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 that fe ...

s, an interface standard is a

standard Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object th ...

that describes one or more functional characteristics (such as

code conversion In telecommunication, the term code conversion has the following meanings: 1. Conversion of signals, or groups of signals, in one code into corresponding signals, or groups of signals, in another code. 2. A process for converting a code of ...

, line assignments, or

protocol Protocol may refer to: Sociology and politics * Protocol (politics), a formal agreement between nation states * Protocol (diplomacy), the etiquette of diplomacy and affairs of state * Etiquette, a code of personal behavior Science and technolog ...

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 synchr ...

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 en ...

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 producti ...

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 ...

plus signaling paths to indicate call progress and status information, such as ringing, answer supervision, 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 e ...

* 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 e ...

* DPO

dial pulse Pulse dialing is a signaling technology in telecommunications in which a direct current local loop circuit is interrupted according to a defined coding system for each signal transmitted, usually a digit. This lends the method the often used name ...

originate * DPT

terminate *

E and M signaling E and M signaling is a type of supervisory line signaling that uses DC signals on separate leads, called the "E" lead and "M" lead, traditionally used in the telecommunications industry between telephone switches. Various mnemonic names have been us ...

* 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