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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A device able to recreate an image placed in front of it based on the charge it collected. Invented by Philo Farnsworth, it was an important step in the development of signal transfer for early television devices, but was a poor conductor and needed very high light levels to work properly. (Glossary of Terms dot Net) Impedance The total opposition a circuit, cable or component offers to alternating current. It includes both resistance and reactance and is generally expressed in Ohms. (Arris Glossary of Terms) Impedance Match A condition whereby the impedance of a particular circuit, cable or component is the same as the impedance of the circuit, cable or component to which it is connected. (Arris Glossary of Terms) Impedance Mismatch The characteristic impedance of coaxial cable, amplifiers, passive devices and components within most of a cable network is 75 Ohm (Ω). When a propagating signal encounters a discontinuity resulting in other than the desired characteristic impedance, some of its energy is reflected at the discontinuity and propagates in the opposite direction. The unit of mismatch is known as “return loss” (RL) and is measured in decibels (dB). For example, a 10-dB RL signifies that the mismatch results in a reflected signal that is 10 dB below the incident power to the mismatch. The reflected signal causes two (2) primary undesirable effects: (1) signal amplitude variation with frequency, and (2) ghosting. Amplitudes vary because the reflected signal vectorially adds with the desired forward signal. Because the path phase length is a function of frequency, the resulting signal level is also a function of frequency (nonflat response or nonflatness). A severe mismatch (e.g., resulting from a connector failure) can cause signal suck-outs that prevent required channel-to-channel flatness. A number of marginal mismatches cascaded throughout the system can result in smaller magnitude variations that are complex in shape and difficult to correct. A second difficulty with mismatches is the introduction of a secondary picture image displaced horizontally from the desired picture image on the television display (aka as a “ghost”). Ghosting results when a multiplied reflected signal arrives at the television receiver in addition to, but later than, the desired original signal. When time displacement is small due to a short reelection path, the ghost level must be strong to be objectionable. When time displacement is large enough to clearly separate the reflected image from the desired image lower level ghosts are objectionable. Pierre Mertz first researched this effect in 1953. (Mertz) A graphic representation of his results is known as the “Mertz Curve”. Ghosting is not objectionable when all cable system components have a RL better than 16 dB. (Hartwick) Impression Billing standard for video ads running in all types of content. (Fain) Impulse Noise Short bursts of high-level noise such as that resulting from the coupling of transients into a channel. Typical sources of such noises are lightning and transients from switching systems. Impulse noise, which sounds like a click, is not particularly detrimental to voice communications, but it can be detrimental to data communications. Also known as noise characterized by non-overlapping transient disturbances. Impulse-Pay-Per-View (IPPV) A service that allows a user to order and receive pay-per-view content in near real-time. Current pay-per-view models require that the user make arrangements to purchase the content prior to its reception. Inclination The angle between the orbital plane of a satellite and the equatorial plane of the earth. (Satnews) Incremental Related Carriers (IRC) A method of spacing National Television Systems Committee (NTSC) television channels on a cable television system in which all channels except 5 and 6 correspond to the standard channel plan, used to reduce composite triple beat distortions. Incumbent Local Exchange Carrier (ILEC) This term refers to traditional local telephone companies such as one of the Regional Bell Operating Companies (RBOCs) in the United States. Independent A TV station that has no exclusive affiliation which obliges it to carry programs from one of the national networks. Individually-owned and operated cable television system, not affiliated with a Multiple System Operator. Independent Operator Individually owned and operated cable television system, not affiliated with an MSO. Index of Refraction The ratio of the velocity of light in free space to the velocity of light in a fiber material. Always greater than or equal to one. Also called refractive index. n = C/V Where: C = The speed of light in a vacuum. V = The speed of the same wavelength in the fiber material. (FiberOpticsInfo) Index Matching Fluid A fluid whose index of refraction nearly equals that of the fibers core. Used to reduce Fresnel reflection loss at fiber ends. Also known as index-matching gel. (FiberOpticsInfo) Index Matching Material A material, often a liquid or cement, whose refractive index is nearly equal to an optical element index. Material with