Conrad L. Young’s Wired Broadband and Related Industry Glossary of Terms with Acronyms As of 15 February 2012 Open Access This document is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial
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Coring/Stripping Tool A tool which strips aluminum sheathed coaxial cable and cores the dielectric foam, leaving the cable prepared to accept a connector. (Arris Glossary of Terms) CoS Class of Service Counter-Rotating An arrangement whereby two signal paths, one in each direction, exist in a ring topology. (FiberOpticsInfo) 
Counter-Rotating Signal Path Illustration courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c Couplers In fiber optics, a device which links three or more fibers, providing two or more paths for the transmission signal. In an "active" coupler, a switching mechanism selects among several routes; in a "passive" coupler, routing is determined by the geometry of the device. (Arris Glossary of Terms) An optical device that combines or splits power from optical fibers. (FiberOpticsInfo) 
Fused Coupler Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c
Continuous Power Bus. Provides downstream power and RF signal with tap faceplate removed. (Arris Glossary of Terms) CPD Common Path Distortion CPE Customer Premises Equipment CPE Controlled Cable Modem A cable modem in which a portion of the higher-layer processing is performed by an external device, in particular, by a PC. CPPI 100 Gbps Parallel Physical Interface; the “C” usually denotes 100 Gbps nominal data rate. (Traverso) CRA Certificate Requesting Authority Crash Point A term used to describe the RF output produced by an amplifier or other active component that correlates to a level where the predicted linear performance models for multi-carrier distortion parameters composite second order (CSO), composite triple beat (CTB), and cross modulation (XMOD) described below are no longer valid. At or beyond the crash point any additional increase in RF power output level results in increased levels of non-linearity, as measured by CSO, CTB, and XMOD, that are worse than predicted by the mathematical relationships described below. A one (1) dB change of the output of an amplifier changes CSO by 1 dB. A one (1) dB change of the output of an amplifier changes the CTB ratio by 2 dB. A one (1) dB change of the output of an amplifier changes the cross modulation (XMOD) by 2 dB. (Blonder Tongue Laboratories) The above assumes a channel loading consisting of more than one-third (1/3) analog carriers with the remaining transmitted spectrum consisting of digital content. In environments where the channel loading is approximately greater than two-thirds (2/3) transmitted content the crash point of an active component, module, or device may be determined and described using a set of measured criteria as described below:
Under predominantly digital channel loading an active device’s crash point may be identified when one or more of the measured criteria above have exceeded pre-set limits. CRC Cyclic Redundancy Check; an error-detection scheme that (a) uses parity bits generated by polynomial encoding of digital signals, (b) appends those parity bits to the digital signal, and (c) uses decoding algorithms that detect errors in the received digital signal. Note: Error correction, if required, may be accomplished through the use of an automatic repeat-request (ARQ) system. Also, an error checking mechanism that checks data integrity by computing a polynomial algorithm based checksum. [INFOSEC-99] (ATIS) Crest Factor Also referred to as peak-to-average ratio (PAR) or peak-to-average power ratio (PAPR); a measurement of a waveform, calculated from the peak amplitude of the waveform divided by the RMS value of the waveform. 
