Commonly Used Telecommunication Terms
(with emphasis on Cable Television)

Access channels typically provide community-oriented programming, such as local news, public announcements and government meetings. They are usually programmed by individuals or groups, on either public, educational or governmental access channels or on commercial leased access channels.

Bandwidth

The width or measure of the information-carrying capacity of a communication channel. The bandwidth corresponds to the difference between the lowest and highest frequency signal that can be carried by the channel.

CATV

Community Antenna TeleVision. Also called Cable TV

Cable System

The facility, consisting of a set of closed transmission paths and associated signal generation, reception, and control equipment that is designed to provide cable service which includes video programming and which is provided to multiple subscribers within a community.

Channel

A signal path of specified bandwidth for conveying information.

Channel Capacity

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

Cluster

The group of homes passed by a single fiber node.

Coaxial Cable

Cable with a central copper strand for transmitting electrical signals, surrounded by a concentric air or insulation core, and enclosed by an outer (electrically shielding) concentric metal fiber, either braided or solid.

Converging Technologies

Used to describe the sectors of industry coming together in the deployment of advanced interactive technologies, including: telecommunications, computers hardware, software, and the peripheral companies supporting digital systems, applications, and services that support information and content exchange.

The use of a binary computer code represent information. In cable, digital transmission is much clearer than analog. Digital technology also allows for more information to be processed

Digital Set Top Box

A device which accepts digital encoded television broadcasts and converts them to display on an analog television set.

Distribution system

Part of a cable system consisting of trunk and feeder cables.

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 MCNS, a consortium consisting of CableLabs and a consortium of North American multi-system operators.

(DSL)

Technology providing high speed data rates over conventional phone lines.

Downstream

Signals transmitted to a subscriber. Also referred to as Forward Traffic.

Drop

The cable and hardware from the tap to subscriber.

Drop Cable

Generally 330 feet or less, of coaxial cable, starting at a tap and continuing on to the subscriber's connection.

End user

A person, organization, or telecommunications system that accesses the network in order to communicate via the services provided by the network

The most popular LAN technology in use today. The IEEE standard 802.3 defines the rules for configuring an Ethernet network. It is a 10 Mbps, CSMA/CD baseband network that runs over thin coax, thick coax, twisted pair or fiber optic cable.

Commission (FCC)

The agency that regulates which communications services, including television, at the federal level.

Feeder Cables

The cables that take signals from the trunk line to the subscriber area and to which the subscriber taps are attached.

Feeder line

Cable distribution lines that connect the main trunk line or cable to the smaller drop.

A method of transmitting signals over light waves sent through extremely thin fibers spun from glass.

A contract between a cable television company and a municipal government authorizing the company to install cable and offer cable television service within the community.

(FTTx)

Installation of fiber in the cable or telephony directly to the home or curb.

The control center of a cable television system, where incoming signals are amplified, converted, processed and combined into a common cable along with any original cablecasting, for transmission to subscribers. The system usually includes antennas, preamplifiers, frequency converters, demodulators, modulators, processors and other related equipment

Hertz (Hz)

A unit of frequency equivalent to one cycle per second.

(HDTV)

A very high quality television signal with picture resolution nearly equal to that of film.

The number of homes in which a cable television service is or can be made available by adding a drop to an already existing feeder line.

A signal distribution point for part of an overall system. Larger cable systems are often served by multiple hub sites, with each hub in turn linked to the main headend with a transportation link such as fiber optics, coaxial supertrunk, or microwave.

(HFC)

A network consisting of fiber optical cables and coaxial cables.

(INET)

Generally dedicated to link government and other public buildings for such uses as training, meetings, data and voice.

Cable systems that have the technical ability to let subscribers communicate directly with a computer at the system headend from their television sets, using special converters and the regular cable lines. Viewers are able to order movies and video games, access library information and request sales brochures and coupons from home.

(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.

(ISP)

The companies that provide the access and services linking end users to the Internet and the world wide web.

Expressed in bps (bits per second), the maximum rate at which data can reliably be transmitted over a line using given hardware.

(LAN)

Private transmissions network interconnecting offices within a building or group of buildings, and usually designed to convey traffic (voice, video, data, and facsimile.) Typically includes a computer network made up of computer, printers and mass storage units

An exchange where telephone subscriber lines connects.

(LEC)

A local telephone company within a serving area or LATA

The set of facilities used by a telephone company to transport signals between a central office, roughly similar to a cable TV headend, and a customer location.

(MAN)

A loosely defined term generally understood to describe a data network covering an area larger than a local area network, but less than a wide area network. Usually contained in a city or metropolitan area.

MegaHertz (MHz)

One million cycles per second

Multiple System Operator (MSO)

A company that owns and operates more than one cable system.

Generally refers to delivery channels capable of carrying line speeds less than 1.5 Mbps.

An addressable unit in a network, which can be a computer, work station or some type of communications control

A type of telecommunication service in which the communication path is established almost immediately in response to a user request brought about by means of a user-network signaling Service.

An extremely thin, flexible thread of pure glass, able to carry one thousand times the information possible with traditional copper wire.

Pay Per View (PPV)

Pay television programming which cable subscribers pay a separate fee for each program viewed.

Port

The physical connector on a device enabling the connection to be made.

Cable programming services for which subscribers pay an additional fee above the basic cable service charge. Also called Pay Cable.

A non-commercial channel set aside by a cable system for use by the public, on a first come first serve, non-discriminatory basis.

Analog electrical signals sent over the cable. Conventional (broadcast) television and radio, as well as cable TV, deliver RF signals to your television/radio. RF is quickly becoming yesterday's news to many cable TV providers who are installing fiber-optic lines that will replace today’s cables.

The physical upgrade of a cable system, often involving the replacement of amplifiers, power supplies, passive devices and sometimes the cable, strand, hardware and subscriber unit.

A part of the Network Access which performs application-specific functions such as decoding digital TV.

System Operator

The individual, organization, company or other entity that operates a cable TV system

Take Rate

The ratio of homes that pay for a cable service to homes passed.

Tap

A tap is a device that splits off a portion of the feeder line signal for the subscriber.

Telco

Telephone Company - Refers the local exchange telephone carrier.

Telecommunica-tions

Communicating over a distance through wire, radio, optical or other electromagnetic means.

Television

The electronic transmission and presentation of pictures and sounds.

Cables that carries the signal from the headend to groups of subscribers. Radiating out from the headend are trunk lines that carry the main CATV signal to be distributed.

The term used to describe traffic and paths that go from the subscriber to the headend. Also referred to as Reverse Path or Return Path

A term pertaining to the bandwidth and spectrum of the signal which results from television scanning and which is used to produce a picture.

(VOD)

Allows the end-user subscriber to select movies they wish to view from a large selection of titles and categories stored on a remote server at any time. Service may also provide VCR functionality, (stop, pause etc. which allows the end-user subscriber to control the "play back" of the server from the remote control.

Uses microwaves frequencies to transmit programming to a small antenna at a subscribers home

The assistance of the Office of Information Technology was essential in developing this list. Special Thanks to Lisa Wright and Bob Glaze.

For additional resources on cable television issues, refer to: