GLOSSARY OF TELECOMMUNICATIONS TERMS

ACCESS CHARGE
A fee charged subscribers or other telephone companies by a local exchange carrier for the use of its local exchange networks.

ACCOUNT CODE
Two-digit code associated with an authorization code, identifying the caller.

ANALOG SIGNAL
A signaling method that uses continuous changes in the amplitude or frequency of a radio transmission to convey information.

AUTOMATIC CALL BACK (ACB)
A feature of a communications device or network that records, and can dial, the originating phone number of the last incoming call.

AUTOMATIC CALL DISTRIBUTOR (ACD)
A device that distributes incoming calls to a specific group of terminals. Note: If the number of active calls is less than the number of terminals, the next call will be routed to the terminal that has been in the idle state the longest. If all terminals are busy, the incoming calls are held in a first-in-first-out queue until a terminal becomes available.

AUXILIARY EQUIPMENT
Equipment not under direct control of the central processing unit. Synonym: ancillary equipment.

BACKUP
The provision, logical or physical, of facilities to speed the process of restart and recovery following failure. Facilities may include duplicated files of transactions, periodic dumping of core or backing storage contents, duplicated processors, storage devices, terminals, telecommunications hardware or the switches to effect a changeover.

BANDWIDTH
The capacity of a telecom line to carry signals. The necessary bandwidth is the amount of spectrum required to transmit the signal without distortion or loss of information. FCC rules require suppression of the signal outside the band to prevent interference.

BILLED TELEPHONE NUMBER (BTN)
The "main number" of a customer's service that the LEC uses as a customer's account number. It is usually also an actual ANI. Will generally have WTNs associated with it. Every separate, distinct phone bill a customer gets will generally have a separate BTN.

BROADBAND
Broadband is a descriptive term for evolving digital technologies that provide consumers a signal switched facility offering integrated access to voice, high-speed data service, video-demand services, and interactive delivery services.

BROADBAND
(1) A transmission facility having a bandwidth of greater than 20 kHz and, therefore, capable of higher-speed data transmission. (2) Analog transmission technique used with data and video transmissions that provides multiple channels for users through frequency division multiplexing.

CALLING PARTY PAYS
A billing method in which a wireless phone caller pays only for making calls and not for receiving them. The standard American billing system requires wireless phone customers to pay for all calls made and received on a wireless phone.

CELLULAR TECHNOLOGY
This term, often used for all wireless phones regardless of the technology they use, derives from cellular base stations that receive and transmit calls. Both cellular and PCS phones use cellular technology.

CENTRAL OFFICE (CO)
(1) Location of telephone switching equipment where customers' lines are terminated and interconnected. (2) Switching center that provides local access to the public network. Sometimes referred to as: End Office, Local Dial Office, Wire Center or Switching Center.

CENTREX
A type of private branch exchange service where incoming calls may be dialed direct to extensions without operator assistance. Outgoing and intercom calls may be dialed by extension users.

CHANNEL BANK
(1) A part of the carrier system that performs the first step of modulation. (2) A multiplexer that modulates a group of channels into a higher frequency band and, conversely, demultiplexes the higher frequency band into individual channels. It can break a signal into the equivalent of 24 analog voice grade and/or 56 Kbps digital channels.

CLOSED CAPTIONING
A service for persons with hearing disabilities that translates television program dialog into written words on the television screen.

COMMERCIAL LEASED ACCESS
Manner through which independent video producers can access cable capacity for a fee.

COMMON CARRIER
In the telecommunications arena, the term used to describe a telephone company.

COMMUNICATIONS ASSISTANT
A person who facilitates telephone conversation between text telephone users, users of sign language or individuals with speech disabilities through a Telecommunications Relay Service (TRS). This service allows a person with hearing or speech disabilities to communicate with anyone else via telephone at no additional cost.

COMMUNITY ANTENNA TELEVISION (CATV)
A service through which subscribers pay to have local television stations and additional programs brought into their homes from an antenna via a coaxial cable.

CRAMMING
A practice in which customers are billed for enhanced features such as voice mail, caller-ID and call-waiting that they have not ordered.

CROSSTALK
Transmission noise caused by energy "leaking" from one channel to another on the same facility. [In analog voice communications, crosstalk makes conversation on one circuit accidentally audible on another.]

DEMARC - (DEMARCATION POINT)
The point, jack or cross connect panel, at which ownership or responsibility for operating and maintaining facilities passes from one party to another.

DIAL AROUND
Long distance services that require consumers to dial a long-distance provider’s access code (or "10-10" number) before dialing a long-distance number to bypass or "dial around" the consumer’s chosen long-distance carrier in order to get a better rate.

DIGITAL TELEVISION (DTV)
A new technology for transmitting and receiving broadcast television signals. DTV provides clearer resolution and improved sound quality.

