Wired Broadband and Related Industry Glossary of Terms with Acronyms As of 13 June 2011 Compiled By: Conrad L. Young, Director, Broadband Technical Strategy



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Citizens Band radio.[Arr11]
C-Band

The band of microwave uplink frequencies from 4 to 6 GHZ, and the band of microwave downlink frequencies between 3.7 and 4.2 GHz.[Arr11]
C-Band Satellite
3.7-4.2 gigahertz (Ghz) frequency band used for distribution of programming by most satellite and cable networks.

C-Band Feedhorn



Equipment located at the center of a satellite antenna used to collect C-band (3.7 to 4.2 GHz) signals and direct them into either a low noise amplifier (LNA) or low noise block converter (LNB).[Arr11]

Carrier



The basic radio, television, or telephony center of frequency transmit signal. The carrier in an analog signal. is modulated by manipulating its amplitude (making it louder or softer) or its frequency (shifting it up or down) in relation to the incoming signal. Satellite carriers operating in the analog mode are usually frequency modulated. [Sat07]
Carrier Frequency

The main frequency on which a voice, data, or video signal is sent. Microwave and satellite communications transmitters operate in the band from 1 to 14 GHz (a GHz is one billion cycles per second). [Sat07]
Carrier to Noise Ratio (C/N)

The ratio of the received carrier power and the noise power in a given bandwidth, expressed in dB. This figure is directly related to G/T and S/N; and in a video signal the higher the C/N, the better the received picture. Also referred to as CNR. [Sat07]
Cassegrain Antenna

The antenna principle that utilizes a subreflector at the focal point which reflects energy to or from a feed located at the apex of the main reflector. [Sat07]



CBC
Cipher Block Chaining

CBR
Constant Bit Rate

CCCM
CPE Controlled Cable Modem

CCD

Charge coupled device. In this device charge is stored on a capacitor which are etched onto a chip. A number of samples can be simultaneously stored. Used in MAC transmissions for temporarily storing video signals. [Cha07]



CCI
Copy Control Information

CCITT (now TSS)

Comite Consultatif Internationale de Telegraphique et Telephonique. International body, associated with the ITU, which establishes worldwide standards for telecommunications. Reorganized to include CCIR (radio standards group) and renamed TSS (Telecommunications Standardization Sector). [Sat07]
CCIR

Consultative Committee on Radio; replaced by ITU-R: http://www.itu.int/publications/itur.html [Fib111]
CCIR 601

An international standard (renamed ITU 601) for component digital television that was derived from the SMPTE RP1 25 and EBU 3246E standards. ITU 601 defines the sampling systems, matrix values and filter characteristics for Y, Cr, Cb and RGB component digital television. It establishes a 4:2:2 sampling scheme at 13.5 MHz for the luminance channel and 6.75 MHz for the chrominance channels with eight-bit digitizing for each channel. These sample frequencies were chosen because they work for both 525-line 60 Hz and 625-line 50 Hz component video systems. The term 4:2:2 refers to the ration of the number of luminance channel samples to the number of chrominance channel samples; for every four luminance samples, the chrominance channels are each sampled twice. The D1 digital videotape format conforms to ITU 601. [SVA11]
CCIR 656

The international standard (renamed ITU 601) defining the electrical and mechanical interfaces for digital television equipment operating according to the ITU 601 standard. ITU 656 defines both the parallel and serial connector pinouts, as well as the blanking, sync and multiplexing schemes used in both parallel and serial interfaces. [SVA11]
CCK

Complimentary Code Keying; a direct sequence spread spectrum (DSSS) coding method used in the 802.11b wireless LAN standard for 5.5 and 11 Mbps. The slower 1 and 2 Mbps specifications use Barker coding which has a chip rate of 11 as compared to 8 in CCK. CCK also provides up to 64 coding patterns, whereas Barker uses only one. Unlike CDMA, which overlaps transmissions using different codes, CCK uses the different codes to transmit more data serially (Time Division Multiplexing, TDM). [PCm11]
CCTV

Closed Circuit Television



CD

Compact Disk; often used to describe high-quality audio, CD-quality audio, or short-wavelength lasers; CD Laser. [Fib111]

CDM

Coherence Division Multiplexing
CDMA
Code Division Multiple Access

CDR
Call Detail Record

CDS

Correlated Double Sampling; a technique used in the design of some CCD cameras that reduces the video signal noise generated by the chip. [SVA11]
CE
Consumer Electronics

CEA
Consumer Electronics Association

Cell
ATM layer protocol data unit.


