An ISDN Data channel is a data connection between the telephone company's switching equipment and its 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.
Source: CableLabs, 9/25/2007  

Unused 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.
Source: CableLabs, 9/25/2007  

The movement of encoded information by means of electrical transmission systems. The transmission of data from one point to another over communication channels.
Source: CableLabs, 9/25/2007  

A technique that saves storage space by eliminating gaps, empty fields, redundancies, or unnecessary data to shorten the length of records or blocks.
Source: CableLabs, 9/25/2007  

Layer 2 in the Open System Interconnection (OSI) architecture; the layer that provides services to transfer data over the transmission link between open systems.
Source: CableLabs, 9/25/2007  

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.
Source: CableLabs, 9/25/2007  

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.
Source: CableLabs, 9/25/2007  

A procedure applied to ciphertext to translate it into plaintext.
Source: CableLabs, 9/25/2007  

A standard by SMPTE (Society of Motion Picture and Television Engineers) formalizing ATVEF.
Source: CableLabs, 9/25/2007  

A procedure applied to ciphertext to translate it into plaintext.
Source: CableLabs, 9/25/2007  

The key in the cryptographic algorithm to translate the ciphertext to plaintext.
Source: CableLabs, 9/25/2007  

The elapsed time between the instant when user information is submitted to the network and when it is received by the user at the other end.
Source: CableLabs, 9/25/2007  

Distortion resulting from non-uniform speed of transmission of the various frequency components of a signal; i.e., the various frequency components of the signal have different times of travel (delay) between the input and the output of a circuit. Also known as Group Delay Distortion.
Source: CableLabs, 9/25/2007  

An effect of multi-path for a digital interface in which multiple reflections of the same signal arrive at the receiver at different times, creating a noticeable degradation in signal quality.
Source: CableLabs, 9/25/2007  

The extraction of the modulation or information from a radio-frequency current.
Source: CableLabs, 9/25/2007  

Breakdown of television viewers by such factors as age, sex, income levels, education and race.
Source: CableLabs, 9/25/2007  

A technology that provides in fiber the equivalent of frequency division multiplexing, in metallic wire. Separate parallel channels are transmitted on a single fiber, with one wavelength for each channel. Current products enable 16 channels of 2.5Gb each for a total of 50Gb per fiber. DWDM can operate over existing single-mode fiber, and therefore reduce upgrade costs. See also Coarse Wavelength Division Multiplexing.
Source: CableLabs, 9/25/2007  

An electronic circuit that restores a scrambled video signal to its standard form.
Source: CableLabs, 9/25/2007  

The photodiode in optical receivers.
Source: CableLabs, 9/25/2007  

Data communication established by a circuit-switched connection over a telephone network. Generally associated with less than broadband speeds (56 kbps or less).
Source: CableLabs, 9/25/2007  

In color TV, the change in gain, expressed in dB, for the 3.58-MHz color sub- carrier as the level of the luminance signal is varied from blanking to white.
Source: CableLabs, 9/25/2007  

Variation in phase of the color sub-carrier of a TV signal as the level of the luminance signal is varied from blanking to white.
Source: CableLabs, 9/25/2007  

A protocol for specifying and controlling network traffic by class so that certain types of traffic get precedence—for example, voice traffic, which requires a relatively uninterrupted flow of data, might get precedence over other kinds of traffic. Differentiated Services is the most advanced method for managing traffic in terms of what is called Class of Service (CoS). Unlike the earlier mechanisms of 802.1p tagging and Type of Service (ToS), Differentiated Services avoids simple priority tagging and depends on more complex policy or rule statements to determine how to forward a given network packet. An analogy is made to travel services, in which a person can choose among different modes of travel—train, bus, airplane—degree of comfort, the number of stops on the route, standby status, the time of day or period of year for the trip, and so forth. For a given set of packet travel rules, a packet is given one of 64 possible forwarding behaviors—known as per hop behaviors (PHBs). A six-bit field, known as the Differentiated Services Code Point (DSCP), in the Internet Protocol (IP) header specifies the per hop behavior for a given flow of packets.
Source: CableLabs, 9/25/2007  

(1) In communications and computer technology, digital refers to a method of encoding information using a binary system made up of zeroes and ones. In communications technology this takes the form of two very different electrical voltages, several volts positive and negative, to represent the two values. This substantial difference in voltages for each state makes it unlikely that minor fluctuations in voltage due to electro-magnetic interference will change the way a signal is interpreted when received. (2) Information that is encoded into bits and bytes, or packets (0s and 1s, computer binary language). Generally perceived to be an advanced communication form offering clearer signals and increased transmission capacity.
Source: CableLabs, 9/25/2007  

