Analog: A continuous electrical signal that carries information by means of variations in its amplitude of frequency. Telecommunications signals are sent in either analog or digital format.

CAC: Carrier Access Code. A code dialed by a subscriber before a long distance call to access a particular long distance carrier's facilities. (101_ _ _ _).

CIC: Carrier Identification Code. A three or four-digit code assigned by Bellcore which identifies a long distance carrier.

Circuit: A communication path between two or more points.

CLASS: Custom Local Area Signaling Services. Enhanced telephone features, such as Caller Identification and Last Call Return, which are made possible through software upgrades and SS-7 networks.

CO: Central Office. A local telephone company office within a telephone exchange where customers' lines are terminated for purposes of interconnection to each other and to trunks.

CPE: Customer Provided Equipment. Telephone equipment that is owned by the end user customer, not the telephone company.

Cramming: Unauthorized or fraudulent charges billed by a third party on a subscriber's local telephone bill.

Custom Calling: Telephone features, including Call Waiting and Three-Way Calling made available through digital switching equipment and software.

Digital: A discontinuous electrical signal that carries information by means of variations in its duration or amplitude.

Drop: Telephone wire from a pole or duct to the subscriber's residence or business.

E911: Enhanced 911. Emergency telephone service which transmits the calling telephone number and location to the dispatch center.

EAS: Extended Area Service. Allows subscribers of separate telephone exchanges to call back and forth between exchanges without incurring long distance charges.

E-Mail: Electronic Mail. Messages sent and stored electronically, usually with a personal computer and modem.

E-Rate: Federally funded discounts provided to schools, libraries and health care facilities for telecommunications products and services. Established by the Telecommunications Act of 1996 to ensure that eligible facilities have affordable access to the global communications network.

Exchange: A geographical area established for the provision of local telephone service. The exchange is identified by the three digits following the area code in the telephone number. (note: CMC serves 13 exchanges, Triangle Telephone Cooperative serves 26).

FCC: Federal Communications Commission. The federal agency, established under the Communications Act of 1934, which regulates interstate telecommunications.

HSO: Host Switching Office. An electronic switching machine that provides the centralized control over most of the telephone switching functions of a group of remote switches. (TTC/CMC has two HSO's, one in Havre and one in Big Timber).

ISP: Internet Service Provider. An organization (such as TTC/CMC) which provides the modems and lines necessary to connect subscribers with a computer and modem to national Internet points of presence.

ITV: Interactive Television. A telecommunications service which allows users in separate locations to see and hear one another on television sets and other more specialized equipment. (Many Montana schools have ITV service for sharing classes with other schools and colleges. The service is offered through TTC and CMC's ownership in the VisionNet consortium of telephone cooperatives).

IXC: Interexchange Carrier. A company which provides long distance service to telephone subscribers.

LATA: Local Access Transport Area. Geographic areas established with the Bell System divestiture of 1984. Montana is broken into two large and one small LATA. The LATA boundaries determined which type of company carries a long distance call (either a local exchange carrier or an interexchange carrier). The advent of IntraLATA equal access has made the concept of LATA's less important, as IXC's can now provide service for all types of long distance calls if they choose.

LEC: Local Exchange Carrier. A company which provides local telephone service by connecting subscribers to the national telephone network. (CMC and Triangle Telephone Cooperative are examples of LEC's).

NID: Network Interface Device. The physical point (often located in a plastic box) at a subscriber's home or business where the inside telephone wiring is connected to the telephone company's transmission lines.

PCS: Personal Communications Service. A completely digital enhanced wireless telecommunications service. PCS offers several advantages over regular cellular service.

PIC: Primary Interexchange Carrier. The long distance company a subscriber has chosen to provide their toll service. The local telephone company programs the subscriber's PIC into the switch so that long distance calls will automatically go to that carrier, unless a special dialing pattern is used.

PIC Freeze: Primary Interexchange Carrier Freeze (Also called a PIC Change Refusal): A service offered by TTC and CMC to help subscribers prevent being slammed by long distance carriers. When a PIC Freeze is in place, we will not change a subscriber's PIC without the account holder's identity verification and authorization.

PIN: Personal Identification Number. A specified number of digits used by an individual to access certain services, such as Voice Mail, Automated Teller Machines, Voice Response Systems, etc. Establishing a PIN prevents unauthorized use.

POTS: Plain Old Telephone Service. Basic telephone service for the transmission of human speech.

PSC: Public Service Commission. The state of Montana's organization which regulates intrastate telecommunications.

RBOC: Regional Bell Operating Company. The seven local exchange carriers created by the AT & T divestiture in 1984. U.S. West Communications is one of the RBOC's.

Slamming: The unauthorized changing of a subscriber's long distance carrier.

SLC: Schools and Libraries Corporation. The federal organization which oversees the Universal Service Fund for Schools and Libraries Program, (also known as E-Rate) which was established with the Telecommunications Act of 1996.

SS-7: Signaling System 7. A standardized system of telecommunications hardware and software which enhance telephone service. Once all the hardware and software is installed and interconnected with the necessary entities, subscribers are able to use Caller Identification and other CLASS features.

Switch: A telephone company's computerized device which opens or closes circuits, changes operating parameters or select paths or circuits.

Trunk: A communications path in a telephone network connecting two switching systems used in the establishment of an end-to-end connection. For example: numerous trunks are used to connect TTC and CMC's switching offices to all the long distance carriers who choose to provide service to our subscribers.

UA: Universal Access. The goal of regulators to make telephone service available to the greatest number of people on an equitable basis at reasonable charges.