Cell

In cellular mobile telephony, the geographic area served by one transmitter or base station transmit element. Subscribers may move from cell to cell.[Arr11]
Cellular
A wireless telephone system where each geographic area (cell) is covered by a base station; users are handed over to other base stations as they move from cell to cell; analog and digital systems exist.

Celsius



Measure of temperature where pure water freezes at 0° and boils at 100°. [Fib111]
Center Conductor

The centermost feature of coaxial cable, it consists of solid copper or copper clad aluminum wire. Signals travel along the outside of the center conductor.[Arr11]
Center Mount

A type of mounting bracket, located at the center of an off-air antenna, designed to fasten the antenna to a structure.[Arr11]

Center Wavelength



In a laser, the nominal value central operating wavelength. It is the wavelength defined by a peak mode measurement where the effective optical power resides (see illustration). In an LED, the average of the two wavelengths measured at the half amplitude points of the power spectrum. [Fib111]

Center Wavelength Illustration courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c


Center Wavelength and Bandpass
Coupler performance is usually specified over a wavelength window, or in some cases, multiple windows. The center wavelength is the nominal wavelength of operation of the coupler, while the bandpass is the range of wavelengths over which the specifications are guaranteed. In many cases, couplers will perform adequately over a range outside their bandpass, but adherence to specifications is not guaranteed in this region. [AOF11]

Central Office (CO)


A switching system that connects lines to lines and lines to trunks. The term is sometimes used loosely to refer to a telephone company building in which a switching system is located and to include other equipment (such as transmission system terminals) that may be located in such a building.

Certificate


A message that, at least, states a name or identifies the Certification Authority (CA), identifies the Subscriber, contains the Subscriber's public key, identifies the Certificate's Validity Period, contains a Certificate serial number, and is digitally signed by the CA that issued the certificate.

Certificate of Compliance


The approval of the FCC that must be obtained before a cable system can carry television broadcast signals.


Certificate Revocation List (CRL)
A list of revoked certificates published by each certificate authority.


Certification Authority (CA)
An entity authorized to issue, manage, revoke, and renew Certificates.

CFA



Color Filter Array; a set of optical pixel filters used in single-chip color CCD cameras to produce the color components of a video signal. [SVA11]
CGA

Color Graphics Adapter; a low-resolution color standard for computer monitors. [Fib111]
Channel
A transmission path between two points. The term channel may refer to a one-way path or, when paths in the two directions of transmission are always associated, to a two-way path. It is usually the smallest subdivision of a transmission system by means of which a single type of communication service is provided, i.e. a voice channel, teletypewriter channel, or data channel.

Channel Capacity
The number of channels available for current or future use on a cable system.

Chassis Mounting Connector



Another name for pin-type connector.[Arr11]
CHILA
CableCARD-Host Interface License Agreement

Chirp



In laser diodes, the shift of the laser’s center wavelength during single pulse durations. [Fib111]. Chirp is the frequency (or phase) modulation, wanted or unwanted, resulting from a signal intensity modulation. A chirped signal will exhibit a modification of its spectrum as long as it travels along a fiber. Depending upon the sign of the chirp and of the dispersion of the fiber, a short pulse can be enlarged or compressed during propagation. To characterize the chirp of a signal, a chirp parameter α is defined as the ratio between phase modulation and intensity modulation. One method to measure the chirp parameter is the frequency discrimination technique, whereby the induced phase modulation is converted in phase modulation via a Gaussian tunable optical filter placed just after the modulator. The temporal signal is recorded on both sides of the optical filter. The temporal chirp parameter is related to the ratio of the difference and the sum of both measurements. [Jer04]

