Glossary of Common Telecommunications Terms
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

Access – The ability of one company to connect to or use another company's communications services or facilities. The 1996 Telecommunications Act mandates that there be no discrimination between or against service providers – that the operating environment must be "neutrally competitive."

Access Charge – The charges long distance providers pay to local telephone service providers for use of the local network to complete long distance calls.

Access Line – The circuit between a telephone subscriber and the local switching center.

Advanced Television Services – Television services provided using digital technology.

• High Definition Television (HDTV): Refers to digital systems that offer approximately twice the vertical and horizontal resolution of standard analog systems available today.
• Standard Definition Television (SDTV): Refers to digital systems with approximately equal resolution of standard analog systems available today.

Affiliate – A company that (directly or indirectly) owns or controls at least 10% of another company.

Analog – In telecommunications, the generation of a constant electrical signal that is comparable ("analogous") to the original voice, data or video input. In short, transmissions that are not digital (see below). For a comparison of analog and optic transmission capabilities, see "speed."

ARPANET – The precursor to the Internet, ARPANET was a large Wide Area Network established in 1969 by the United States Defense Advanced Research Project Agency (ARPA) linking many universities and research centers.

AT&T Consent Decree – The order entered August 24, 1982, in the antitrust action styled United States v. Western Electric resulting in AT&T's separation from its regional operating companies, known as the Baby Bells.

B

Bandwidth – The capacity of your Internet connection to transmit and receive data. Bandwidth is most accurately measured in cycles per second, or hertz (Hz), which is the difference between the lowest and highest frequencies transmitted. But it's also common to use bits or bytes per second instead.

Basic Service – The minimum set of capabilities deemed necessary for use of the public telecommunications network. Current basic service includes an access line (usually one-party, analog, rotary dial), access to local and long distance calling, access to emergency calling (911), and access to voice/nonvoice relay service.

Baud Rate – A measurement of the amount of data or symbols that can be transmitted per second. This is not always the same as the bps (bits per second) rate because a given symbol, or baud, may have more than one bit.

Broadband – The capacity of a network. Most commonly refers to the evolving generation of high-speed, digital connections being installed at customer premises by cable and phone companies to deliver voice, high-speed data, video-demand services, and interactive delivery services. It can be delivered by DSL over copper wire, by fiber optics, satellite or wireless technology.

Browser – A software program that enables users to explore the World Wide Web. Two of the most popular browser programs are Microsoft Internet Explorer and Netscape.

C

Cable Service – one-way transmission of video programming to subscribers.

Cache – When Web sites are visited they are temporarily stored in the cache folder associated with the Web browser so they can be retrieved more quickly when a Web page is revisited.

Calling Number Identification Service (CNI) – Caller ID. With a display unit attached to a telephone and subscription to this service, a caller's number is identified on incoming calls.

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.

Cell – The geographic area covered by a single base station in a cellular mobile network.

Cellular – A mobile telephone service provided by a network of base stations, each of which covers one geographic cell within the total cellular system service area.

Centrex – A customer service offered from a telecommunications company's central office that offers intercom, call forwarding, call transfer and other features. (Compare with Private Branch Exchange.)

CDMA – Code Division Multiple Access. A digital spread-spectrum wireless transmission technology that transmits data from calls across the entire frequency band with codes for proper signal recovery at the other end (see PCS).

CLEC – Competitive Local Exchange Carrier. Any company offering local telephone service, whether facilities-based or resold, in an area already served by an ILEC.

CO – Central Office. A local telephone company switching station that covers a geographic area, such as a section of a city or a town. A central location where all calls within a particular area are routed through.

Coaxial (or coax) Cable – An insulated sheath surrounding a metal core conveying information in electric current.

Collocation – A telco's ability, for example, to connect to a local or long distance telephone company by having its equipment physically located in the other company's facilities.

Common Carrier – An entity that provides a public communications conduit without regard to content.