It is therefore a dimensionless quantity. While this quotient is most simply expressed by a positive rational number, in commercial products it is also commonly stated as the ratio of two whole numbers, e.g., 2:1. In signal processing applications it is often expressed in decibels (dB). The minimum possible crest factor is 1, 1:1 or 0 dB. (Wikipedia) This table provides crest factor values for some normalized waveforms: 
Notes: 1. crest factors specified for QPSK, QAM, and WCDMA are typical factors needed for reliable communication, not the theoretical crest factors which can be larger. Crimp Ring A metallic ring which will be mechanically shaped to pro-vide retention of the coaxial cable braid and jacket onto "F" type connectors. They are usually incorporated into these connectors. (Arris Glossary of Terms) Crimp Tool A tool used to provide retention of an "F" type connector onto the braid and jacket of a drop cable. (Arris Glossary of Terms) Critical Angle In geometric optics, at a refractive boundary, the smallest angle of incidence at which total internal reflection occurs. (FiberOpticsInfo) 
Critical Angle Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/c Critical Length Distance along a specific cable to cause worst-case mismatch reflection. A function of frequency-attenuation-velocity of propagation parameters of specific cable types. CRL Certificate Revocation List Cross Connect The physical connection between patch panels or punch-down blocks that facilitates connections from systems and feeds to drops. (Linear LLC) Connections between terminal blocks on the two sides of a distribution frame or between terminals on a terminal block (also called straps). Also called cross-connection or jumper. (FiberOpticsInfo)
A form of television signal distortion where modulation from one or more television channels is imposed on another channel or channels. Also referred to as XMOD. Cross-gain Modulation (XGM) A technique used in wavelength converters where gain saturation effects in an active optical device, such as a semiconductor optical amplifier (SOA), allow the conversion of the optical wavelength. Better at shorter wavelengths (e.g. 780 nm or 850 nm). (FiberOpticsInfo) Cross-phase Modulation (XPM) A fiber nonlinearity caused by the nonlinear index of refraction of glass. The index of refraction varies with optical power level which causes different optical signals to interact. (FiberOpticsInfo) Cross Ownership Ownership of two or more kinds of communications outlets by the same individual or business. The FCC prohibits television stations and telephone companies from owning cable systems in their service areas. Television networks are prohibited from owning cable systems anywhere in the U.S. Crosstalk Noise passed between communications cables or device elements. 1) Undesired coupling from one circuit, part of a circuit, or channel to another. 2) Any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates and undesired effect in another circuit or channel. (FiberOpticsInfo) CRT Cathode Ray Tube Cryptanalysis The process of recovering the plaintext of a message or the encryption key without access to the key. Cryptographic Algorithm An algorithm used to transfer text between plaintext and ciphertext.
Common Scrambling Algorithm CSCF Call State Control Function CSD Circuit Switched Data CSMA/CD Carrier Sense Multiple Access with Collision Detection; a network control protocol in which (a) a carrier sensing is used and (b) while a transmitting data station that detects another signal while transmitting a frame, stops transmitting that frame, waits for a jam signal, and then waits for a random time interval before trying to send that frame again. (FiberOpticsInfo) CSO Composite Second Order Beat CSR Customer Service Representative CSS Cascading Style Sheets CSU Channel Service Unit; A digital interface device that connects end-user equipment to the local digital telephone loop. CSU is frequently coupled with DSU (see below) as CSU/DSU. (Satnews)
Circuit Switched Voice CTB Composite Triple Beat CTIA Cellular Telecommunications Industry Association CTP Compliance Test Plan CTS Clear To Send; in a communications network, a signal from a remote receiver to a transmitter that it is ready to receive a transmission. (FiberOpticsInfo) Cumulative Leak Index (CLI) A standard measurement of system leakage; when cable network equipment, coaxial cable, and connectors are imperfectly shielded signals leak out of the system (referred to as “egress”). Signal egress interferes with radio communications services and is of particular concern when it affects aeronautical navigation and communication services. The US Federal Communication Commission (FCC) therefore has stringent regulations regarding cable system egress in the 108 to 137 MHz and 225 to 400 MHz frequency bands. (Rhea, Cable Television Signal Distribution) Current, Alternating (AC) An