Laser Chirp Graph courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c


Chroma

1. Attribute of a visual sensation that permits a judgment to be made of the amount of pure chromatic color present. 2. The portion of a composite video signal that carries the chrominance values, including hue and saturation. [Pho11]
Chroma Crawl

An artifact of encoded video, also known as dot crawl or cross-luminance, occurs in the video picture around the edges of highly saturated colors as a continuous series of crawling dots and is a result of color information being confused as luminance information by the decoder circuits. [SVA11]
Chroma Keying

In television, nearly instantaneous switching between multiple video signals, based on the state, i.e., phase, of the color (chroma) signal of one, to form a single composite video signal. Note 1: Chroma keying is used to create an overlay effect in the final picture, e.g., to insert a false background, such as a weather map or scenic view, behind the principal subject being photographed. Note 2: The principal subject is photographed against a background having a single color or a relatively narrow range of colors, usually in the blue or green. When the phase of the chroma signal corresponds to the preprogrammed state or states associated with the background color, or range of colors, behind the principal subject, the signal from the alternate, i.e., false, background is inserted in the composite signal and presented at the output. When the phase of the chroma signal deviates from that associated with the background color(s) behind the principal subject, video associated with the principal subject is presented at the output. Synonyms color keying, [loosely] blue-screening, [in security] keying. [ATI11]
Chromatic Dispersion

Reduced fiber bandwidth caused by different wavelengths of light traveling at different speeds down the optical fiber. Chromatic dispersion occurs because the speed at which an optical pulse travels depends on its wavelength, a property inherent to all optical fiber. May be caused by material dispersion, waveguide dispersion, and profile dispersion. [Fib111]

Dispersion Graph courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c


Chrominance Signal
That portion of the NTSC color television signal that contains the color information. The chrominance signal is created by adding a 3.579545 MHz sine wave to a monochrome television signal. The signal is ignored by monochrome television receivers, but is picked up and decoded by a color set as part of the broadcast. The colors are shifted by degrees, and usually come in pairs to graph the full color spectrum. [Glo07]

Chrominance-to-Luminance Crosstalk

Also referred to as Chrominance-to-Luminance Intermodulation and Cross-Modulation (XMOD). An undesirable change in luminance amplitude caused by superimposition of some chrominance information on the luminance signal. Appears in a TV picture as unwarranted brightness variations caused by changes in color saturation levels. [SVA11]
CIE

Commission International de l'Eclairage (International Commission on Illumination). An international standards-setting organization, based in Vienna, Austria, which is concerned with the development of (a) color-matching systems, (b) recommended practices and standards concerning the properties and applications of light, and (c) methods of measurement pertaining thereto. [ATI11]
CIF

Common Intermediate Format. A compromise television display format adopted by the CCITT which is relatively easy to derive from both PAL and NTSC. [Sat07]
CIN

Composite Intermodulation Noise. CIN ≡ The ratio of the CW carrier to the noise-like signals generated by the non-linearity of a broadband transmission system carrying a combination of analog signals and digitally modulated signals. These distortion products are analogous to the CSO and CTB products generated by analog carriers, but due to the pseudo random nature of the digital modulation signals, appear as a noise-like interference. When CIN products fall within the analog portion of the spectrum, their effect on the analog signal is similar to increasing thermal (random) noise. Since CIN is a distortion product, its contribution is dependent on the output signal level. Source: ANSI/SCTE 17 2007 Test Procedure for Carrier to Noise (C/N, CCN, CIN, and CTN)”, dated 05 October 2007.
Cipher
An algorithm that transforms data between plaintext and ciphertext.

Ciphersuite
A set which must contain both an encryption algorithm and a message authentication algorithm (e.g., a MAC or an HMAC). In general, it may also contain a key-management algorithm, which does not apply in the context of PacketCable.

Ciphertext


The (encrypted) message output from a cryptographic algorithm that is in a format that is unintelligible.

Circuit


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