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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Important Properties

Applications

Acousto-optic modulators find many applications:

They are used for Q switching of solid-state lasers. The AOM, called Q switch, then serves to block the laser resonator before the pulse is generated. In most cases, the zero-order (not diffracted) beam is used under lasing conditions, and the AOM is turned on when lasing should be prohibited. This requires that the caused diffraction losses (possibly for two passes per resonator round trip) are higher than the laser gain. For high-gain lasers (for example, fiber lasers), one sometimes uses the first-order diffracted beam under lasing conditions, so that very high resonator losses result when the AOM is turned off. However, the losses in the lasing state are then also fairly high.
AOMs can also be used for cavity dumping of solid-state lasers, generating either nanosecond or ultrashort pulses. In the latter case, the speed of an AOM is sufficient only in the case of a relatively long laser resonator; an electro-optic modulator may otherwise be required.
Active mode locking is often performed with an AOM for modulating the resonator losses at the round-trip frequency or a multiple thereof.
An AOM can be used as a pulse picker for reducing the pulse repetition rate of a pulse train, e.g. in order to allow for subsequent amplification of pulses to high pulse energies.
In laser printers and other devices, an AOM can be used for modulating the power of a laser beam. The modulation may be continuous or digital (on/off).
An AOM can shift the frequency of a laser beam, e.g. in various measurement schemes, or in lasers which are mode-locked via frequency-shifted optical feedback.
In some cases one exploits the effect that the diffraction angle depends on the acoustic frequency. In particular, one can scan the output beam direction (at least in a small range) by changing the modulation frequency.

Important Properties

Various aspects can be essential for the selection of an acousto-optic modulator for some application:

The material should have a high transparency at the relevant wavelengths, and parasitic reflections should be minimized e.g. with anti-reflection coatings.
In many cases, a high diffraction efficiency is important. For example, this matters when using the AOM as a Q switch in a high-gain laser, and even more so for cavity dumping.
The required RF power influences both the electric power demands and cooling issues.
The switching time is critical for some applications.
For frequency shifters, the device often has to be used in a wide range of RF frequencies.
High optical peak powers require a suitable material and a large open aperture, allowing for a high damage threshold.

Due to various trade-offs, quite different materials and operation parameters are used in different applications. For example, the materials with highest diffraction efficiencies are not those with the highest optical damage threshold. A large mode area can increase the power handling capability, but requires the use of a larger crystal or glass piece and a higher drive power, and also increases the switching time, which is limited by the acoustic transit time. For fast acousto-optic beam scanners, a large mode area is required for achieving a high pixel resolution, whereas a smaller mode area is required for a high scanning speed.

ACPR

Adjacent Channel Power Ratio; a measurement of the amount of power in the adjacent frequency channel. ACPR is usually defined as the ratio of the average power in the adjacent frequency channel to the average power in the transmitted frequency channel. It describes the amount of power generated in the adjacent channel due to nonlinearities in RF components. The ACPR measurement is part of the UMTS standard but is not a part of the cdmaOne standard. (Telecom ABC)
ACR

Adjacent Channel Rejection; the measure of how well a receiver can receive the transmitted signal in the presence of a high-level interfering signal in the adjacent channel. It is measured as a frame error ratio (FER) or packet error rate (PER) at specified interferer power levels. (Agilent)
ACRR

Adjacent Channel Rejection Ratio; the ratio of the average power in a specific offset frequency to the average power in the transmitted frequency. (BarryYuen)
Active

A device or circuit capable of some dynamic function, such as amplification, oscillation, or signal control, and which usually requires a power supply for operation. (Arris Glossary of Terms) Also, in computer parlance, a service flow is said to be “active” when it is permitted to forward data packets. A service flow must first be admitted before it is active.
Active Circuit
Powered circuitry containing transistors, such as amplifiers, power supplies or converters.

Active Satellite

A functioning satellite that receives and transmits or retransmits radio-communication signals to or from a base station. (Timbercon)
Active Service Flow
An admitted Service Flow from the Cable Modem (CM) to the Cable Modem Termination System (CMTS) which is available for packet transmission.

ACTS

Advanced Communications Technology Satellite; a NASA experimental satellite project to demonstrate the use of the Ka-Band (30/20 GHz) services. (Satnews)

Ad Avails

Advertising spots available to a cable operator to insert local advertising on a cable network.

Adapter

A fitting used between two sets of equipment to provide a transition from one to another when they cannot be directly interconnected.
Adaptive Smart Antenna
Combines multiple antenna elements with signal processing algorithms to optimize its radiation and/or reception pattern automatically in response to the signal environment.

