telecommunication 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 ...

s, an interface standard is a standard that describes one or more functional characteristics (such as code conversion,

line Line most often refers to: * Line (geometry), object with zero thickness and curvature that stretches to infinity * Telephone line, a single-user circuit on a telephone communication system Line, lines, The Line, or LINE may also refer to: Art ...

assignments, or protocol compliance) or physical characteristics (such as electrical, mechanical, or optical characteristics) necessary to allow the exchange of

information Information is an abstract concept that refers to that which has the power to inform. At the most fundamental level information pertains to the interpretation of that which may be sensed. Any natural process that is not completely random, ...

between two or more (usually different) systems or pieces of equipment.

Communications protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchro ...

s are an example. An

interface Interface or interfacing may refer to: Academic journals * ''Interface'' (journal), by the Electrochemical Society * '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics'' * '' Int ...

standard may include operational characteristics and acceptable levels of performance. In the military community, interface standards permit

command and control Command and control (abbr. C2) is a "set of organizational and technical attributes and processes ... hatemploys human, physical, and information resources to solve problems and accomplish missions" to achieve the goals of an organization or e ...

functions to be performed using communication and computer systems.

Telephones

There are many interface standards between analog telephone central office equipment and

customer-premises equipment In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation po ...

. Single

voice The human voice consists of sound made by a human being using the vocal tract, including talking, singing, laughing, crying, screaming, shouting, humming or yelling. The human voice frequency is specifically a part of human sound production ...

paths generally include analog audio connections, either a

two-wire circuit In telecommunication, a two-wire circuit is characterized by supporting transmission in two directions simultaneously, as opposed to four-wire circuits, which have separate pairs for transmit and receive. The subscriber local loop from the telco c ...

four-wire circuit In telecommunication, a four-wire circuit is a two-way circuit using two paths so arranged that the respective signals are transmitted in one direction only by one path and in the other direction by the other path. The four-wire circuit gets its n ...

plus signaling paths to indicate call progress and status information, such as ringing,

answer supervision In telecommunication, supervision is the monitoring of a telecommunication circuit for telephony to convey to an operator, user, or a switching system, information about the operational state of the circuit. The typical operational states of trunks ...

, etc. Some of the known interface types are: * FXO

foreign exchange office Foreign exchange service (FX) is an access service in a telecommunications network in which a telephone in a given exchange area is connected, via a private line, as opposed to a switched line, to a telephone exchange or central office in another ...

* FXS

foreign exchange station Foreign exchange service (FX) is an access service in a telecommunications network in which a telephone in a given exchange area is connected, via a private line, as opposed to a switched line, to a telephone exchange or central office in another ...

* DPO dial pulse originate * DPT dial pulse terminate * E and M signaling * KS Kewlstart *

Loop start Loop start is a telecommunications supervisory protocol between a central office or private branch exchange (PBX) and a subscriber telephone or other terminal for the purpose of starting and terminating a telephone call. It is the simplest of the ...

Ground start {{refimprove, date=January 2008 In telephony, ground start is a method of signaling from a terminal of a subscriber local loop to a telephone exchange, where one side of a cable pair is temporarily grounded to request dial tone. Most middle 20th-c ...

References

* Telecommunications standards {{telecomm-stub

Telephones

See also

References