electric current that periodically reverses the direction of electron flow. The rate at which a full cycle occurs in a given unit of time (generally a second) is called the frequency of the current. (Arris Glossary of Terms) Current, Direct (DC) Electrical current whose electrons flow in one direction only. It may be constant or pulsating as long as the movement is in the same direction. (Arris Glossary of Terms) Custom Local Area Signaling Services (CLASS) This term refers to a set of voice telephony services that make use of information about the calling or called numbers. Examples are caller ID, Automatic recall (*69), anonymous call rejection, etc. Customer Premises Equipment (CPE) Equipment at the end user's premises; MAY be provided by the end user or the service provider. Customer Service Representative (CSR) Customer service representative. Cutback Method A technique of measuring optical fiber attenuation by measuring the optical power at two points at different distances from the test source. (FiberOpticsInfo) Cutoff Frequency That frequency beyond which no appreciable energy is transmitted. It may refer to either an upper or lower limit of a frequency band. Cutoff Frequency A photo detector (PD) specification describing the frequency at which the PD photocurrent decreases by 3-dB from its highest level low frequency response. (Zanger)
In single-mode fiber (SMF), the wavelength below which the fiber ceases to be single-mode. (FiberOpticsInfo) CVC Code Verification Certificate CW Control Word CW Continuous Wave; usually refers to the constant optical output from an optical source when it is biased (i.e., turned on) but not modulated with a signal. (FiberOpticsInfo) CWDM Coarse Wavelength Division Multiplexing Cycle One complete sequence of values of an alternating wave starting at zero, increasing to a maximum positive value, decreasing to zero, increasing to a maximum negative value, and decreasing to zero again. Also called a Hertz (Hz). (Arris Glossary of Terms) Cyclic Redundancy Check (CRC) An algorithm to detect data corruption. D: D1 A format for component digital video tape recording working to the ITU-R 601, 4:2:2 standard using 8-bit sampling. (FiberOpticsInfo) D2 The VTR standard for digital composite (coded) NTSC or PAL signals that uses data conforming to SMPTE 244M. (FiberOpticsInfo) D3 A composite digital video recording format that uses data conforming to SMPTE 244M. (FiberOpticsInfo) D5 An uncompressed tape format for component digital video which has provisions for HDTV recording by use of 4:1 compression. (FiberOpticsInfo) D Channel An ISDN Data channel is a data connection between the telephone company's switching equipment and a customer's ISDN equipment. It carries telephone connection information—signals to tell your equipment that a call is coming in and carry dialing and call handling information to the phone company's equipment— and can also be used to carry multiple low-speed data connections using the X.25 packet-switching protocol. DAC Digital-to-Analog Converter; a device used to convert digital signals to analog signals. (FiberOpticsInfo) 
Digital-to-Analog Converter (DAC) Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/d DAMA Demand-Assigned Multiple Access; A highly efficient means of instantaneously assigning telephony channels in a transponder according to immediate traffic demands. (Satnews) DANL Displayed Average Noise Level or “Noise Floor” is the specified noise level of a spectrum analyzer when terminated with a 50-Ohm load. (Yurick) DANL is dependent on various settings of the instrument, and is typically specified along with the conditions at which it was measured. For example, a typical DANL specification might read something like: -115 dBm between 1 GHz and 2.7 GHz with resolution bandwidth (RBW) set to 1 kHz with 0 dB input attenuation at 25deg C. Because the apparent noise floor of the instrument increases with a wider resolution bandwidth, the noise floor is often normalized to a common RBW, which is often 1 Hz. (NationalInstruments) Dark Current The current through the photodiode in the absence of light, when it is operated in photoconductive mode. The dark current includes photocurrent generated by background radiation and the saturation current of the semiconductor junction. Dark current must be accounted for by calibration if a photodiode is used to make an accurate optical power measurement, and it is also a source of noise when a photodiode is used in an optical communication system. (Zanger) Dark Fiber Fiber-optic cable that has been deployed but does not have the proper electronic and optical equipment to carry optical (light) signals. Generally considered to be extra fiber that will support future demand for communications capacity. DASE Digital Application Software Environment Data Communication The movement of encoded information by means of electrical transmission