CD-ROM – Compact Disc, Read-Only Memory. A compact disc used to store and play back computer data instead of digital audio. The hardware used to play the discs on is called a CD-ROM drive.

Copper Wire – A transmission medium where signals travel in the form of electric current.

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.

Customer Premises Equipment (CPE) – Equipment employed on the premises of a person (other than a carrier) to originate, route, or terminate telecommunications.

Cyberspace – Science fiction writer William Gibson coined the term cyberspace in his novel Neuromancer to describe a virtual world of computer networks. The word also refers to virtual reality, the Internet, the World Wide Web, and many other kinds of computer systems in which users become immersed.

D

Dark Fiber – Fiber optic cable that is not in use (i.e., carrying light). If provided or sold, the recipient/buyer is expected to install equipment to transmit information (i.e., "light") the cable.

Database – A collection of data that is organized in a way that its contents can be easily accessed, managed and updated.

Data Transmission – Computers and other devices communicating on a network. Examples include e-mail, the Internet, ATMs.

Dedicated – Allocation of a specific cable or capacity for the exclusive use of one customer.

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.

Dial-Up – The most basic way to access the Internet by connecting with a computer and a modem to an ISP (Internet Service Provider). Typically a lot slower than a high-speed connection like digital subscriber line, or DSL. Due to technology restrictions, the maximum data transfer rate that can be achieved with a dial-up modem is limited to 56 Kbps, or 56 thousand bits per second.

Digital – Information carried as a stream of binary "1s" and "0s" instead of as an analog electric signal.

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

Domain Name – The address or URL of a particular Web site. It is the text name corresponding to the numeric IP address of a computer on the Internet. Domain names are registered by accredited registrars of the Internet Corporation for Assigned Names and Numbers (ICANN). In the 1980s, seven Top Level Domains, or TLDs were created. They are: .com, .edu, .gov, .int, .mil, .net, and .org. Domain names may be registered in three of these (.com, .net, and .org) without restriction; the other four have limited purposes. Seven new TLDs were introduced in 2001 and 2002. Four of the new TLDs (.biz, .info, .name, and .pro) are unsponsored. The other three new TLDs (.aero, .coop, and .museum) are sponsored.

DSL – Digital Subscriber Line, in either ASDL (Asymmetrical) or VDSL (Very High Speed) form, sends data over copper wires much faster than normal (allowing transmission of digital TV, for example, without installing a new network of cables).

E

E911 – Enhanced 911. A location technology advanced by the FCC that will enable mobile or cellular phones to process 911 emergency calls and enable emergency services to locate the geographic position of the caller.

Encryption – The process of changing data into a form that can be read only by the intended receiver. To decipher the message, the receiver of the encrypted data must have the proper decryption key. In traditional encryption schemes, the sender and the receiver use the same key to encrypt and decrypt data.

Equal Access – All service providers must have equal access to the market. Section 253(a) of the Telecommunications Act of 1996 directs that "no State or local statute or regulations, or other State or local legal requirement, may prohibit or have the effect of prohibiting the ability of any entity to provide any interstate or intrastate telecommunications service."

ETC – Eligible Telecommunications Carrier (or, CETC for competitive eligible telecommunications carrier) is a designation given to a wireline or wireless carrier that offers telephone service to all consumers throughout a service area without preference and it advertises the available supported services in the mass media. Carriers must meet certain federal and state requirements before receiving an ETC designation and subsequent support from the universal service fund for the provision, maintenance, and upgrading of facilities and services for which the support is intended.

Exchange – A specific geographic area designated by the Minnesota Department of Commerce, which is served by one or more central offices.

Exchange Access – The offering of access to telephone exchange services or facilities for the purpose of the origination or termination of telephone toll services.

F

Facilities-Based – A telecommunications company provides its services over wire and cable that they own (opposite of resale).

FCC – The Federal Communications Commission is an independent United States government agency, directly responsible to Congress. The FCC was established by the Communications Act of 1934 and is charged with regulating interstate and international communications by radio, television, wire, satellite and cable. The FCC's jurisdiction covers the 50 states, the District of Columbia, and U.S. possessions.

Fiber Mile(s) – Route mile(s) (see below) multiplied by the number of fiber optic cables laid over that distance. Typically, 50 or more cables are contained in a single protective sheath so that such a collective "cable" over one mile would yield 50 fiber miles.

Fiber Optic Cable – Sheathed strands of very thin telecommunications cable of various diameters usually made from extremely transparent glass that is capable of transmitting great amounts of digital information on pulses of light at very high speed and with high quality.

Frames – A method of splitting an HTML page into two or more windows.

Frame Relay – A data network that sends data in "frames." Similar to "packets," only with higher capacities.

FTP – File Transfer Protocol. A method used to transfer files between computers. Useful in uploading files to company or personal Web site.

G

GSM – Global System for Mobile Communications (Groupe Speciale Mobile). This set of standards is widely used in Europe for cellular communications. The audio encoding subset of the GSM standard is best known to computer users because its data compression and decompression techniques are also being used for Web-phone communication and encoding WAV and AIFF files.

H

HDTV – High Definition Television. 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.

HTML – Hypertext Markup Language. A collection of formatting commands that create hypertext documents, or Web pages. HTML commands cover many types of text formatting (bold and italic text, lists, headline fonts in various sizes, and so on), and also have the ability to include graphics and other nontext elements. Development and maintenance of HTML standards is coordinated by the World Wide Web Consortium.

HTTP – Hypertext Transfer Protocol. The protocol used to transmit and receive all data over the World Wide Web. When you type a URL into your browser, you're actually sending an HTTP request to a Web server for a page of information. (Did you notice that URLs begin with "http://"?).

Hyperlink – A place on a Web site (text or image) that points the browser to a related screen or page.

I

ILEC – Incumbent Local Exchange Carrier. A provider of local telecommunications services.

Information Highway – The combined total of all fiber optic and electronic systems devoted to moving information in whatever form between producing and using parties. The Internet is one component.

Interconnection – Equal access to networks between incumbent and competitive local exchange carriers.

Interlata Service – Telecommunications between a point located in a local access and transport area (LATA) and a point located outside such area.

Internet – A worldwide connected set of networks, specifically those using TCP/IP, that anyone can access through a personal computer and modem. The Internet, most likely the largest Wide Area Network in the world, began in the late '60s and early '70s as ARPANET, a networking research project commissioned by the U.S. Department of Defense in the midst of the Cold War.

IP Address – A unique, numeric address for each computer connected to the Internet.

ISDN – Integrated Services Digital Networks can carry voice and data simultaneously.

IXC – Interexchange Carrier. Commonly known as long distance, carries intra– or interstate communications between local exchanges.

L

LAN – Local Area Network. Private short distance data communications network operating under central control (see WAN).

Landline – Traditional wired phone service.

LATA – Local Access and Transport Area. One of 161 contiguous geographic areas in the United States, established before the Telecommunications Act of 1996, in which a telephone company may provide local or long distance service.

LEC – Local Exchange Carrier. Any company that is engaged in the provision of telephone exchange service or exchange access (see ILEC).

Listserv – An automatic mailing list server developed in 1986. When e-mail is addressed to a listserv mailing list, it is automatically broadcast to everyone on the list. The result is similar to a newsgroup or forum, except that the messages are transmitted as e-mail and are therefore available only to individuals on the list. Although listserv refers to a specific mailing list server, the term is sometimes used incorrectly to refer to any mailing list server.

Local Loop – A generic term for the connection between the customer's location (home or office) and the provider's central office.

M

Modem – An acronym for modulator/demodulator. A device that converts digital signals to analog signals and vice versa. Modems are most often used to connect computers to telephone lines.

MTA – Minnesota Telecom Alliance. A not-for-profit professional association that represents the interests of small, medium and large telecommunication companies providing voice, data, wireless, and high-speed broadband services to Minnesota’s metropolitan and rural communities.

MTSO – A Mobile Telephone Switching Office controls cellular base stations and handles phone connections to the public switched network.

N

Network – An interconnection of three or more communicating entities.

Network Element – A facility or the equipment used in the provision of a telecommunications service. The term includes subscriber numbers, databases, signaling systems, and information sufficient for billing and collection or used in the transmission, routing, or other provision of a telecommunications service.

NID – Network Interface Device. A device that connects the local loop to the customer premises and includes the demarcation point.

Number Portability – Term used to describe the capability of a customer to retain their existing telephone number(s) – and quality of service – when switching local service providers.

O

Overhead – In telecommunications, information added at the beginning and end of customer traffic for control, routing, error-checking and other system operating and maintenance functions.

OVS – Open Video Systems. An alternative method to provide cable-like video service to subscribers.

P

Packet-Switched Networks – Digital data sent in quantities called "packets" can follow different routes and arrive out of sequence but can be reassembled in original form.

PBX – Private Branch Exchange. Sometimes called a private business exchange, a PBX is a privately owned switch that permits the kind of services associated with centrex (see above), plus the ability to tailor the switch's program to the owner's specific needs.

PCS – Personal Communications Services. A generic description of cellular communications services that combine voice, data, and paging features into a single device. The GSM and CDMA digital cellular standards can both be used for PCS.

PDF – Portable Document Format. A technology that allows documents to be viewed and printed on multiple platforms while retaining their original appearance.

POTS – Plain Old Telephone Service. This term commonly refers to standard telephony, as in placing and receiving telephone calls.

Private Network – A network of lines leased by a private customer.

Public Rights-Of-Way – Use of public resources for creation or maintenance of infrastructure.

Public Switched Network – The "landline" network all wired phones are connected to.

R

RBOC – Regional Bell Operating Company. The seven "Baby Bells" created as part of the AT&T consent decree. While RBOCs are incumbent local exchange carriers (ILECs), not all ILECs are RBOCs.

Resale – A CLEC buys services from an ILEC and resells the services over the ILEC's facilities (opposite of facilities-based).

Route Mile – The length (distance) of installed cable (see fiber miles).

S

Selective Call Rejection – Enables customers to establish a screening list that will prevent calls from terminating to the customer. Callers on the screening list are directed to an announcement informing them their call is not presently being accepted.

Self-Healing Ring – A "circular" network design that simultaneously moves traffic in two directions; therefore, if the cable is cut or there is a component failure along one of the two paths, communication continues in the other direction.

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.

Smart Building – A building with fiber optic cable and switches that permit occupants to use advanced computer systems, connect with high speed external telecommunications and employ other cutting edge telecommunications technologies. In most markets, there is more demand for space in smart buildings, which usually earns a premium compared to space in traditional facilities.

SONET – Synchronous Optical Network: Standards established by the American National Standards Institute defining optical fiber transmission speeds, manufacturing requirements, interface criteria and other requirements for compatible transmission of traffic.

Spam – Unwanted bulk e-mail solicitations, similar to junk mail.

Speed – Actually, both electronic and fiber optic systems operate at near the speed of light. "Speed" often is used to mean "capacity", how much information can be transmitted in what period of time, as in "kilobits per second." At 2.5 Gbs, (billion bits per second), the entire Encyclopaedia Britannica could be transmitted in less than .006 of a second. By comparison, it takes .1 seconds to blink an eye, and it would take nearly four minutes – 44,000 times longer – to transmit the same information over a standard analog voice telephone line. Unless applied to a dedicated line, the nature of digital transmission allows capacity to be divided between customers or between different types of traffic (i.e., voice, data or video).

SLC – Subscriber Line Charge. 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 local network. The SLC is one component of access charges.

Switch – A device that automatically selects the necessary connections to route traffic from a caller to a receiver.

T

T-1 – A high-speed line for data transmission.

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

TARP – Telecommunications Access Resource Program. Provides funds to help individual schools across Minnesota, including private and charter schools, get connected to each other and to the Internet. The funds also help pay the ongoing expenses of Internet and video hookups.

TDMA – Time Division Multiple Access. A digital cellular wireless transmission technology that divides cell channels into three time slots so more calls can be carried.

Telco – The local telephone company operator in a given area.

Telecommunications – The transmission, between or among points specified by the user, of information of the user's choosing (including voice, data, image, graphics, and video), without change in the form or content of the information.

Telecommunications Act of 1996 – According to its preamble, an Act to promote competition and reduce regulation in order to secure lower prices and higher quality services for American telecommunications consumers and encourage the rapid deployment of new telecommunications technologies.

Telecommunications Carrier – Any provider of telecommunications services.

Telecommunications Equipment – Equipment, other than customer premises equipment, used by a carrier to provide telecommunications services, and includes software integral to such equipment (including upgrades).

Telecommunications Service – The offering of telecommunications for a fee directly to the public, or to such classes of users as to be effectively available directly to the public, regardless of the facilities used.

Telephone Company Central Office – See Central Office.

Telephone Exchange Area – See Exchange.

TELRIC – Total Element Long-Run Incremental Cost. Established in 1996 by the FCC, it's the formula used by state commissions to determine the wholesale rates for network elements that are charged by ILECs. Since it is based on a forward-looking cost model - instead of how an ILEC network looks today - TELRIC has seen some legal challenges.

Toll Restriction – Allows customers to block calls to specified codes (NPA or NPA-NXXs). Toll restricted stations cannot make any toll calls.

TRS – Telecommunications Relay Service. 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.

Twisted Pair – A common form of copper cabling used for telephony and data communications.

U

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.

UNEs – Unbundled Network Elements. Individual parts of an ILEC network that are leased by competitors for the transmission, routing or other provisioning of a telecommunications service. An FCC rule determined that ILECs are required to provide these elements, at a discount, to competing telcos. UNEs may include loops, lines, switches, NIDs and other transport facilities as well as information required to efficiently bill and collect for services.

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.

URL – Universal Resource Locator. The address of a particular site on the World Wide Web.

V

V-Chip – A device which can be programmed to block programming from being viewed on a television. Since January 1, 1998, all TV sets sold in America were to include a V-Chip. A complementary ratings system of television programming debuted in January 1997.

Virus – An unwanted, disruptive, and sometimes destructive program that places itself into other programs which are shared among computer systems, and replicates itself. Some viruses are designed to automatically spread to other computer users and can be transmitted as e-mail attachments, downloads, or be present on a diskette or CD.

W

WAN – Wide Area Network. Private long distance network operating under central control (see LAN).

World Wide Web (WWW) – Also referred to as the Web, it is an international, network-based information service composed of Internet host computers, or Web servers, that present text, graphics, video and sound files together in a specific hypertext format viewed with Internet browsers. The Web is only a portion of the Internet. There are thousands of databases outside the Web that require other means to access them. It was originally developed by CERN labs in Geneva, Switzerland. Continuing development of the Web is overseen by the World Wide Web Consortium.

Sources:
Anglia Polytechnic University www.anglia.ac.uk
Benton Foundation www.benton.org
CNET www.cnet.com
Federal Communications Commission www.fcc.gov
Hoover's www.hoovers.com
International Telecommunication Union www.itu.int
Internet Corporation for Assigned Names and Numbers www.icann.org
ISP World www.ispworld.com
Lucent Technologies www.lucent.com/search/glossary
Minnesota Telecom Alliance www.mnta.org
National Center for Small Communities www.smallcommunities.org
National Data Mux www.nationaldatamux.com
NetLingo www.netlingo.com
Pennslyvania Public Utility Commission puc.paonline.com
Webopedia www.webopedia.com