Adaptive Timeout

Retry with exponential timeout: first attempt — 1 sec and the last attempt — 16 sec.

Additional Call Offering (ACO)

An ISDN feature that allows multiple calls to be placed simultaneously to the same telephone number. A serving switch is programmed with the number of lines on the receiving telephone equipment. The switch will offer an additional call if there is a line available to accept it. Sometimes erroneously called FCO or Flexible Call Offering.

Address

The number dialed by a calling party which identifies the party called. Also a location or destination in a computer program.

Address Resolution Protocol (ARP)

A protocol of the IETF for converting network (IP) addresses to 48-bit Ethernet addresses.

Addressable

Able to signal from the headend or hub in such a way that only the desired subscriber's receiving equipment is affected. In this way, it is possible to send a signal to a single subscriber and effect changes in the subscriber's level of service.

ADI

Area of Dominant Influence; in the measurement of television audience data, geographic area composed of all the counties influenced by originating stations in a particular television market. For example, the New York City ADI is composed of all the counties in New York and New Jersey where the New York City television stations are viewed. Each county in the United States is allocated exclusively to one ADI. (All Business)
Adjacent Channel
Any of two TV channels are considered adjacent when their view carriers, either off-air or on a cable system, are 6 MHz apart. FM signals on a cable system, two channels apart are adjacent when their carriers are 400 to 600 kHz apart. The channel (frequency band) immediately above or below a specific channel. (Arris Glossary of Terms)
Adjacent Channel Rejection (ACR)

The measure of how well a receiver can receive the transmitted signal in the presence of a high-level interfering signal in the adjacent channel. It is measured as a frame error ratio (FER) or packet error rate (PER) at specified interferer power levels. A sampling of standards that specify ACR:

IEEE Std 802.15.4™-2006, Specific requirements--Part 15.4: Wireless MAC and PHY Specifications for Low-Rate WPANs
IEEE Std 802.11b-1999, 16 September 1999, Paragraph 18.4.8.3, Receiver adjacent channel rejection
IEEE Std 802.11a-1999, 16 September 1999, Paragraph 17.3.10.2, Adjacent channel rejection
ANSI/IEEE Std 802.11 First Edition 1999-00-00, Receiver adjacent channel rejection
NTC TS 003 – 2548, “Radiocommunication Equipment Used in Aeronautical Mobile Services in the VHF Frequency Band”, Technical Standards for Telecommunication Equipment , Office of the National Telecommunications Commission, 87 Phahon Yothin 8 Road, Samsennai, Phayathai, Bangkok 10400, www.ntc.or.th

The adjacent channel rejection (ACR) measurement is very important because it tells you how well your device will perform under real-world conditions. The alternate channel rejection test is very similar to this test. The test setup, according to the IEEE standards, must have two independent signal sources for the in-band and the adjacent channel signals. The two signal sources cannot be coherent in either phase or frequency. You will need a signal combiner for the test signals. It is recommended that you use an isolator for each source in order to avoid injection locking. (Agilent)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\acr diagram_ti_fig5.jpg$

ACR Diagram courtesy of Peder Rand, Texas Instruments (TI), EE Times, 04Aug08, “What's Required for RF4CE?” http://www.eetimes.com/design/microwave-rf-design/4018987/What-s-Required-for-RF4CE-?pageNumber=1

Adjacent Channel Rejection Ratio (ACRR)

The ratio of the average power in a specific offset frequency to the average power in the transmitted frequency. (BarryYuen)
Admitted
A service flow is said to be “admitted” when the Cable Modem Termination System (CMTS) has reserved resources (e.g., bandwidth) for it on the Data Over Cable Service Interface Specification (DOCSIS®) network.
Admitted Service Flow
A Service Flow, either provisioned or dynamically signaled, which is authorized and for which resources have been reserved but is not active.

ADS

Advanced Design System; electronic design automation (EDA) software for high-frequency and high-speed system, modeling, and RF circuit design applications, sold by Agilent® Technologies under the moniker “EEsof® EDA”. (Agilent Technologies)
ADSL
Asymmetric Digital Subscriber Line

Advanced Television (ATV)

Digital television technology that provides better audio and video quality than the analog NTSC standard television Broadcast system. High Definition TV (HDTV) is a form of ATV. (Timbercon)
Advanced Television Enhancement Forum (ATVEF)
A consortium of broadcast, cable and computer companies founded in 1998 that developed the ATVEF Enhanced Content Specification, an HTML and JavaScript- based format for adding content to interactive TV. ATVEF closed at the end of 1999 and turned over the specification to the ATV Forum and SMPTE, an industry alliance of companies that has defined protocols for Hypertext Markup Language (HTML)-based enhanced television, which allow content creators to deliver enhanced programming to intelligent receivers.