DIRECT BROADCAST SATELLITE (DBS/DISH)
A high-powered satellite that transmits or retransmits signals which are intended for direct reception by the public. The signal is transmitted to a small earth station or dish (usually the size of an 18-inch pizza pan) mounted on homes or other buildings.

DIRECT INWARD DIALING (DID)
A PBX or CENTREX feature in which incoming calls are completed to extensions without the assistance of an operator.

DIRECT INWARD DIALING (DID)
A service feature that allows inward-directed calls to a PBX to reach a specific PBX extension without human intervention.

DUAL TONE MULTIFREQUENCY (DTMF)
Type of signaling which emits two distinct frequencies for each indicated digit. Synonym: push button dialing, touch tone dialing.

E-MAIL
Also called electronic mail, refers to messages sent over the Internet. E-mail can be sent and received via newer types of wireless phones, but you generally need to have a specific e-mail account.

ENHANCED SERVICE PROVIDERS
A for-profit business that offers to transmit voice and data messages and simultaneously adds value to the messages it transmits. Examples include telephone answering services, alarm/security companies and transaction processing companies.

EN BANC
An informal meeting held by the Commission to hear presentations on specific topics by diverse parties. The Commissioners, or other officials, question presenters and use their comments in considering FCC rules and policies on the subject matter under consideration.

FREQUENCY MODULATION (FM)
A signaling method that varies the carrier frequency in proportion to the amplitude of the modulating signal.

GLOBAL POSITIONING SYSTEM (GPS)
A US satellite system that lets those on the ground, on the water or in the air determine their position with extreme accuracy using GPS receivers.

HIGH DEFINITION TELEVISION (HDTV)
An improved television system which provides approximately twice the vertical and horizontal resolution of existing television standards. It also provides audio quality approaching that of compact discs.

HUNTING
(1) Automatic routing of calls to an idle circuit in a prearranged group when the circuit called is busy. (2) The movement of a call as it progresses through a group of lines. [Typically, the call will try to be connected on the first line of the group; if that line is busy it will try the second line and then the third, etc.]

INTERACTIVE VIDEO DATA SERVICE (IVDS)
A communication system, operating over a short distance, that allows nearly instantaneous two-way responses by using a hand-held device at a fixed location. Viewer participation in game shows, distance learning and e-mail on computer networks are examples.

INSTRUCTIONAL TELEVISION FIXED SERVICE (ITFS)
A service provided by one or more fixed microwave stations operated by an educational organization and used to transmit instructional information to fixed locations.

JACK
A connecting device having springs which make electrical contact with mating contacts of a plug.

KEY SYSTEM
A telecommunications system with multi-button telephone sets on which more than one outside line terminates, allowing several people to answer or use more than one line. [All hardware is typically located on subscriber premises.

LANDLINE
Traditional wired phone service.

LAND MOBILE SERVICE
A public or private radio service providing two-way communication, paging and radio signaling on land.

LEAST COST ROUTING (LCR)
Method for automatic selection of the least costly facility for transmission of a call. Synonyms: Most Economical Route Selection (MERS); Route Optimization; Automatic Route Selection; Flexible Route Selection.

LOW POWER FM RADIO (LPFM)
A broadcast service that permits the licensing of 50-100 watt FM radio stations within a service radius of up to 3.5 miles and 1-10 watt FM radio stations within a service radius of 1 to 2 miles.

LOW POWER TELEVISION (LPTV)
A broadcast service that permits program origination, subscription service or both via low powered television translators. LPTV service includes the existing translator service and operates on a secondary basis to regular television stations. Transmitter output is limited to 1,000 watts for normal VHF stations and 100 watts when a VHF operation is on an allocated channel.

MUST-CARRY (Retransmission)
A 1992 Cable Act term requiring a cable system to carry signals of both commercial and noncommercial television broadcast stations that are "local" to the area served by the cable system.

NETWORK
Any connection of two or more computers that enables them to communicate. Networks may include transmission devices, servers, cables, routers and satellites. The phone network is the total infrastructure for transmitting phone messages.

NUMBER PORTABILITY
A term used to describe the capability of individuals, businesses and organizations to retain their existing telephone number(s) –– and the same quality of service –– when switching to a new local service provider.

OFF-HOOK
(1) Condition existing when the receiver or handset is removed from its switchhook. (2) The active state (closed loop) of a single telephone or PBX line loop.

ON HOOK
(1) Condition existing when the receiver or handset is resting on the switchhook. (2) The idle state (open loop) of a single telephone or PBX line loop.

OPEN VIDEO SYSTEMS
An alternative method to provide cable-like video service to subscribers.

OPERATOR SERVICE PROVIDER (OSP)
A common carrier that provides services from public phones, including payphones and those in hotels/motels.

PAGING SYSTEM
A one-way mobile radio service where a user carries a small, lightweight miniature radio receiver capable of responding to coded signals. These devices, called "pagers," emit an audible signal, vibrate or do both when activated by an incoming message.

