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Telecommunications Glossary

Learn more about telecommunications services and how they affect consumers and businesses by understanding these key terms.



Access Electronic connection to a telecommunications network. The ability of a user to enter the network. 

Access Charge Cost associated with connecting to a network. Local Exchange Carriers (LECs) collect access charges from both customers and long distance companies.

Long distance companies pay local phone companies access charges to use their network for originating and terminating long distance calls. The charges are based on minutes of use. The fees are commonly passed through to customers. Since 1985, the PUC has approved intrastate access pricing on an individual company basis.

Access Line The circuit that connects the calling party’s location with a switching center.

Area Code A three-digit code to signal the electronic equipment that the call is long distance or local call.

Area Code Relief There are two kinds of area code relief. These are Geographic Splits and Overlays. A Geographic Split divides one area code into two or more area codes. An Overlay creates a new are code to lay over the existing area codes.

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Base Rate The non-discounted "per minute" charge for Measured Service.

Basic Service Telecommunication service within a customer’s local calling area. Basic service includes the customer’s local calling plan, dial tone line, touch tone, and directory assistance calls allowed without an additional charge. Charges for basic service also include the Public Safety Emergency Telephone Act (911) fee, the Pennsylvania Relay surcharge, the Federal Universal Service Fund surcharge, the Local Number Portability surcharge and federal and state taxes, and a fee for having a non-published listing, if you choose to have a non-published number.

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Call A completed switched communication between two stations on a network. A "calling party", "calling station" or "caller" originates a call. The destination or termination of a call is the "called party," "called station(s)", or destination node on the network.

Call Duration The period of time that begins with destination off hook and ends when the call is terminated.

Central Office A telephone company facility where customer’s lines are joined to equipment that connects a customer to other customers in that central office or other central offices within the state, nation, and world. Under the current practice, this refers to the three-digit identification number under which up to 10,000 station numbers are subgrouped.

Chapter 30 The chapter from the Public Utility Code (Title 66) dealing with Alternative Form of Regulation of Telecommunications Services.

CLEC Competitive Local Exchange Carrier are companies competing for local telephone business. A new entrant into a market where there is already an incumbent Local Exchange Carrier (LEC) providing local phone service.

Collocation A competing local phone company can locate its equipment within a local exchange company’s (LEC) central office.

Common Carrier Term used to describe a telephone company.

Conservation Consideration given to the efficient and effective use of a finite numbering resource in order to minimize the cost and need to expand its availability in the introduction of new services, capabilities and features.

Contamination Occurs when at least one telephone number within thousands-block of telephone numbers is not available for assignment to end users or customers.

Contaminated Number An unavailable number within a 1K Block, at the time the 1K Block is donated to the Pooling Administrator.

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.

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Density Cell A geographic area that is characterized by the number of telephone lines per square mile. In general it is less costly to provide local loops in areas of higher line density.

Deregulation Removal or relaxation of regulations or controls governing a business or service operation such as utilities.

Dial Around Long distance services that requre consumers to dial a long-distance provider's access code (or "10-10" number) before dialing a long-distance number to bypass the consumer's chosen long-distance carrier in order to get a better rate.

Donation The term "donation" refers to the process by which carriers are required to contribute telephone numbers to a thousands-block Number Pool.

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End-User A user of telecommunication services.

Extended Loops (EELs) (Also called enhanced extended loops.) Loops that extend from the end-user directly to a CLEC’s switch.

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FCC  The Federal Communications Commission has the authority to regulate all interstate communications originating in the United States. The FCC is run by a five member board appointed by the President. 

Formal Complaint A written dispute or disagreement about a utility problem filed by a consumer with the Public Utility Commission. A formal complaint is assigned to an Administrative Law Judge (ALJ) who holds hearings to develop a record. After the hearings, the judge issues a decision. (See informal complaint.)

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Geographic Split  Divides one Area Code into any number of new area codes.