Advanced Television System Committee (ATSC)

An organization founded in 1983 to research and develop a digital TV standard for the U.S.; an international organization of 200 members that is establishing voluntary technical standards for advanced television systems.

Aerial

A device from which radio waves are transmitted and received. There are different designs in operation. A metallic rod or wire for sending and receiving radio waves or microwaves. Also referred to as an antenna. (TETRA)

Aerial Cable

Cable suspended in the air on poles or other overhead structures. Usually implies the use of a “messenger strand” to which the cable is lashed for support. (Arris Glossary of Terms)
Aerial Plant
Cable that is suspended in the air on telephone or electric utility poles.

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Aerial Plant Illustration courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

AES
Advanced Encryption Standard
AETN

American Embassy Television Network
AF

Audio Frequency
AFC

Automatic Frequency Control
Affiliate

A broadcast station that airs a network. (Timbercon)
AGC

Automatic Gain Control; a process or means by which gain is automatically adjusted in a specified manner as a function of input level or another specified parameter. (FiberOpticsInfo)

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AGC Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

AGC Threshold
The level of input current, voltage, or RF power at which the automatic gain control (AGC) circuit becomes active.
AGC Time Constant
The amount of time it takes to achieve the required AGC level; also the amount of time it takes to recover from AGC.

Agenda Item

At the FCC, a term that refers to the document which is to be voted on by the Commission at an agenda meeting. The final document is released to the public the same day or as soon as possible. (Timbercon)
Aggregator

Any person or business that, in the normal course of business, provides a public telephone for the use of patrons through an Operator Service Provider (OSP). (Timbercon)
Agile Component

A component which can be tuned to any desired channel. (Channel Vision)
AGL

Above Ground Level
AGNIR

The Advisory Group on Non-Ionizing Radiation (AGNIR) is an independent advisory group of experts. Until April 2005 it reported to the Board of the NRPB; it now reports to a subcommittee of the HPA that is concerned with radiation, chemical and environmental hazards. (TETRA)

AI

Artificial Intelligence

AIT

Application Information Table
Albedo

The ratio of the amount of electromagnetic energy reflected by a surface to the amount of energy incident upon it, often expressed as a percentage. Example: the albedo of the Earth is 34 percent. Also, the reflectivity of a body as compared to that of a perfectly diffusing surface at the same distance from the Sun, and normal to the incident radiation. Albedo may refer to the entire solar spectrum or merely to the visible portion. (Timbercon)earthobservatory.nasa.gov540 × 313 - Global Albedo : Image of the Day

earthobservatory.nasa.gov

540 × 313 - Global Albedo : Image of the Day

earthobservatory.nasa.gov

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\modis_albedo.jpg$

Global albedo image courtesy of http://earthobservatory.nasa.gov/IOTD/view.php?id=2599

ALC

Automatic Level Control
Algorithm
An automatic signal-processing strategy that varies the way in which multiple antenna elements are employed as a function of operational scenarios.

Alignment

Adjustment to predefined parameters, conditions or levels.
Allocations
The assignments of frequencies by the FCC for various communications uses (e.g., television, radio, land-mobile, defense, microwave, etc.) to achieve fair division of the available spectrum and minimize interference among users.

AllVid

In April 2010, the FCC opened a Notice of Inquiry (NOI) on the concept of AllVid, an adapter viewed as a possible successor to the troublesome CableCARD™ (a manifestation of OpenCable Applications Platform, OCAP™, and related to the tru2Way concept). The Commission has lots of ideas on how these gadgets could bridge the gap between smart broadband-connected video devices and the managed networks of cable MSOs, telcos, and satellite-TV operators. The 28-page NOI is a starting point (a formal rulemaking proposal is sure to follow), but the FCC has made it clear that it wants multichannel video programming distributors (MVPDs) to be prepared to offer AllVid equipment to customers by Dec. 31, 2012. The FCC's hope is that AllVid could help unleash a competitive retail market for set-top boxes that tap MVPDs” as well as Web-sourced video. (See “FCC Inches Towards Net-Agnostic Gateways”.) The NOI invites comments about how this can be done, but the FCC already has its own ideas, outlined in the NOI. The AllVid vision starts off with two AllVid product concepts: (1) a small, cheapo set-back adapter to serve as the go-between that could be leased by service providers, and (2) a brainy retail-focused, gateway product that would conceivably open the door to innovation from the consumer electronics industry. The whole-home gateway configuration should be capable of providing "at least six simultaneous video streams" for handling picture-in-picture in three different rooms, according to the FCC's NOI. The FCC expects to consider other "superior configurations," however. Still, there's already one analysis holding that AT&T Inc. (NYSE: T)'s current streaming capabilities for the U-verse TV service would fall short of the FCC's initial AllVid gateway expectations. AllVid would replace the CableCARD™ and handle tuning and security functions that are specific to the MVPD. As conceived, that would leave the "smart video device" to do the cooler stuff -- navigation, presentation of interactive program guides, and search. The FCC is also using the NOI to invite "any alternative proposals”. The FCC doesn't think tru2way should be part of any mandated alternatives. "We are not convinced that the tru2way solution will assure the development of a commercial retail market as directed by Congress," the FCC said, noting a view that tru2way is "an unworkable solution for DBS and other non-cable providers." Cable has appealed to the telcos to adopt tru2way, but those pleas have fallen on deaf ears. (See “Telcos: Climb Aboard the Tru2way Train” and “Verizon: No Way on tru2way”.) The FCC doesn't like the licenses tied to tru2way, and it believes agreements tied to tru2way use and adoption limit a device's ability to feed in video from the Web and to use interfaces from outside parties. (CableLabs officials have countered by saying tru2way can adopt IP profiles, and companies such as Related Content Database Inc. (RCDb) has developed server systems that can bridge Web-sourced video to tru2way devices, so this fight isn't over.) (See “Rogers Seeks Tru2way Alternative”.) The FCC is hoping AllVid leads to a "nationwide interoperability standard, much as Ethernet and the IEEE 802.11 standards have" for broadband data networks. It's already recommending that Ethernet be used as AllVid's physical layer, but does invite comment on other approaches, including those based on Multimedia over Coax Alliance (MoCA). "The AllVid concept would follow the broadband approach," the Commission said. "It would place the network-specific functions such as conditional access, provisioning, reception, and decoding of the signal in one small, inexpensive, operator-provided adapter." It's also looking at DTCP-IP for encryption and authentication, is open to TiVo Inc. (Nasdaq: TIVO)'s suggestion that Universal Plug and Play protocols be used for service discovery, and wonders if over-the-air digital tuners should be baked into AllVid products. Other AllVid questions to be vetted include the role of downloadable security, and how third-party user interfaces can be made to access MVPD services. The FCC thinks the set-back, dongle-like adapter could be as small as a deck of cards, so this product might end up looking like the next-generation Digital Terminal Adapter (DTA) that Comcast Corp. (Nasdaq: CMCSA, CMCSK) has specified and that Huawei Technologies Co. Ltd. showed off at the Society of Cable Telecommunications Engineers (SCTE) Cable-Tec Expo in Denver last fall. (See “Trident Pokes at Broadcom's DTA Chip Lead”.) (Baumgartner)
Alternative Access Provider
A telecommunications firm, other than the local telephone company that provides a connection between a customer's premises to a point-of-presence of the long distance carrier.

Alternate Channel Interference

Interference caused by a signal in the channel beyond an adjacent channel. (Arris Glossary of Terms)
Alternating Current (AC)

An electric current which continually varies in amount, and reverses its direction periodically. The plot of current versus time is usually a sine wave.
Aluminum Sheath Cable

A cable with a solid copper or copper-clad aluminum center conductor, dielectric insulation, and an aluminum shield.
American National Standards Institute (ANSI)
A US standards body. Link: http://www.ansi.com.

AM (Amplitude Modulation)

A technique for sending information as patterns of amplitude variations of a waveform or signal. (Arris Glossary of Terms)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\am-modulation.gif$

AM Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Amateur Radio Operator (HAM)

A noncommercial, private radio operator. There are six classes of amateur radio licenses that can be earned after passing FCC-administered examinations. (Timbercon)
Ambient Temperature

Room temperature
American Standard Code for Information Inter exchange (ASCII)

ASCII is a uniform code used in computer and data communications systems. ASCII code letters, numbers, punctuation and actual control systems in Digital codes of "0s" and "1s." For example, the capital "C" is 100011 and a "3" is 0110011. (Timbercon)
AML

Amplitude Modulated Link; a registered trademark for microwave equipment that is manufactured by Hughes Communication Products Company.
Ampere

A standard unit of measure for current, designated as the amount of current that occurs when one volt is applied across one ohm of resistance.
Amplitude Modulation
The process of impressing information on a radio frequency signal by varying its amplitude. Generally, amplitude modulation is used for the purpose of relaying messages by voices, television, facsimile or other modes.

