telecommunication, telephony (pronEng|təˈlɛfəni "or" teh-LEH-fuh-nee) encompasses the general use of equipment to provide voice communication over distances, specifically by connecting telephones to each other.
Telephones originally were connected directly together in pairs. Each user had separate telephones wired to the various places he might wish to reach. This became inconvenient when people wanted to talk to many other telephones, so the
telephone exchangewas invented. Each telephone could then be connected to other local ones, thus inventing the local loopand the telephone call. Soon, nearby exchanges were connected by trunk lines, and eventually distant ones were as well.
In modern times, most telephones are plugged into
telephone jacks. Each jack is connected by inside wiring to a drop wire and then to a cable with other wires. Cables usually bring a large number of wires from all over a district access networkto one wire center or telephone exchange. When the user of a telephone wants to make a telephone call, equipment at the exchange examines the dialed telephone numberand connects that telephone lineto another in the same wire center, or to a trunk to a distant exchange. Most of the exchanges in the world are connected to each other, forming the Public Switched Telephone Networkor PSTN. By the end of the 20th century almost all were Stored Program Control exchanges.
After the middle 20th century fax and data became important secondary users of the network created to carry voices, and late in the century parts of the network were upgraded with
ISDNand DSLto improve handling of such traffic. Digital telephonyis the use of digital technology in the provision of telephone services and systems. Almost all telephone calls are provided this way, but sometimes the term is restricted to cases in which the last mileis digital, or where the conversion between digital and analog signals takes place inside the telephone. Telephony was digitized to cut the cost and improve the quality of voice services, but digital telephony was then found useful for new network services ( ISDN) to transfer data speedily over telephone lines. IP Telephonyis a modern form of telephony which uses the TCP/IPprotocol popularized by the internetto transmit digitized voice data. Contrast this with the operation of POTS (an acronym for " Plain Old Telephone Service").
Computer Telephony Integration (CTI) enables computers to know about and control phone functions such as making and receiving voice, fax, and data calls with telephone directory services and caller identification. The integration of telephone software and computer systems is a major development in the evolution of the automated office.
CTI is not a new concept. Such links have been used in the past in large telephone networks but only dedicated call centers could justify the costs of the required equipment installation. Primary telephone service providers are offering information services such as
Automatic Number Identificationand Dialed Number Identification Serviceon a scale wide enough for its implementation to bring real value to business or residential telephone usage. A new generation of applications (middleware) is being developed as a result of standardization and availability of low cost computer telephony links.
Wikimedia Foundation. 2010.
Look at other dictionaries:
telephony — te‧leph‧o‧ny [tˈlefəni] noun [uncountable] the activity and business of providing telephone services: • Now, devices for telephony, entertainment, and data all interact. * * * telephony UK US /təˈlefəni/ noun [U] ► COMMUNICATIONS the activity or … Financial and business terms
Telephony — Te*leph o*ny, n. The art or process of reproducing sounds at a distance, as with the telephone. [1913 Webster] … The Collaborative International Dictionary of English
telephony — 1835, a system of signaling by musical sounds; from 1876 as the art of working a telephone; see TELE (Cf. tele ) + PHONE (Cf. phone) … Etymology dictionary
telephony — ► NOUN ▪ the working or use of telephones … English terms dictionary
telephony — [tə lef′ə nē] n. 1. the science of telephonic transmission 2. the making or operation of telephones … English World dictionary
telephony — te|leph|o|ny [ tə lefəni ] noun uncount the system, technology, or business of telephone communication: video/internet/wireless telephony telephony systems … Usage of the words and phrases in modern English
telephony — [[t]tɪle̱fəni[/t]] N UNCOUNT Telephony is a system of sending voice signals using electronic equipment. These optical fibres may be used for new sorts of telephony … English dictionary
telephony — noun Telephony is used after these nouns: ↑Internet … Collocations dictionary
telephony — telefonija statusas T sritis automatika atitikmenys: angl. telephony vok. Fernsprechen, n; Telefonie, f rus. телефония, f pranc. téléphonie, f … Automatikos terminų žodynas
telephony — noun Date: 1835 the use or operation of an apparatus (as a telephone) for transmission of sounds as electrical signals between widely removed points … New Collegiate Dictionary