systems. The transmission of data from one point to another over communication channels. Data Compression A technique that saves storage space by eliminating gaps, empty fields, redundancies, or unnecessary data to shorten the length of records or blocks. Data Dependent Jitter (DDJ) Also called data dependent distortion. Jitter related to the transmitted symbol sequence. DDJ is caused by the limited bandwidth characteristics, non-ideal individual pulse responses, and imperfections in the optical channel components. (FiberOpticsInfo) Data Link A fiber optic transmitter, cable and receiver that transmits digital data between two points. (Arris Glossary of Terms) Data Link Layer Layer 2 in the Open System Interconnection (OSI) architecture; the layer that provides services to transfer data over the transmission link between open systems. Data Rate The number of bits of information in a transmission system, expressed in bits per second (b/s or bps), and which may or may not be equal to the signal or baud rate. (FiberOpticsInfo) Data Over Cable Service Interface Specifications (DOCSIS®) Specification for transmission of data over a cable network that has been approved by the ITU as an international standard. DOCSIS® was developed by CableLabs and a consortium of North American multi-system cable operators. DAVIC Digital Audio Visual Council dB Decibel DBA Dynamic Bandwidth Allocation dBc A measure of spurious signal level. The level is measured relative to the nominal unmodulated carrier level. (Arris Glossary of Terms) dBi Decibel-isotropic; a unit of measure that expresses a ratio of power, measured in decibels, referring to the gain or loss relative to a dipole antenna. (Arris Glossary of Terms) dBµV dB micro volts. A measurement of ‘x dBµV’ indicates that the signal is x dB above one microvolt in 75 ohms. To convert x microvolts to dBµV: dBµV = 20 log (x microvolts). (Blonder Tongue Laboratories) dBm Decibel referred to one milliwatt; 0 dBm = 1 mW. (Arris Glossary of Terms) dBmV dB milli volts. A measure of signal amplitude. 0 dBmV is equivalent to 1 mV RMS across the given impedance (usually 75 Ohms). (Arris Glossary of Terms). dBmV and dBµV are expressions of power that contain an upper case “V”. This does not mean they are expressions of voltage. They are expressions of power. When all the power scales (dBm, dBmV and dBµV) are laid next to each other, it is easy to see that each track on a dB for dB basis. A power measurement of ‘x dBmV’ indicates that a particular signal is x dB greater than (‘above’) 1 millivolt in 75 ohms. A negative dBmV value indicates that the signal is x dB less than (‘below’) 1 millivolt in 75 ohms. To convert x millivolts to dBmV: dBmV = 20 log (x millivolts) (Blonder Tongue Laboratories) dBRL Return loss as measured with a TDR and expressed in dB. It is the ratio of power levels between an outgoing pulse and its reflection. This unit of measure can assist in determining the severity of a cable fault. (Arris Glossary of Terms) DBS Direct Broadcast Satellite; also referred to as SATCOM-DBS. An alternative to cable and analog satellite reception that uses a fixed 18-inch dish focused on one or more geostationary satellites. DBS units receive multiple channels of multiplexed video and audio signals as well as programming information and related data. Also known as digital satellite system. (FiberOpticsInfo) dBW The ratio of the power to one Watt expressed in decibels. (Satnews) DC Direct current. See also current, direct. DCD Duty Cycle Distortion Jitter (FiberOpticsInfo) DC Power Block A device which stops the flow of dc power but permits passage of higher frequency ac signals. (Channel Vision)
Digital Certificate Authorization Agreement DCE Data Circuit-terminating Equipment. 1) In a data station, the equipment that performs functions such as signal conversion and coding, at the network end of the line between the data terminal equipment (DTE) and the line, and may be a separate or an integral part of the DTE or of intermediate equipment. 2) The interfacing equipment that may be required to couple the data terminal equipment (DTE) into a transmission circuit or channel and from a transmission circuit of a channel into the DTE. (FiberOpticsInfo) DCR Digital Cable Ready DCT Discrete Cosine Transform (FiberOpticsInfo) DDE-1 Declarative Data Essence DDJ Data Dependent Jitter (FiberOpticsInfo) Dead Zone Period of time after a reflected pulse is detected before another feature may be measured. (Arris Glossary of Terms) De-BPSK Differential Binary Phase Shift Keying (Satnews) Decibel (dB) A unit to measure the relative levels of current, voltage or power. An increase of 3 dB indicates a doubling of power, an increase of 10 dB indicates a 10x increase in power, and an increase of 20 dB indicates a 100x increase in power. Download 2.22 Mb. Share with your friends:
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