Amplification

The act of increasing the amplitude or strength of a signal.
Amplified Spontaneous Emission (ASE)

A background noise mechanism common to all types of erbium-doped fiber amplifiers (EDFAs). It contributes to the noise figure of the EDFA which causes loss of signal-to-noise ratio (SNR). (FiberOpticsInfo)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\ase.gif$

ASE Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Amplifier

A device which increases the power and/or amplitude of an electrical signal. Amplifiers are placed where needed in a cable system to strengthen signals weakened by cable and component attenuation. Two-way single-cable systems use a forward and a reverse amplifier inside one enclosure to boost signals traveling in both directions. (Arris Glossary of Terms)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\amplifier.gif$

Amplifier Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Amplifier Spacing

The spacing in transmission loss, expressed in decibels, between cascaded, or serially connected, amplifiers. Also sometimes used to denote the linear cable distance between amplifiers in a system. (Arris Glossary of Terms)

Amplitude

The distance between the high and low points of a wave-form or signal; the strength of a signal.
AN
Access Node

Analog
In telecommunications, analog refers to a transmission standard that uses variable frequencies and amplitudes of electrical impulses to emulate the audio waveform of sound. An analog telephone line is referred to as a Plain Old Telephone Service (POTS) line. Traditional form of telecommunications transmission in a constant variable wave, rather than in packet-based (or digital) form. See also Modem and Digital. Analog signals have a frequency and bandwidth measured in Hertz.

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\analog.gif$

Analog Waveform courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Analog Device
A device that operates with variables represented by continuously measured quantities such as voltages, resistances, rotations, and pressures.

Analog QAM

Analog QAM uses two carriers 90 degrees out of phase with each other. Each carrier is modulated by an analog signal, and the resulting modulated waves are combined.

Analog Signal

A signal that is solely dependent on magnitude to express the information content.

Analog-to-Digital

A device that converts a signal whose input is information in the analog form and whose output is the same information in digital form.

Angular Misalignment

Loss at a connector due to fiber end face angles being misaligned. (FiberOpticsInfo)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\angular_mis.gif$

Angular Misalignment Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Angular Mismatch

See Axial Alignment Loss
Angular Response

A lensed photo detector (PD) specification describing the incident angle of light received by the PD at which PD sensitivity is reduced to 50% of its maximum rating. (Zanger)
Anode

The opposite of a cathode, and may be an integral part of a Cathode Ray Tube (CRT). The positively charged anode attracts the stream of negatively charged electrons and compacts them into a compressed beam. A second anode then accelerates them, and the electron beam is then ready to be projected at the phosphor display screen. (Glossary of Terms dot Net)
Antenna
A structure or device used to receive or transmit electromagnetic waves.

Antenna Array

A group of identical antennas arranged and interconnected for achieving greater directivity (gain) or beam shaping.

Antenna Efficiency

The ratio of the total radiated power to the total input power. Note: The total radiated power is the total input power less antenna dissipative losses. (ATIS)
Antenna Gain

The ratio, expressed in decibels, of the signal level received or transmitted by an antenna, to the signal level received or transmitted by an isotropic antenna at that same location which is subject to the same power level. (Arris Glossary of Terms)
Antenna Preamplifier
A small amplifier, usually mast-mounted, for amplifying weak signals to a level sufficient to compensate for down-lead losses and to supply sufficient input to system control devices.

Antenna Stack

Antenna tower with multiple antennas and supports.

Anti-Siphoning

FCC rules which prevent cable systems from “siphoning off” programming for pay cable channels that otherwise would be seen on conventional broadcast TV. “Anti-siphoning” rules state that only movies no older than three years and sports events not ordinarily seen on television can be cablecast.

APC

Angled Physical Contact; a style of fiber optic connector with a 5 -15 angle on the connector tip for the minimum possible backreflection. (FiberOpticsInfo)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\apc-endface.gif$

APC Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

APD

Avalanche Photodiode
Aperture

A cross sectional area of the antenna which is exposed to the satellite signal. (Satnews)
API
Application Program Interface

APL

Average Picture Level; a video quality parameter. (FiberOpticsInfo)
Apogee

The point in an elliptical satellite orbit which is farthest from the surface of the earth. Geosynchronous satellites which maintain circular orbits around the earth are first launched into highly elliptical orbits with apogees of 22,237 miles. When the communication satellite reaches the appropriate apogee, a rocket motor is fired to place the satellite into its permanent circular orbit of 22,237 miles. (Satnews)
Apogee Kick Motor (AKM)

Rocket motor fired to circulate orbit and deploy satellite into geostationary orbit. (Satnews)
Application
An application is a functional implementation realized as software running in one or spread over several interplaying hardware entities.

Application Boundary

A concise general description of the data elements (HTML documents, code files, images, etc.) used to form one application and the logical locator of the entry point, the application boundary is described by a regular expression over the URL language. Where no such boundary is drawn, the default boundary shall be the entire set of documents that the OpenCable™ platform can access.

