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Information about Telephone Line

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For the Electric Light Orchestra song, see .
A telephone line or telephone circuit (or just line or circuit within the industry) is a single-user circuit on a telephone communications system. Typically this refers to the physical wire or other signaling medium connecting the user's telephone apparatus to the telecommunications network, and usually also implies a single telephone number for billing purposes reserved for that user.

In 1876 the earliest lines were single electrically conducting metal wires directly connecting one telephone to another with the Earth forming the return circuit. Later in 1878 the Bell Telephone Company ran lines (called the local loop) from each user's telephone to end offices which performed any necessary electrical switching to allow voice signals to be transmitted to more distant telephones.

These wires were typically copper, although aluminium has also been used, and were carried in pairs separated by about 25cm (10") on poles above the ground, and later as twisted pair cables. Modern lines may run underground to a device that converts the analogue signal to digital for transmission on optical fiber.

In most cases, two copper wires for each telephone line run from a home or other small building to a local telephone exchange. There is a central junction box for the building where the wires that go to telephone jacks throughout the building and wires that go to the exchange meet and can be connected in different configurations depending upon the subscribed telephone service. The wires between the junction box and the exchange are known as the local loop.

Most houses in the U.S. are wired with 6 position modular jacks with four conductors wired to the house's junction box with copper wires. Those wires may be connected back to two telephone lines at the local telephone exchange, thus making those jacks RJ14 jacks. More often, only two of the wires are connected to the exchange, as one telephone line, and the other two are unconnected in the junction box. In that case, the jacks in the house are RJ11. In some cases, two of the wires are connected to a telephone line and two others are connected to a power source (which is usually a transformer plugged into a wall near one of the jacks) to power dialpad illumination in some older telephone sets. That is a variation on RJ11.

Wiring information / pinouts

For information on wiring for the various telephone connectors, refer to telephone plug.

See also

Motto
"In God We Trust"   (since 1956)
"E Pluribus Unum"   ("From Many, One"; Latin, traditional)
Anthem
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Electric Light Orchestra, also known as ELO, were a rock music group from Birmingham, England that released twelve albums between 1971 and 1986, and one album in 2001. The band's direction and focus for most of its history was driven by Jeff Lynne.
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Industry (from Latin industrius, "diligent, industrious"), is the segment of economy concerned with production of goods. Industry began in its present form during the 1800s, aided by technological advances, and it has continued to develop to this day.
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A telecommunication circuit is defined as follows:
  1. The complete path between two terminals over which one-way or two-way communications may be provided. See communications protocol.
  2. An electronic path between two or more points, capable of providing a number of channels.

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The telephone is a telecommunications device which is used to transmit and receive sound (most commonly speech). Most telephones operate through transmission of electric signals over a complex telephone network which allows almost any phone user to communicate with almost anyone.
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Telecommunication is the transmission of signals over a distance for the purpose of communication. In modern times, this process typically involves the sending of electromagnetic waves by electronic transmitters, but in earlier times telecommunication may have involved the use of
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A wire is a single, usually cylindrical, elongated strand of drawn metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals . Standard sizes are determined by various wire gauges.
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Telecommunication is the transmission of signals over a distance for the purpose of communication. In modern times, this process typically involves the sending of electromagnetic waves by electronic transmitters, but in earlier times telecommunication may have involved the use of
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telephone number is a sequence of decimal digits that uniquely indicates the network termination point. The number contains the information necessary to identify the intended endpoint for the telephone call.
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Billing may mean:
  • The process of sending accounts to customers for goods or services is called billing. The document used is called an invoice. The invoice may be attached to the goods or forwarded separately.

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18th century - 19th century - 20th century
1840s  1850s  1860s  - 1870s -  1880s  1890s  1900s
1873 1874 1875 - 1876 - 1877 1878 1879

:
Subjects:     Archaeology - Architecture -
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In electrical engineering, the term ground or earth has several meanings depending on the specific application areas. Ground is the reference point in an electrical circuit from which other voltages are measured, a common return path for electrical current (
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18th century - 19th century - 20th century
1840s  1850s  1860s  - 1870s -  1880s  1890s  1900s
1875 1876 1877 - 1878 - 1879 1880 1881

:
Subjects:     Archaeology - Architecture -
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The Bell System was a trademark and service mark used by the United States telecommunications company American Telephone & Telegraph Company (AT&T) and its affiliated companies to co-brand their extensive circuit-switched telephone network and their affiliations with each other.
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In telephony, the local loop (also referred to as a subscriber line) is the physical link or circuit, that connects from the demarcation point of the customer premises to the edge of the carrier, or telecommunications service provider, network.
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worldwide view of the subject.
Please [ improve this article] or discuss the issue on the talk page.
In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls.
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2, 1
(mildly basic oxide)
Electronegativity 1.90 (Pauling scale)
Ionization energies
(more) 1st: 745.5 kJmol−1
2nd: 1957.9 kJmol−1
3rd: 3666 kJmol−1

Atomic radius 135 pm
Atomic radius (calc.
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Aluminium (IPA: /ˌæljʊˈmɪniəm/, /ˌæljəˈmɪniəm/) or aluminum (IPA: /əˈluːmɪnəm/
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utility pole, telegraph pole, telephone pole, power pole, or telegraph post is a post or pole upon which telecommunication network equipment is situated.
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Twisted pair cabling is a form of wiring in which two conductors are wound together for the purposes of canceling out electromagnetic interference (EMI) from external sources, electromagnetic radiation from the UTP cable, and crosstalk between neighboring pairs.
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analog-to-digital converter (abbreviated ADC, A/D or A to D) is an electronic integrated circuit, which converts continuous signals to discrete digital numbers. The reverse operation is performed by a digital-to-analog converter (DAC).
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An analog or analogue signal is any time continuous signal where some time varying feature of the signal is a representation of some other time varying quantity. It differs from a digital signal in that small fluctuations in the signal are meaningful.
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In telecommunications, transmission is the forwarding of signal traffic over distances that are too great to be simply connected by a twisted pair wires. Techniques available now may be microwave link, satellite link, coaxial cable or fibre optic cable.
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An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length. Fiber optics is the overlap of applied science and engineering concerned with such optical fibers.
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worldwide view of the subject.
Please [ improve this article] or discuss the issue on the talk page.
In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls.
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In telephony, the local loop (also referred to as a subscriber line) is the physical link or circuit, that connects from the demarcation point of the customer premises to the edge of the carrier, or telecommunications service provider, network.
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Modular connector is the name given to a family of electrical connectors examples of which are pictured. These connectors were originally used in telephone wiring. Even though they are still used for that purpose they are used for a variety of other things as well.
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In science and engineering, conductors, such as copper or aluminum, are materials with atoms have loosely held valence electrons. See electrical conduction.

Conductors in context


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worldwide view of the subject.
Please [ improve this article] or discuss the issue on the talk page.
In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls.
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RJ11 is a physical interface often used for terminating telephone wires. It is probably the most familiar of the registered jacks, being used for single line POTS telephone jacks in most homes and offices in North America and many other countries.
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