A standard by ATSC addressing interactive television.
Source: CableLabs, 9/25/2007  

DAVIC is an international consortium working on the development of standards for interactive television.
Source: CableLabs, 9/25/2007  

A binding between an entity's public key and one or more attributes relating to its identity, also known as a public key certificate.
Source: CableLabs, 9/25/2007  

An engineering technique for converting a cable TV signal into a digital format which may then be processed in a manner that requires a smaller portion of spectrum for its transmission. This compressed format allows many channels to be carried in the bandwidth normally required for one signal. This format can also be easily stored and manipulated.
Source: CableLabs, 9/25/2007  

A European standard governing panEuropean digital mobile telephony. Specified in DVB MHP as a type of return channel network interface for use in receiving and transmitting IP packets.
Source: CableLabs, 9/25/2007  

A switching or transmission facility designed specifically to handle digital signals.
Source: CableLabs, 9/25/2007  

The cable industry has expanded its competitive offerings to include business and residential telephone services delivered over its fiber optic infrastructure. A cable system can offer telephone service over the same cable line that already carries digital video, high-speed Internet and other advanced services to consumers. Cable companies are certified local exchange carriers offering competitive residential voice services across the country.

Many cable companies have launched digital phone service (often known as VoIP -- Voice over Internet Protocol).  Through the use of software, digital phone service provides all of the functionality of the traditional switched telephone network, while making possible new features not available through traditional circuit-switched telephony. Calls are placed over an IP-based data network and voice is transmitted with data "packets."  Facilities-based cable phone service transports these IP data packets over their private managed IP networks with end-to-end quality of service monitoring (while still interconnecting with the public telephone network as necessary).

Related Terms: Voice-over-Internet Protocol (VoIP)
Source: NCTA, 5/15/2009  

The digital splicing of one Moving Pictures Experts Group (MPEG) program (typically a commercial) into another based on digital 'cues' within the MPEG transport stream.
Source: CableLabs, 9/25/2007  

A CableLabs-specified interface over Internet Protocol (IP) that protects cable operators' "harm-to-service" issues. These issues include ensuring that information like emergency alerts and set-up screens are displayed, that there is sufficient bandwidth to deliver the service, that the content is not altered, etc. It also provides commands to enable communication of information between an OpenCable™ unidirectional receiver (OCUR) and a home media server (HMS).
Source: CableLabs, 9/25/2007  

A more generic term [than OpenCable™ unidirectional receiver (OCUR)] for the device on the upstream side of the digital rights interface (DRI). This device receives protected digital content from the cable plant that encodes it with an approved digital rights management (DRM) to distribute it over the digital rights interface (DRI). An OCUR has additional requirements around digital rights management (DRM) change-out, updating, and a few other things that a generic digital rights interface transceiver (DRIT) does not have.
Source: CableLabs, 9/25/2007  

A more generic term [than home media server (HMS)] for the device on the downstream side of the DRI. This device receives protected digital content over the digital rights interface (DRI) interface and may store or present it according to license agreements with the cable operator. The home management system (HMS) has digital rights management (DRM) change-out, updating, and other requirements that the DRIR does not have.
Source: CableLabs, 9/25/2007  

A coding system applied to digital content that manages the usage rights of that content. In order to present the content, the rights specified must be honored by the presenting device. This requirement is usually enforced by attaching the digital rights management (DRM) to encrypted content and protecting the information required to decode the content with keys that can only be obtained by a device authenticated by the DRM.
Source: CableLabs, 9/25/2007  

A device which accepts digital encoded television broadcasts and converts them to display on an analog television set.
Source: CableLabs, 9/25/2007  

A signal that has a limited number of discrete states prior to transmission. This may be contrasted with an analog signal which varies in a continuous manner and may be said to have an infinite number of states.
Source: CableLabs, 9/25/2007  

A data value generated by a public-key algorithm based on the contents of a block of data and a private key, yielding an individualized cryptographic checksum.
Source: CableLabs, 9/25/2007  

A syntax defined in the MPEG-2 standard, part 6, for VCR-like control over a bitstream. Playback commands include Still-Frame, Fast-Forward, Advance, Goto.
Source: CableLabs, 9/25/2007  

High-speed technology to transfer data over an existing twisted-pair copper telephone line. Asynchronous technology (ADSL) provides data transmission rates up to 7 Mbps in one direction, generally within approximately three miles from a telephone central office. See also HDSL and VDSL.
Source: CableLabs, 9/25/2007  