an index nearly equal to that of an optical fiber’s core is used in splicing and coupling to reduce reflections from the fiber end face. (Arris Glossary of Terms) Index Profile A characteristic of an optical fiber which describes the way its index of refraction changes with its radius. (Arris Glossary of Terms) Inductance The ability of a device to store energy in the form of a magnetic field. Inductor An electronic component designed to provide a controlled amount of inductance. Industry Standard Architecture (ISA) An interface standard for connecting hardware expansion cards to a computer. The typical ISA connection is a slot, or edge-card connector, on the computer's motherboard allowing devices such as sound cards and telephone modems to be plugged in to the computer. Infomercial A commercial, usually 90 seconds or more in length, designed to supply information about a product or service rather than to present a specific sales message. Infrared Electromagnetic radiation with wavelength between 0.7 micrometer and about 1 millimeter. Wavelengths at the shorter end of this range are frequently called "near" infrared, and those longer than about 20 micrometers, "far" infrared. (Arris Glossary of Terms) Infrared Emitting Diode LEDs that emit infrared energy (830 nm or longer). (FiberOpticsInfo) Infrared Fiber Optical fibers with best transmission at wavelengths of 2 mm or longer, made of materials other than silica glass. See also fluoride glasses. (FiberOpticsInfo) InGaAs Indium Gallium Arsenide; generally used to make high-performance long-wavelength detectors. (FiberOpticsInfo) InGaAsP Indium Gallium Arsenide Phosphide; generally used for long-wavelength light emitters. (FiberOpticsInfo) Ingress A condition where unwanted RF signal leaks into a distribution system. (Linear LLC) In-Line Amplifier An erbium doped fiber amplifier (EDFA) or other type of amplifier placed in a transmission line to strengthen the attenuated signal for transmission onto the next, distant site. In-line amplifiers are all-optical devices. (FiberOpticsInfo) 
In-Line Amplifier Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/i In-Line Equalizer A network device designed to compensate for the frequency/ loss characteristics of a coaxial cable, so as to permit the system to pass all frequencies in a uniform manner. 
Excerpt from ANSI/SCTE 87-1 2008, “Graphic Symbols For Cable Systems Part 1: HFC Symbols”
Institute of Radio Engineers (IRE) A professional organization which existed from 1912 until January 1 1963, when it merged with the American Institute of Electrical Engineers (AIEE) to form the Institute of Electrical and Electronics Engineers (IEEE).[1] (Wikipedia)
Institute for Telecommunications Sciences (ITS) ITS is the research and engineering branch of the National Telecommunications and Information Administration (NTIA), a part of the U.S. Department of Commerce (DOC). For more information, refer to http://www.its.bldrdoc.gov/ Institution of Electrical Engineers (IEE) Institutional Network A network that is operated in conjunction with a cable TV system and which is designed to satisfy the needs of schools, businesses, or government. Insulation A material having dielectric properties which is used to separate close electric components such as cable conductors and circuit components. (Arris Glossary of Terms) Insulator The insulator keeps the pin section of the terminal centered in the entry barrel of a connector. (Arris Glossary of Terms) Integral Mandrel (Integral Sleeve) The function of this sleeve is to support the aluminum sheath of the cable. As the ferrule closes down to grip the sheath, the sleeve maintains the size and shape of the aluminum sheath. If the sheath were to crush down unsupported, mechanical and electrical problems could occur. (Arris Glossary of Terms) Integrated Circuit A circuit whose connections and components are fabricated into one integrated structure on a certain material such as silicon, gallium arsenide (GaAs), indium phosphide (InP), or gallium nitride (GaN). Integrated Detector/Preamplifier (IDP) A detector package containing a PIN photodiode and transimpedance amplifier. (FiberOpticsInfo) Integrated Services Digital Network (ISDN) ISDN is a digital telephone line that can be used for voice, fax, and data communications like a regular telephone line, but can transport data five times faster (or more) than a 28.8Kbps V.34 modem and allow you to talk on the phone to one person while sending data to another. Integrated Services Digital Network User Part (ISUP) ISUP is a protocol within the Signaling System Number 7 (SS7) suite of protocols that is used for call signaling within an SS7 network. Integrity A way to ensure that information is not modified except by those who are authorized to do so. INTELSAT The International Telecommunications Satellite Organization operates a network of satellites for international transmissions. (Satnews) Intensity The square of the electric field strength of an electromagnetic wave. Intensity is proportional to irradiance and may get used in place of the term “irradiance” when only relative values are important. (FiberOpticsInfo) Intensity Information Intensity information is