited geographical area. Spot beams are used by domestic satellites to deliver certain transponder signals to geographically well-defined areas such as Hawaii, Alaska and Puerto Rico. [Sat07]
Revenue gained from advertising that is placed on a cable system by a local or national advertiser.
Enables the successful transmission to hostile transmission environments.
Single Program Transport Streams
In telecommunications, squelch is a circuit function that acts to suppress the audio (or video) output of a receiver. It is activated in the absence of a sufficiently strong desired input signal, in order to exclude undesired lower-power input signals that may be present at or near the frequency of the desired signal. (Contrast with noise suppression.) . Two types of selective squelch are commonly used. A continuous tone-coded squelch system (CTCSS) uses any one of about 50 tones from 67 to 254 Hz. Digital-coded squelch (DCS) systems use a continuous stream of digital data to identify themselves, running in the same audio frequency band as the tones but at about 131 baud. CTCSS is usually called PL tone (for "Private Line", a trademark of Motorola), or simply squelch tone. It can be regarded as a form of in-band signaling. See also radiotelephone. Squelch can also be used based strictly on the signal strength of the signal, such as when a television mutes the audio or blanks the video on "empty" channels, or when a walkie talkie mutes the audio when no one is calling. Sources: modified from Federal Standard 1037C and from the NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management in support of MIL-STD-188. [Wor11]
See stimulated Raman scattering.
Signaling System Number 7
Secured Socket Layer
Spread Spectrum Multiple Access; refers to a frequency multiple access or multiplexing technique. [Sat07]
Signal Switching Point
Solid State Power Amplifier; a very large scale integration (VSLI) solid state device that is gradually replacing Traveling Wave Tubes (TWTs) in satellite communications systems because they are lighter weight and are more reliable. [Sat07]
Straight-through fiber optic connector developed by AT&T. [Arr11]
The eight-pin RJ-45 connector on the “back side” of an NT-1 or ISDN adapter that connects one or more ISDN adapters to the NT-1. Of the eight pins on the RJ-45 connector, the outside two pins on each side provide power and the center four form a “transmit” and “receive” pairs. ISDN adapters with built-in NT-1s do not have an S/T Interface.
Stabilized Light Source
An LED or laser diode that emits light with a controlled and constant spectral width, center wavelength, and peak power with respect to time and temperature. [Fib111]
Stacked Antenna Array
Two or more identical off-air antennas aligned and mounted so as to achieve increased gain and to suppress and, in many instances, eliminate ghosts. [Arr11]
This term is used to designate the interval of time, in NVOD; that is, the time between the beginning of a movie or program, on one channel and the beginning of the same program on another channel. (Ex: A movie starts at 7:00 on channel 50, at 7:15 on channel 51, at 7:30 on channel 52-the movie is staggercast 15 minutes.)
Standalone MTA (S-MTA)
A single node that contains an MTA and a non-DOCSIS MAC (e.g., Ethernet).
Standard Broadcast Channel
A specific band of off-air frequencies occupied by a carrier and two side bands of a transmitted signal, with the carrier frequency at the center. [Arr11]
Standby Power Supply
A step down alternating current (AC) trans-former which converts 120 volts AC to a lower AC voltage (30 or 60volts) to be carried on the coaxial cable along with the cable signals to power active devices in the distribution plant. In addition, batteries and an inverter are included to provide backup power in the event of utility power (120 VAC) failure. [Arr11]
A coupler in which power at any input port is distributed to all output ports. [Fib111]
Star Coupler Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/s