A DSLAM is an xDSL line-interface device located in a telephone company Central Office. One side of a DSLAM connects to customer premises network interface devices (NIDs) over the local loop. The other side interfaces with the PSTN and a wide area (Frame Relay or ATM) network system.
Source: CableLabs, 9/25/2007  

A mode of transmission in which all information to be transmitted is first converted to digital form and then transmitted as a serial stream of pulses. Any signal-voice, data, television-can be converted to digital form.
Source: CableLabs, 9/25/2007  

Licensing authority for DTCP, HDCP and 5C certificates.
Source: CableLabs, 9/25/2007  

Digital video broadcasting is a European standard for digital television.
Source: CableLabs, 9/25/2007  

A specification created by the Digital Display Working Group (DDWG) to accommodate analog and digital monitors with a single connector. There are three different DVI configurations: DVI-A, designed for analog signals, DVI-D, designed for digital signals, and DVI-I (integrated), designed for both analog and digital signals.
Source: CableLabs, 9/25/2007  

Digital Video Recorders, or DVRs, are VCR-like services that capture video programming onto a hard drive located in the set-top box and allow the viewer to pause, fast forward and manage other functions and applications, including the ability to pause live television. See also PVR.
Related Terms: Personal Video Recorder (PVR)
Source: NCTA, 5/15/2009  

An ANSI-sponsored standardization committee of the SCTE.
Source: CableLabs, 9/25/2007  

Satellite technology that transmits directly to the end user or customer. DBS describes a frequency allocation and wide spacing between satellites that generally permits higher-powered transmissions through the air to small 18- to 24- inch receiving facilities located on customer premises (“point-to-multipoint” transport). Also known as direct-to-home (DTH) satellite.
Source: CableLabs, 9/25/2007  

A high-quality tapping device providing isolation between tap and output terminals.
Source: CableLabs, 9/25/2007  

Directionally focused signal transmission from a base station to a remote user made possible by certain smart antenna systems with digital signal processing capabilities; these base stations use information obtained during reception to transmit signals selectively toward certain users and away from others.
Source: CableLabs, 9/25/2007  

The number you dial to reach someone by telephone; a telephone number.
Source: CableLabs, 9/25/2007  

Software controls that allow a Windows program to manage video and sound hardware in a computer. It is usually used for multimedia in games or Web pages running under Windows 95/98 and Windows NT.
Source: CableLabs, 9/25/2007  

A high-gain antenna, shaped like a dish, that is used for the transmission and reception of ultra-high-frequency and microwave signals.
Source: CableLabs, 9/25/2007  

The basic term for software which controls a computer's operation and is loaded from some form of disk, usually a hard drive.
Source: CableLabs, 9/25/2007  

Broadcast TV signals which originate at a point too far away to be picked up by ordinary home reception equipment; also signals defined by the FCC as outside a broadcaster's license area. Cable systems are limited by FCC rules in the number of distant signals they can offer subscribers.
Source: CableLabs, 9/25/2007  

The departure, during transmission and amplification, of the received signal wave form from that of the original transmitted wave form.
Source: CableLabs, 9/25/2007  

A location in a cable television network which performs the functions of a headend for customers in its immediate area, and which receives some or all of its television program material from a master headend in the same metropolitan or regional area.
Source: CableLabs, 9/25/2007  

The hardware of a cable system—amplifiers, trunk cable and feeder lines, attached to utility poles or fed through underground conduits like telephone and electric wires.
Source: CableLabs, 9/25/2007  

The part of a cable television system used to carry signals from the headend to subscriber's receivers. Often applied, more narrowly, to the part of a cable television system starting at the bridger amplifiers.
Source: CableLabs, 9/25/2007  

A telephone company central office switch manufactured by Northern Telecom that has ISDN and other digital telephony capabilities. See also 5ESS.
Source: CableLabs, 9/25/2007  

CableLabs radio-frequency interface specifications for high-speed data-over-cable systems.
Source: CableLabs, 9/25/2007  

The first version of the Data Over Cable Service Interface Specification. DOCSIS 1.0 defines requirements for cable modems and cable modem termination systems that enable broadband Internet access.
Source: CableLabs, 9/25/2007  

The second version of the DOCSIS protocol specification. DOCSIS 1.1 includes an enhanced Media Access Control (MAC)-layer that contains quality of service (QoS) traffic management functions as well as cable modem authentication extensions.
Source: CableLabs, 9/25/2007  