Application Information Table (AIT)

Provides information about the activation state of service-bound applications.

Application Manager

The application manager is the entity in the OpenCable Platform responsible for managing the lifecycle of the applications. It manages both bound and unbound applications.

Application Platform

An application platform is the collection of application program interfaces and protocols on which content and applications are developed.

Application Program Interface (API)

An application program interface is the software interface to system services or software libraries. An API can consist of classes, function calls, subroutine calls, descriptive tags, etc.

APSIS

Adaptive Power System Interface Specification; under the auspices of the Sustainability Management Subcommittee (SMS), SCTE aims to create a “critical facility” focused specification titled “Adaptive Power System Interface Specification” (APSIS). The Sustainability Management Subcommittee (SMS) was formed within SCTE and crosses wired broadband industry boundaries (NCTA, CableLabs®, CENELEC, EU, OEMs). SMS is tasked in the relative short term (CYs 2011 and 2012) to create a set of meaningful requirements documents modeled after Telcordia specifications that will improve cable industry energy usage efficiency. SMS activities today are focused on specifications impacting energy usage within “critical facilities” including headends (HEs), super HEs, and hubs. Why now you might ask. Today’s typical HFC network HE consumes two (2) to three (3) million watts of electricity (i.e., 2 to 3 MW-hours) and operates with virtually no consideration of delivering subscriber content efficiently with a “bits delivered per $ or Euro” metric in mind.
APSIS efforts were launched 15 September 2011 with initial standard to be available for review in the July 2012 timeframe.
The APSIS concept requires various types of technology, existing and new, embedded within next generation products and added to existing products that permit intelligent delivery of digital bits to subscribers at lower delivered cost per bit, such as:

High linearity, high peak voltage swing capable GaN and other III-V compound semiconductor based die enabled amplifiers operating from +8 to +90 Vdc in future HEs, hubs, downstream laser transmitters, MDU_MTU_xMATV applications (including R-ONUs, ONTs, SANs, and residential gateways).
Modules, MMICs, and die with embedded digital, analog, and mixed signal control interface power detection (Pdetect) capabilities. ‘Pdetect’ includes peak, average, RMS, envelope, envelope tracking, and other power measurement, storage, alarm, and reporting capabilities.
As above with power down (Pdown) and power fold-back (Pfb) capabilities.
As above with embedded tilt, attenuation, and cable simulation (“Bode filter”) capabilities.
As above with embedded gain control capabilities.
As above with “Test I/O” capabilities.

FIGURE. Diagram of Proposed APSIS Specifications Applied to Typical Wired Broadband Industry Headend (HE) with Estimated Energy Savings (courtesy of Conrad Young)

Apstar

Asia-Pacific Star; name of the Chinese satellite system which carries commercial video services in the region. (Satnews)
Arabsat

Arabsat Satellite Organization; headquartered in Riyadh, Saudi Arabia. It provides regional telecommunications services for the Middle East region. (Satnews)
AR Coating

Antireflection Coating; a thin, dielectric or metallic film applied to an optical surface to reduce its reflectance and thereby increase its transmittance. (FiberOpticsInfo)
Armor

A protective layer, usually metal, wrapped around a cable. (FiberOpticsInfo)
Armored Cable

Coaxial cable that can be direct buried without protective conduit or used in underwater applications. This type of cable is constructed with a flooding compound applied to the cable's outer shield, followed by plastic jacketing, steel armor and flooding compound, and an additional plastic jacket. (Arris Glossary of Terms)
ARP
Address Resolution Protocol

ARPU

Average Revenue per Unit

ASD

Authorized Service Domain

AsiaSat

A satellite system covering the Asia mainland. (Satnews)
ASC

Automatic Slope Control
ASCII

American Standard Code for Information Interchange; an encoding scheme used to interface between data processing systems, data communication systems, and associated equipment.
ASIC

Application-Specific Integrated Circuit; a custom-designed integrated circuit. (FiberOpticsInfo)

Aspect Ratio

The aspect ratio refers to the ratio of width to height of a picture. Standard definition television uses a 4:3 aspect ratio. High definition television uses a 16:9 aspect ratio.
ASTM

American Society for Testing and Materials; an organization that provides a forum for the development and publication of voluntary consensus standards for materials, products, systems, and services that serve as a basis for manufacturing, procurement, and regulatory activities. (FiberOpticsInfo)
Asymmetric Connection
A connection where data can flow in one direction at a much higher speed than in the other. Some examples of asymmetric connections are ADSL, 56K Modems, and satellite downlinks. See also Back Channel.

