Computation of the tristimulus values of colors in terms of one set of primaries. Note: This computation may be performed electrically in a color television system. [IEEE] [After SMPTE] [ATI11]
In color television technology, of a receiver, the circuitry that separates the chroma information from the video (gray-scale) information and processes the former into its constituent signal components. [ATI11]
Color Difference Signal
The chrominance vectors carrying the color information in a composite format. Note: The color-difference signals have been defined by the ITU-R for existing television systems. [ATI11]
In color television technology, the instantaneous phase of the chroma signal with respect to that of the color burst signal. Note: The phase of the chroma signal at any given instant determines the color balance of the video signal at that instant. [ATI11]
In NTSC color, the carrier whose modulation sidebands are added to the monochrome signal to convey color information, i.e., 3.6 MHz (3.579545 MHz).
Of an electromagnetic source, especially in the optical regime, the hue or wavelength (spectral content) expressed or specified as the hypothetical wavelength(s) emitted by an ideal blackbody having an absolute temperature of n Kelvins (n K). Note 1: Higher numbers indicate hues in or toward the blue; lower numbers indicate hues in or toward the red. Note 2: Examples of color temperature are approximately 5000 K to 5500 K (daylight), approximately 4100 K (fluorescent lighting), and approximately 2800 K (incandescent). Note 3: Color temperature is commonly used to characterize ambient lighting or lighting employed for photographic purposes. [JSB/FAA] [ATI11]
Measurement of colors based on a set of conventions. [After SMPTE] Also, the science of, or body of techniques employed in, (a) the measurement or characterization of color, and (b) the interpretation of the results. Note: Human perception of color is a subjective phenomenon resulting from and dependent upon the properties of the eye and the brain. [ATI11]
A signal combining network that allows several discrete inputs to be added into a common bandwidth and that has high isolation between inputs. Also may refer to a power combining network.
A passive network that permits the addition of several signals into one combined output with a high degree of isolation between individual inputs. It may be a power or frequency combiner.
Any point-to-point communications relay service available to the general public at non-discriminatory rates. The carrier cannot control message content (e.g., telephone companies).
Common Path Distortion (CPD)
The interference of return path signaling caused by the forward path.
Some interferometers use a common beam path but different polarizations for the two beams. This has the advantage that fluctuations of the geometric path length do not affect the interferometer output, whereas the interferometer can be a sensitive detector for birefringence. [Enc11]
An electronic retransmission vehicle located in space in a fixed earth orbit. Signals are transmitted to the satellite from earth station antenna, amplified and sent back to earth for reception by other earth station antennas.
A dedicated standalone system that manages communications activities for other computers.
A noise-reduction technique that applies single compression at the transmitter and complementary expansion at the receiver. [Sat07]
Competitive Local Exchange Carrier (CLEC)
An alternative local telephone company that competes against incumbent Local Exchange Carriers (LECs) for local and access business. Also known as a Competitive Access Provider (CAP) or Alternate Local Telephone (ALT) company. Companies that build high-bandwidth fiber-optic networks to compete with the incumbent telephone and cable operators. See also Overbuilder.
1. With respect to additive mixing, any pair of colors that are radially opposite one another relative to the white point on a chromaticity chart, e.g., the familiar CIE chart. Note: Complementary colors may be combined additively to produce the perception of white. 2. Analogous pairs of colors with respect to subtractive mixing. [ATI11]
The unclamped and unfiltered output of the satellite receiver's demodulator circuit, containing the video information as well as all transmitted subcarriers. [Sat07]
Composite Baseband Signal
The complete audio and video signal without a carrier wave. NTSC video baseband is from zero to 4.2 MHz.[Arr11]
Composite Second Order Beat (CSO)
The peak of the average level of distortion products due to second-order non- linearities in cable system equipment.
A signal consisting of horizontal sync pulses, vertical sync pulses, and equalizing pulses only, with a no-signal reference level. [Fib111]
Composite Triple Beat (CTB)
The peak of the average level of distortion components due to third-order non- linearities in cable system equipment.
Composite Video Signal
The complete video signal. For monochrome, it consists of the picture signal and the blanking and synchronizing signals. For color, additional color synchronizing signals and color picture information are added.
A method for compacting the digital representation of a signal for more efficient transmission or storage.
Software that allows codecs to reduce the number of bits required for data storage or transmission. [Sat07]
Legislation requiring copyright holders to license users of copyrighted material (cable television operators) on a uniform basis and for a stipulated fee.
The Communications Satellite Corporation (part of Lockheed Martin) which serves as the U.S. Signatory to INTELSAT and INMARSAT. [Sat07]
The process of connecting pieces of fiber together. [Fib111]
1) A functional unit that permits a common path to handle more data sources than channels currently available within the path. Usually provides communication capability between many low-speed, asynchronous channels and one or more high-speed, synchronous channels. 2) A device that connects a number of circuits, which are not all used at once, to a smaller group of circuits for economy. [Fib111]
In fiber optic cable, the measurement of how well-centered the core is within the cladding. [Fib111]
Concentricity Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c
Conditional Access (CA) and Encryption
A system that provides selective access to programming to individual customers in exchange for payment.
A material suitable for carrying an electric current.[Arr11]
A pipe or tube, of tile, asbestos-cement, plastic or steel, which is placed underground to form ducts through which cable can be passed.[Arr11]
A way to ensure that information is not disclosed to anyone other than the intended parties. Information is encrypted to provide confidentiality. Also known as privacy.
This is a type of packet-switched network in which no logical connection is required between sending and receiving stations. Each data unit or packet includes the source and destination addresses and can take any available route between source and destination. The Internet Protocol (IP) is connectionless.
Any device for making a temporary or semi-permanent connection.[Arr11]
The maximum value in dB of the difference in insertion loss between mating optical connectors (e.g., with remating, temperature cycling, etc.). Also called optical connector variation. [Fib111]
Constant Bit Rate (CBR)
A service class intended for real-time applications, or those requiring tightly constrained delay and delay variation, as would be appropriate for voice and video applications. The constant availability of a fixed quantity of bandwidth is considered appropriate for CBR service.
Any interference that increases amplitude of the resultant signal. For example, when the wave forms are in phase, they can create a resultant wave equal to the sum of multiple light waves. [Fib111]
Constructive Interference Illustration courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c
The optical signal loss that occurs due to the inability of optical signals to pass through contamination particles (e.g. dirt) in an optical connector. A key potential source of contamination for the fiber connection is oil that is transferred from fingers to the surface of the connector. The diagram below shows how dirt particles (contamination) in an optical connector can cause insertion loss. This diagram shows that some of the signals are absorbed or reflected by the contamination particles as the optical signal attempts to pass from one fiber to the other fiber. [Opt09]
Contamination Diagram courtesy of Optical Dictionary dot com, http://www.opticaldictionary.com/Optical_Dictionary_Connector_Loss_Definition.html
Content is typically used to refer to audio, video and graphic materials used by an application. Sometimes data and applications are also grouped into this term.
Content Protection/Copy Protection (CP)
Content protection is a mechanism to protect the unauthorized copying of video and audio programming.
The range of light and dark values in a picture, or the ratio between the maximum and minimum brightness values. A high-contrast picture would contain intense blacks and whites; a lower-contrast picture would contain only shades of gray.
Contiguous United States. In short, all the states in the U.S. except Hawaii and Alaska. [Sat07]
Device that is attached between the television set and the cable system that can increase the number of channels available on the TV, enabling it to accommodate the multiplicity of channels offered by cable TV.
A unit or device that changes the frequency of carriers to a carrier (or carriers) that can be tuned, detected, and displayed by conventional television receivers at the subscriber’s premises.[Arr11]
A special text file that a Web site stores on your hard drive used to identify you to the Web site the next time you visit. A cookie records your preferences when using a particular site, and can also save the information filled out in online forms. They are used to send browser-specific pages, or pages based on information you have provided to the Web site.
Cooled DFB Laser
Distributed Feedback laser; employs thermoelectric cooler (TEC) to improve laser performance and reliability. Because of its stable wavelength and narrow optical bandwidth, cooled DFB Lasers are commonly used in narrow wavelength DWDM optical communication systems. [Alt09]
Coordinated Universal Time (UTC)
A reference time standard established by the CCIR (a predecessor of the ITU) and maintained by the Bureau International des Poids et Mesures (BIPM). Formerly Greenwich Mean Time (GMT).
Copy Control Information (CCI)
This information is stored on a CableCARD device and delivered to the host to control the copying of content. It is delivered to the CableCARD from the headend, based on arrangements made between the network operator and the content provider.
Common Object Request Broker Architecture
The light-conducting central portion of an optical fiber composed of material with a higher index of refraction than the cladding. The portion of the fiber that transmits light. [Fib111]
Fiber Optic Cable Cross-Section courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c