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ILEC Incumbent Local Exchange Carrier is your present local phone company, like Bell Atlantic, Sprint/United, or GTE.

Informal Complaint A dispute or disagreement about a utility problem filed by a consumer with the Public Utility Commission’s Bureau of Consumer Services (BCS). A BCS investigator reviews the informal complaint and provides the customer with a response to their dispute. Most responses are in the form of a decision that the customer or company can appeal. If an informal complaint is appealed, it becomes a formal complaint. (See Formal Complaint.)

IntraLATA Telecommunications services that originate and end in the same Local Access and Transport Area. Some "local" phone companies’ LATAs are very large and provide the equivalent of long distance service.

InterLATA Telecommunications services that originate in one and terminate in another Local Access and Transport Area (LATA).

IXC Interexchange Carrier. A telephone company that is allowed to provide long-distance telephone service between LATAs or across state lines.

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Jeopardy A jeopardy condition exists when the forecasted and/or actual demand for NXX code resources will exceed the known supply during the planning and implementation interval for relief.

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Landline Traditional wired phone service.

LATA Local Access and Transport Area.

LEC Local Exchange Carrier - the local or regional telephone company that owns and operates lines to customer locations and Class 5 Central Office Switches.

Lifeline Service A minimal telephone service designed for the poor and elderly to assure they can be reached by phone and have a "lifeline" to the world in case of emergency. The basic rate of this limited service is less than standard rates.

LNP Local Number Portability - the ability to port telephone numbers without changing telephone numbers.

LNP Port The process of moving a telephone number from one service provider to another service provider using LRN-LNP technology.

LRN  Location Routing Number - a 10-digit number, in the format NPA-NXX-XXXX. The first 6 digits of the LRN identify the switch.

Local Loop The physical wires that run from the subscriber’s telephone set, or PBX or key telephone system, to the telephone company’s central office or switch.

LSP Local Service Provider - a company that provides basic local telephone service.

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MSA Metropolitan Statistical Area refers to the geographic areas designated by the Bureau of Census that are widely recognized as indications of metropolitan character.

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NANC North American Numbering Council - the FCC advisory board that is tasked to advise on all issues relevant to the North American Numbering Plan (NANP). The council includes members from every sector of the telecom industry as well as members representing NANP member countries, states and consumers.

NANP The North American Numbering Plan - a numbering architecture in which every station in the NANP Area is identified by a unique ten-digit address consisting of a three-digit NPA code, a three digit central office code of the form NXX, and a four-digit line number of the form XXXX.

NANPA The North American Numbering Plan Administrator assigns NXX codes in each area code on a first come first served basis.

NANP Area Consists of the United States, Canada and the Caribbean countries.

NPA Numbering plan area or area code.

Non-Basic Service Non-basic services are “optional” services and include such features as Call Waiting, Caller ID, Call Forwarding, Maintenance Agreements for Inside Wiring, etc. Some optional features may not be available in your area, or they may not be compatible with certain telephone equipment. Optional features may be included in “Bundled” packages offered by the local service providers that provide telephone service in the area where you live.

Number Portability 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.

Number Conservation Measures The FCC established a process for reclaiming NXX codes from carriers who have failed to activate them with in 6 months of their availability for assignment to customers.

Number Steering Committee Pennsylvania's PUC will establish a committee to monitor the progress of the pool and to resolve issues that may arise during implementation of the pooling. 

NXX In a seven-digit local phone number, the first three digits identify the specific telephone company central office, which serves that number. These digits are referred to as the NXX where N can be any number from 2 to 9 and X can be any number.

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OCN Operating Company Number - the OCN is a numeric field identifying the Local Service Provider (LSP) that has been assigned the NXX.

Operator Service Provider (OSP) A common carrier that provides services from public phones, including payphones and those in hotels/motels.

OSS Operations Support System refers to software that processes telecommunications information and supports and manages fundamental day-to-day operations of a telecommunications provider. Customer billing and order processing, service activation, data collection and network fault monitoring are all examples of functions implemented via an OSS. An OSS is not considered a network element or part of the network (switches, fiber optics) itself.