Asymmetric Digital Subscriber Line (ADSL)

A data communications technology that can “piggyback” a standard voice telephone connection and a high-speed (up to 8Mbps) digital data link on to a single pair local loop connections to a customer premises. ADSL technology is an asymmetric technology, meaning that the speed of the digital link to a customer premises is generally not the same speed as the connection coming back. With ADSL, for example, a customer may have only 128Kbps of outbound bandwidth, but may be able to receive data at speeds of 8Mbps. See also DSLAM, NID, and xDSL.

Asymmetric Key

An encryption key or a decryption key used in public key cryptography, where encryption and decryption keys are always distinct.

Asynchronous

A type of transmission in which each character is transmitted independently without reference to a standard clock; uses stop and start bits.

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Asynchronous_Synchronous Waveforms courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Asynchronous Communications

Stream of data routed through a network as generated, rather than in organized message blocks. Most personal computers send data in this format. (See ATM) (Satnews)
Asynchronous Transfer Mode (ATM)
The transfer mode in which the information is organized into cells. It is asynchronous in the sense that the recurrence of cells containing information from an individual user is not necessarily periodic. Or a protocol for the transmission of a variety of digital signals using uniform 53-byte cells.

Asynchronous Transmission Protocol

A method of encoding a data transmission that places start and stop sequences at the beginning and end of each byte, instead of at the beginning and end of each larger block of data sent. This increases the “overhead” required to transmit each byte and decreases throughput. See also Synchronous Transmission Protocol.

ATE

Automatic Test Equipment; test equipment computer programmed to perform a number of test measurements on a device without the need for changing the test setup. Especially useful in testing components and PCB assemblies. (FiberOpticsInfo)
ATM
Asynchronous Transfer Mode
ATM Cell
A digital information block of fixed length (53 octets) identified by a label at the ATM layer.

ATP

Acceptance Test Plan

ATSC

Advanced Television System Committee; formed to establish technical standards for advanced television systems, including digital high definition television (HDTV). (FiberOpticsInfo)

ATSC M/H

Advanced Television Systems Committee - Mobile/Handheld is a standard in the USA for mobile digital TV allowing TV broadcasts to be received by mobile devices.

Just as the DVB-H and 1seg are mobile TV extensions to the DVB-T and ISDB-T terrestrial digital TV standards respectively, ATSC-M/H is an extension to the available digital TV broadcasting standard ATSC A/53. ATSC is optimized for a fixed reception in the typical North American environment and uses 8VSB modulation. The ATSC transmission scheme is not robust enough against Doppler shift and multipath radio interference in mobile environments, and is designed for highly directional fixed antennas. To overcome these issues, additional channel coding mechanisms are introduced in ATSC-M/H to protect the signal. (Whitaker, ATSC-Mobile DTV Standard)

Attenuation
The decrease in amplitude of a signal between any two points in a circuit, usually expressed in decibels (dB). Also, the decrease in signal strength along a fiber optic waveguide caused by absorption and scattering. Optical waveguide, fiber optic cable, twisted pair, and coaxial cable attenuation is usually expressed in dB/km. (FiberOpticsInfo)

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Fiber Optic Waveguide Attenuation Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Attenuation Coefficient

The rate of diminution of average power with respect to distance along a transmission path. Note: The attenuation coefficient is often calculated as the sum of the absorption coefficient and the scattering coefficient. Synonym attenuation rate. (ATIS)
Attenuation-limited Operation
The condition in a fiber optic link when operation is limited by the power of the received signal (rather than by bandwidth or distortion). (FiberOpticsInfo)
Attenuator

A device, passive or active, which reduces the amplitude of a signal.
Attitude Control

The orientation of the satellite in relationship to the earth and the sun. (Satnews)
ATV Forum
The Advanced TV Forum is a membership association founded in 2000 that promotes interactive TV. It supports the Enhanced Content Specification originally developed by the Advanced Television Enhancement Forum (ATVEF).

ATVEF

Advanced Television Enhancement Forum

Audio

Relating to sound or its reproduction; used in the transmission or reception of sound.

Audio Frequency

That range of frequencies lying within the range of human hearing, approximately 20 to 20,000 Hz.
Audio Server
An Audio Server plays informational announcements in PacketCable network. Media announcements are needed for communications that do not complete and to provide enhanced information services to the user. The component parts of Audio Server services are Media Players and Media Player Controllers.
Audio Subcarrier

The carrier wave that transmits audio information between 5 and 8.5 MHz on a satellite broadcast. (Arris Glossary of Terms)

Aural Subcarrier

A subcarrier that serves as a control signal for use in the reception of FM stereophonic sound broadcasts. [47 CFR 73.310] Also, a subcarrier used in the reception of TV stereophonic aural or other subchannel broadcasts. [47 CFR 73.681]. Also referred to as a Pilot Subcarrier. (ExpertGlossary)
Authentication
The process of verifying the claimed identity of an entity to another entity.
Authenticity
The ability to ensure that the given information is without modification or forgery and was in fact produced by the entity that claims to have given the information.