part of a television broad cast signal. The intensity information sent to televisions tells the electron beam how bright or dim a group of phosphors need to be for the image to be viewed properly. This is essential for proper reconstruction, and also helps with color construction as it tells the electron beams the proper intensity for each color. Without intensity information, all the blues on a screen would be the same color and intensity, as would all the reds, etc. (Glossary of Terms dot Net) Intensity Modulation In optical communications, a form of modulation in which the optical power output of a source varies in accordance with some characteristic of the modulating signal. (FiberOpticsInfo) Interactive Cable Cable systems that have the technical ability to let subscribers communicate directly from their television sets with a computer at the system headend using special converters and regular cable lines. Viewers are able to order movies and video games, access library information, and request sales brochures and coupons from home. Interactive Program Guide (IPG) A guide similar to an EPG, but with increased interactive features, such as allowing users to sort through onscreen TV listings by time, or channel, or themes, like children's shows, and program a VCR or TV directly from within the guide. Interactive Television (ITV) A combination of television with interactive content and enhancements. ITV provides a richer entertainment experience as well as information, blending traditional TV viewing with the interactivity of a PC. ITV features can include richer graphics, Internet access, e-mail, chat, instant messaging, home shopping, home banking, interactive games, on-demand services such as weather and financial information, pay-per-view (PPV), and video-on-demand (VOD). Or a catch all phrase for services/platforms that allow TV viewers to interact with their television. Typical services might include interactive program guides and e-mail and web browsing on the TV. Interactive Voice Response System (IVR) The automated telephony systems we are all familiar with that direct our calls within a company or organization, e.g., “Please press one for customer service, press two for technical support, press zero for the operator.” Interchannel Isolation The ability to prevent undesired optical energy from appearing in one signal path as a result of coupling from another signal path. Also called crosstalk. (FiberOpticsInfo) Interchangeability The ability to exchange tapes between different manufacturers' videotape recorders with no appreciable degradation of playback image. Interconnect Two or more cable systems distributing a programming or commercial signal simultaneously. Interconnect Cabinet Cabinets containing connector panels that interface between outside plant cables and jumper cables leading to optoelectronic equipment. Used as access points for testing and rear-ranging outside plant fibers. (Arris Glossary of Terms) Interdiction A method of receiving TV signals by jamming unauthorized signals but having all other signals received in the clear. Because the jamming is accomplished outside the home it does not require a set-top terminal in the home. Inter-exchange Carrier (IC) A communications common carrier that provides telecommunications services between Local Access and Transport Areas (LATA) or between exchanges within the same LATA. Inter-Exchange Carrier (IEC) A long distance phone carrier, like AT&T, MCI, or Sprint. Also referred to as an IXC. Interface A shared boundary defined by common physical interconnection characteristics, signal characteristics, and meanings of inter-changed signals. (Arris Glossary of Terms) Interference Energy which tends to interfere with the reception of the desired signals, such as fading from airline flights, RF interference from adjacent channels, or “ghosting” from reflecting objects such as mountains and buildings. Interference Rejection Reception of unwanted signals is interference; smart antenna systems reject interference by nulling the unwanted signal through phase shifting; they also reduce interference to other systems by nulling the transmitted signal in the direction of the unintended receiver. Interferometer An instrument that uses the principle of interference of electromagnetic waves for purposes of measurement. Used to measure a variety of physical variables, such as displacement (distance), temperature, pressure, and strain. (FiberOpticsInfo) Interferometric Intensity Noise (IIN) Noise generated in optical fiber caused by the distributed back reflection that all fiber generates mainly due to Rayleigh scattering. OTDRs make use of this scattering power to deduce the fiber loss over distance. (FiberOpticsInfo) Interferometric Sensors Fiber optic sensors that rely on interferometric detection. (FiberOpticsInfo) Interlaced Scanning (Interlace) A scanning process in which each adjacent line belongs to the alternate field. Interlacing The scanning format of standard television screens. In an interlace format, the entire screen is painted with the electron beam, but in alternating lines. On the first pass the odd-numbered lines are painted, and then the beam makes a second pass to paint the even–numbered lines. In the United States, standard televisions have 525 lines of resolution and the screen is refreshed 30 times a second. This means an interlacing beam paints over 15,000 lines a second. (Glossary of Terms dot Net) InterLATA Inter-Local Access and Transport Area; 1. Between local access and transport areas (LATAs). 2. Services, revenues, and functions related to telecommunications that begin in one LATA and that terminate in another or that terminate outside of the LATA. (FiberOpticsInfo) Inter-Local Access and Transport Area (InterLATA) This term refers to services provided across local access and transport areas (LATAs), roughly corresponding to the concept of long-distance communication. The 1984 breakup of AT&T opened up competition for interstate calls, and most states soon allowed competition for calls between LATAs within their states. Regional Bell operating companies (RBOCs) currently are prohibited from providing inter-LATA service until they meet certain requirements related to opening their networks to competitors as detailed in the Telecommunications Act of 1996. Intermediate Frequency (IF) A frequency to which a signal is converted for ease of handling. Receives its name from the fact that it is an intermediate step between the initial and final conversion or detection stages. (Arris Glossary of Terms) Superheterodyne architecture radio receivers typically employ one or more IF stages, whereas Zero-IF radio receivers do not employ IF stages. Intermodulation In a receiver, an unwanted signal sometimes interacts with the desired signal. The desired signal appears to be modulated by the undesired signal. Intermodulation (Mixing) A fiber nonlinearity mechanism caused by the power dependent refractive index of glass. Causes signals to beat together and generate interfering components at different frequencies. Very similar to four wave mixing. (FiberOpticsInfo) Intermodulation Distortion Form of interference involving the generation of interfering beats between two or more carriers according to the frequency relationship f=nf1+/- mf2, where n and m are whole numbers (but not zero), with appropriate expansion for additional carriers. The distortion introduced when several or many carriers are passed through a nonlinear circuit. This includes the spurious signals (beats) produced as sum and difference additions of the carriers present, and the transfer or superimposition of modulating information from one carrier to another. (Arris Glossary of Terms) Intermodulation Noise Spurious frequencies, such as sum and difference frequencies, which are the products of frequencies transmitted through a nonlinear circuit. (Arris Glossary of Terms) International Electrotechnical Commission (IEC) An international standards body. International Organization for Standardization (ISO) An international standards body, commonly known as the International Standards Organization. International Telecommunications Union (ITU) A United Nations organization that establishes standards for telecommunications devices, like ISDN hardware, modems, and Fax machines. ITU standards include J.112, J.122, H.323, V.90, X.25, and X.500. ITU is a civil international organization, headquartered in Geneva, Switzerland, established to promote standardized telecommunications on a worldwide basis. The ITU-R and the ITU-T are committees under the ITU, which is recognized by the United Nations as the specialized agency for telecommunications. (FiberOpticsInfo) http://www.itu.int/ Internet A series of interconnected local, regional, national and international networks linked using the Internet Protocol. The Internet is accessible via telephony wires, HFC networks and by satellite. Internet Assigned Numbered Authority (IANA) The entity responsible for assigning numbers in the Internet Suite of Protocols. Internet Control Message Protocol (ICMP) An internet network layer protocol. Internet Engineering Task Force (IETF) A body responsible for, among other things, developing standards used in the Internet. Or a cooperative consortium that standardizes internet protocols, naming and other communications issues. Internet Group Management Protocol (IGMP) A network-layer protocol for managing multicast groups on the Internet. Internet Key Exchange (IKE) A method standardized by the IETF for exchanging security keys. Internet Protocol (IP) The computer network protocol (analogous to written and verbal languages) that all machines on the Internet must know so that they can communicate with one another. IP is a layer 3 (network layer) protocol in the OSI model. The vast majority of IP devices today support IP version 4 (Ipv4) defined in RFC-791, although support for IP version 6 (Ipv6, RFC-2460) is increasing. Internet Protocol Security (IPsec) A collection of Internet standards for protecting IP packets with encryption and authentication. Internet Service Provider (ISP) A company that sells Internet access. Internet Signaling Transport Protocol (ISTP) A PacketCable protocol used by PacketCable PSTN Signaling Gateways. Inter Satellite Link - ISL Download 2.22 Mb. Share with your friends:
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