The federal Telecommunications Act of 1996 requires Bell to provide access to its OSS, to provide the documentation and support necessary for CLECs to access and use the system, and to demonstrate that its systems are operationally ready and provide an appropriate level of performance for CLECs to enlist customers and complete all functions for its customers.

Overlay A form of area code relief. An overlay creates a new area code to lay over the existing area codes. An overlay can be an expanded overlay or a separate overlay in form.

Overlay, Expanded  An expanded overlay creates one area code covering all the older area codes.

Overlay, Separate A separate overlay puts one area code in area and one area code in another.

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Pooling Administrator (PA) The FCC will select a national Pooling Administrator who will administer the pooling of area codes nationally.

Ported Number A directory number in a Portable NPA-NXX that resides on a switch other than the switch to which it is assigned.

Price Change Opportunity (PCO) The revenue created by changes in the factors and assumptions used to determine Bell Atlantic’s rates for local service.

Public Input Hearings Meetings where consumers can give input to the PUC. Sworn or unsworn testimony to the PUC judge and to the utility, consumer advocate and PUC staff. The PUC conducts hearings in the service area of the utility that requested the rate increase. Sometimes consumers can point out problems with the quality of the utility’s service, management, or policies which could affect the outcome of a case.

Public Utility Code The law which sets the powers and duties of the PA Public Utility Commission. It also sets many of the guidelines the PUC uses for utilities' rates and service standards.

Public Utility Commission (PUC) The state regulatory agency that provides oversight, policy guidance and direction to electric, natural gas, telecommunications, water, sewer, and motor carrier vehicles public utilities.

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Rate Area A rate area denotes a geographic area used to distinguish rate boundaries.

Rate Center (RC) Uniquely defined point from which mileage measurements are determined to rate message telephone service through the application of interstate and intrastate tariffs.

Reciprocal Compensation Telephone companies pay each other to terminate local telephone calls.

Regulation A rule or law established by the federal or state government which sets procedures that a utility must follow.

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Service Portability Allows an end-user to retain the same directory number when changing services.

Service Provider Refers to a telecommunications carrier, other entity that receives numbering resources from NANPA, a pooling administrator or a telecommunications carrier for the purpose of providing or establishing telecommunications service.

Service Provider Portability Allows end-user to retain the same directory number when changing service providers.

Switch  A device that routes a call by selecting the paths or circuits to be used for transmission of information and establishing a connection.

Switching  Process of routing communications traffic from a sender to the correct receiver.

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

Telecommunications Act of 1996 (TA-96) Federal legislation enacted in 1996 to promote competition and reduce regulation in order to secure lower priced and higher quality services for American telecommunications consumers and encourage the rapid deployment of new telecommunications technologies. The Act gave various powers to FCC and states to accomplish these goals.

Terms of Service Content of the agreement between a customer and a supplier.

Title 52 The section of the Pennsylvania Code that governs utilities.

Toll Service Telecommunications service beyond a customer’s local calling area. There are two distinct types of toll service: (1) Local or Regional Toll Service which covers short distance calls made to locations outside your local calling area but within the region where you live; and (2) Long Distance Toll Service which handles calls made to locations beyond the region where you live. Toll service charges on your bill might also include any charges for any collect calls you accepted during the recent billing period.

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Unbundling The access provided by local exchange carriers (LECs) so that other service providers can buy or lease portions of its network elements, such as interconnection loops, to subscribers.

Unbundled Network Elements (UNE) The term 'network element' means a facility or equipment used in the provision of a telecommunications service. Such term also includes features, functions, and capabilities that are provided by means of such facility or equipment, including 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. Unbundling means that CLECs may lease individual parts of the network.

Unbundled Network Element Platform (UNE-P) A combination of elements including the local loop and switching.

Universal Service Service provided to every household with at least one access line for basic telephone services. 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. 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.

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Vacant Number A non-working number.

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