Authorization

The act of giving access to a service or device if one has permission to have the access.

Authorization Module

The authorization module is an abstract module that the Cable Modem Termination System (CMTS) can contact to authorize Service Flows and Classifiers. The authorization module tells the CMTS whether the requesting Cable Modem (CM) is authorized for the resources it is requesting.

Automatic Frequency Control (AFC)

A circuit that locks onto a chosen frequency and will not drift away from that frequency.
Automatic Gain Control (AGC)
A circuit which automatically controls the gain of an amplifier so that the output signal level is virtually constant for varying input signal levels.

Automatic Level Control (ALC)

The automatic adjusting of signal levels in a system.
Automatic Slope Control (ASC)
Circuitry which permits amplifier response compensation for varying slope (tilt) at its input.

Avail

Slang for opportunity in video content where ad may be sold. (Fain)
Availability
In cable television systems, availability is the long-term ratio of the actual RF channel operation time to scheduled RF channel operation time (expressed as a percent value) and is based on a bit error rate (BER) assumption.

Avalanche Photodiode (APD)

A photodiode that exhibits internal amplification of photocurrent through avalanche multiplication of carriers in the junction region. (FiberOpticsInfo)

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APD Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

AVC
Advanced Video Coding
Average Power

The average level of power in a signal that varies with time. (FiberOpticsInfo)
Average Revenue per Unit (ARPU)
Commonly used a financial benchmark in the cable industry to measure average revenue per cable subscriber.
Average Session Length

A measure of the typical length of a viewing session for a particular site over a period of time. (Fain)
AWG

Arrayed Waveguide Grating, a device built with silicon planar lightwave circuits (PLC) that allows multiple wavelengths to be combined and separated in a dense wavelength-division multiplexing (DWDM) system. (FiberOpticsInfo)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\awg-construction.gif$

Arrayed Waveguide Grating (AWG) Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

AWT
Abstract Windowing Toolkit

Axial Alignment Loss (Angular Mismatch)

Axial alignment loss is the signal loss that occurs when the optical cables are connected at an angle relative to the axis (centerline) of each other. When the optical fibers are at an angle relative to each other, some or all of the light is transmitted from one fiber to the other outside the NA, which does not allow the optical signal to be coupled into the other fiber. Axial Alignment is also called angular mismatch or angular misalignment. The diagram below shows how incorrect axial alignment of fiber optic connectors can cause insertion loss. This diagram shows two optical fibers that are not exactly aligned along their axis (centerline). As a result, some of the optical signal from the fiber ends cannot enter the fiber on the mating connector resulting in loss of signal. (Optical Dictionary)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\ag_optical_connector_loss_axial_alignment_low_res.jpg$

Axial Alignment Diagram courtesy of Optical Dictionary dot com, http://www.opticaldictionary.com/Optical_Dictionary_Connector_Loss_Definition.html

Axial Propagation Constant

For an optical fiber, the propagation constant evaluated along the axis of a fiber in the direction of transmission. (FiberOpticsInfo)
Axis

A straight line, real or imaginary, passing through a body and indicating its center; a line so positioned that various portions of an object are located symmetrically in relation to the line. (Photonics dot com) Also, the center of an optical fiber. (FiberOpticsInfo)

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\axis_fiber-axis.gif$

Optical Fiber Axis Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/a

Azimuth

Degrees of rotation clockwise from true north.
Azimuth-Elevation (Az El) Mount

An antenna mount which tracks satellites by moving in two directions: the azimuth in the horizontal plane and elevation up from the horizon.

B:

B Channel

An ISDN B Bearer channel can be used to carry voice or data connections at speeds of 56 or 64Kbps.

Back Channel

A back channel is a term that applies to asymmetric data connections. It is the slower of the two data paths, or directions, in the connection. Often times, as with ADSL and 56Kbps modems, the back channel is transmitted over the same set of wires or other media as the larger of the two data paths. In other cases, such as with satellite downlinks and some cable modem systems that use a modem and the telephone system to carry the back channel, the data is returned via a different transmission media.

$c:\users\cyoung\desktop\glossary of terms\drawings_diagrams\backchannel.gif$

Back Channel Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/b

Back Porch
That portion of the composite picture signal which lies between the trailing edge of the horizontal sync pulse and the trailing edge of the corresponding blanking pulse.

Backbone

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