PERSONAL COMMUNICATIONS SERVICE (PCS)
Any of several types of wireless, voice and/or data communications systems, typically incorporating digital technology. PCS licenses are most often used to provide services similar to advanced cellular mobile or paging services. However, PCS can also be used to provide other wireless communications services, including services that allow people to place and receive communications while away from their home or office, as well as wireless communications to homes, office buildings and other fixed locations.

POINT-TO-POINT CIRCUIT
A private communications link between two terminations which does not connect with a public telephone system.

PRESCRIBED INTEREXCHANGE CHARGE (PICC)
The charge the local exchange company assesses the long distance company when a consumer picks it as his or her long distance carrier.

PRIVATE BRANCH EXCHANGE (PBX)
Small, local, telephone office - either manually or automatically operated - serving extensions in a business complex and providing access to the public domain.

ROAMING
The use of a wireless phone outside of the "home" service area defined by a service provider. Higher per-minute rates are usually charged for calls made or received while roaming. Long distance rates and a daily access fee may also apply .

SATELLITE
A radio relay station that orbits the earth. A complete satellite communications system also includes earth stations that communicate with each other via the satellite. The satellite receives a signal transmitted by an originating earth station and retransmits that signal to the destination earth station(s). Satellites are used to transmit telephone, television and data signals originated by common carriers, broadcasters and distributors of cable TV program material.

SATELLITE HOME VIEWER IMPROVEMENT ACT OF 1999 (SHVIA)
An Act modifying the Satellite Home Viewer Act of 1988, SHVIA permits satellite companies to provide local broadcast TV signals to all subscribers who reside in the local TV station’s market. SHVIA also permits satellite companies to provide "distant" network broadcast stations to eligible satellite subscribers.

SATELLITE MASTER ANTENNA TELEVISION (SMATV)
A satellite dish system used to deliver signals to multiple dwelling units (e.g., apartment buildings andtrailer parks).

SCANNER
A radio receiver that moves across a wide range of radio frequencies and allows audiences to listen to any of the frequencies.

SERVICE PLAN
The rate plan you select when choosing a wireless phone service. A service plan typically consists of a monthly base rate for access to the system and a fixed amount of minutes per month.

SERVICE PROVIDER
A telecommunications provider that owns circuit switching equipment.

SLAMMING
The term used to describe what occurs when a customer’s long distance service is switched from one long distance company to another without the customer’s permission. Such unauthorized switching violates FCC rules.

SPECTRUM
The range of electromagnetic radio frequencies used in the transmission of sound, data and television.

STATION MESSAGE DETAIL RECORDING (SMDR)
A computer generated report showing internal usage on a telephone system; usually includes extension number, trunk number used, phone number dialed, time of call, duration and operator involvement.

SUBSCRIBER LINE CHARGE (SLC)
A monthly fee paid by telephone subscribers that is used to compensate the local telephone company for part of the cost of installation and maintenance of the telephone wire, poles and other facilities that link your home to the telephone network. These wires, poles and other facilities are referred to as the "local loop." The SLC is one component of access charges.

T1
(1) A 1.544 circuit with the equivalent of 24 analogs. (2) The basic 24-channel 1.544 Mbps pulse code modulation system used in the United States.

TARIFF
The documents filed by a carrier describing their services and the payments to be charged for such services.

TELCO
Local telephone company; local exchange carrier.

TELECOMMUNICATIONS RELAY SERVICE (TRS)
A free service that enables persons with TTYs, individuals who use sign language and people who have speech disabilities to use telephone services by having a third party transmit and translate the call.

TELEPHONY
The word used to describe the science of transmitting voice over a telecommunications network.

TOLL RESTRICTION
Arrangement by which some telephone lines are denied access to long distance circuits.

TTY
A type of machine that allows people with hearing or speech disabilities to communicate over the phone using a keyboard and a viewing screen. It is sometimes called a TDD.

UNBUNDLING
The term used to describe the access provided by local exchange carriers so that other service providers can buy or lease portions of its network elements, such as interconnection loops, to serve subscribers.

UNIVERSAL SERVICE
The financial mechanism which helps compensate telephone companies or other communications entities for providing access to telecommunications services at reasonable and affordable rates throughout the country, including rural, insular and high costs areas, and to public institutions. Companies, not consumers, are required by law to contribute to this fund. The law does not prohibit companies from passing this charge on to customers.

VERY HIGH FREQUENCY (VHF)
The part of the radio spectrum from 30 to 300 megahertz, which includes TV Channels 2-13, the FM broadcast band and some marine, aviation and land mobile services.

VIDEO DESCRIPTION
An audio narration for television viewers who are blind or visually disabled, which consists of verbal descriptions of key visual elements in a television program, such as settings and actions not reflected in dialog. Narrations are inserted into the program’s natural pauses, and are typically provided through the Secondary Audio Programming channel.

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