The third version of the DOCSIS protocol specification, developed to significantly increase the upstream data carrying capacity and the robustness to noise and interference. DOCSIS 2.0 includes advanced TDMA and S-CDMA physical layer technologies.
Source: CableLabs, 9/25/2007  

An API for parsing a document and providing a view of the document by constructing a “tree” of objects in memory. The Document Object Model is a platform- and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure and style of documents. The document can be further processed and the results of that processing can be incorporated back into the presented page.
Source: CableLabs, 9/25/2007  

A formal grammar to specify the structure and permissible values of XML documents.
Source: CableLabs, 9/25/2007  

Dolby AC-3 refers to the audio encoding format adopted by the ATSC for its advanced television audio encoding. Also known as Dolby digital.
Source: CableLabs, 9/25/2007  

A server that relates an Internet domain name (such as www.cablelabs.com) to an IP address.
Source: CableLabs, 9/25/2007  

The domain of an Xlet characterizes the space within which the Xlet is able to execute. This includes both the connection where the Xlet is delivered and other connections where an already executing Xlet is allowed to continue executing. An application cannot run outside its domain. The maximum lifetime of an application extends from the moment the user navigates to its domain until the moment that the user navigates away from its domain. In the broadcast case, a connection corresponds to a DVB-service. Broadcast signaling indicates which services can load an application and which services allow an already active application to continue.
Source: CableLabs, 9/25/2007  

Two rapid clicks of the primary (usually left) mouse button, usually performed to launch a program or open a file.
Source: CableLabs, 9/25/2007  

The heterodyning of an input signal with the output of local oscillator, resulting in an intermediate frequency that is lower than the incoming signal frequency.
Source: CableLabs, 9/25/2007  

Transmission of signals from a satellite to a dish or earth station.
Source: CableLabs, 9/25/2007  

The transfer of data from a remote computer, or server, to a local computer. To the Internet user, downloading means to request a copy of a file from another computer and then receive that file.
Source: CableLabs, 9/25/2007  

A message that signals the modules that are part of a DSM-CC object carousel.
Source: CableLabs, 9/25/2007  

Flow of signals from the cable system control center through the distribution network to the customer. For communication purposes, associated with transmission (down) to the end-user. Or in cable television, the direction of transmission from the headend to the subscriber.
Source: CableLabs, 9/25/2007  

The cable and hardware from tap to subscriber is called the drop.
Source: CableLabs, 9/25/2007  

Generally 330 feet or less, of coaxial cable, starting at a tap and continuing on to the subscribers connection. Or coaxial cable that connects to a residence or service location from a directional coupler (tap) on the nearest coaxial feeder cable.
Source: CableLabs, 9/25/2007  

Two independent distribution systems operating side by side, providing double the channel capacity of a single cable.
Source: CableLabs, 9/25/2007  

Telephone “touch” tones. So-called because each keypad button pressed generates a unique combination of two audible tones or frequencies.
Source: CableLabs, 9/25/2007  

In a communications channel, the ability to transmit in both directions.
Source: CableLabs, 9/25/2007  

A DVB-network is a collection of MPEG-2 Transport Stream multiplexes transmitted on a single delivery system. For example, all digital channels on a specific cable system make up a DVB network.
Source: CableLabs, 9/25/2007  

DVB-J refers to the Java platform as defined as part of the DVB-MHP 1.0.1 [9]. For the OCAP 1.0 implementation, DVB-J is part of the execution engine.
Source: CableLabs, 9/25/2007  

DVB-J API refers to one of the Java APIs standardized as part of the DVB-MHP 1.0.1 [9]. For the OCAP 1.0 implementation, the DVB-J APIs are supported in the execution engine.
Source: CableLabs, 9/25/2007  

A DVB-J application is a set of DBV-J classes that operate together and need to be signaled as a single instance to the application manager so that it is aware of its existence and can control its lifetime through a lifecycle interface. DVB-J applications as specified by the DVB-MHP 1.0.1 [9] are not directly supported by OCAP 1.0 without modifications pertaining to this specification.
Source: CableLabs, 9/25/2007  

An Internet protocol used for dynamically assigning network layer (Internet Protocol) addresses to IP hosts.
Source: CableLabs, 9/25/2007  

The ratio between the greatest signal power that can be transmitted over a multichannel analog transmission system without exceeding distortion or other performance limits, and the least signal power that can be utilized without exceeding noise, error rate or other performance limits.
Source: CableLabs, 9/25/2007