A line card or digital line card is a modular electronic circuit designed to fit on a separate

printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich str ...

(PCB) and interface with a

telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than tha ...

access network An access network is a type of telecommunications network which connects subscribers to their immediate service provider. It is contrasted with the core network, which connects local providers to one another. The access network may be furth ...

. A line card typically interfaces the

twisted pair Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted ba ...

cable of a

plain old telephone service Plain old telephone service (POTS), or plain ordinary telephone system, is a retronym for voice-grade telephone service employing analog signal transmission over copper loops. POTS was the standard service offering from telephone companies from ...

(POTS)

local loop In telephony, the local loop (also referred to as the local tail, subscriber line, or in the aggregate as the last mile) is the physical link or circuit that connects from the demarcation point of the customer premises to the edge of the comm ...

to the

public switched telephone network The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telep ...

(PSTN).

Telephone line A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or oth ...

cards perform multiple tasks, such as analog-to-digital and digital-to-analog conversion of voice,

off-hook In telephony, on-hook and off-hook are two states of a communication circuit. On subscriber telephones the states are produced by placing the handset onto or off the hookswitch. Placing the circuit into the off-hook state is also called ''seizing th ...

detection, ring supervision, line integrity tests, and other

BORSCHT Borscht () is a sour soup common in Eastern Europe and Northern Asia. In English, the word "borscht" is most often associated with the soup's variant of Ukrainian origin, made with red beetroots as one of the main ingredients, which g ...

functions. In some

telephone exchange telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital syste ...

designs, the line cards generate

ringing Ringing may mean: Vibrations * Ringing (signal), unwanted oscillation of a signal, leading to ringing artifacts * Vibration of a harmonic oscillator ** Bell ringing * Ringing (telephony), the sound of a telephone bell * Ringing (medicine), a rin ...

current and decode

DTMF Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed ...

signals. The line card in a subscriber loop carrier is called a subscriber line interface card (SLIC). A line card can terminate a line supporting voice

POTS Pot may refer to: Containers * Flowerpot, a container in which plants are cultivated * Pottery, ceramic ware made by potters * A type of cookware Places * Ken Jones Aerodrome, IATA airport code POT * Palestinian Occupied Territories, the We ...

service,

ISDN Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Wor ...

service, DSL service, or proprietary ones. Some line cards are capable of terminating more than one type of service. Since an access

network element In computer networks, a network element is a manageable logical entity uniting one or more physical devices. This allows distributed devices to be managed in a unified way using one management system. According to the Telecommunications Act of ...

is usually intended to interface many users (typically a few thousand), some exchanges have multiple line terminations per card. Likewise, one

can have many line cards.

References

{{DEFAULTSORT:Line Card Telecommunications equipment

See also

References