telephone

Introduction & Top Questions
The telephone instrument
- Working components of the telephone
  - Power source
  - Switch hook
  - Dialer
  - Ringer
  - Transmitter
  - Receiver
  - Anti-sidetone circuit
- Development of the telephone instrument
  - Early sound transmitters
  - Gray and Bell: the transmission of speech
    - The first devices
    - The search for a successful transmitter
  - Development of the modern instrument
- Cordless telephones
- Personal communication systems
The telephone network
- Switching
  - Switching systems
    - Manual switching
    - Electromechanical switching
    - Electronic switching
    - Digital switching
  - The switching network
- Signaling
  - Call-number dialing
    - Rotary dialing
    - Push-button dialing
  - Interoffice signaling
    - In-band signaling
    - Out-of-band signaling
- Transmission
  - Development of long-distance transmission
    - From single-wire to two-wire circuits
    - Problems of interference and attenuation
    - From analog to digital transmission
    - Coaxial cable
    - Microwave link
    - Optical-fibre cable
  - Overseas transmission
    - Terrestrial radio
    - Undersea cable
    - Satellite

References & Edit History Quick Facts & Related Topics

Images, Videos & Interactives

Alexander Graham Bell sits at a desk speaking into an early telephone, surrounded by a crowd of men observing the event in a formal room.

Portrait of Alexander Graham Bell with an early telephone device positioned in front of him, symbolizing the first telephone call in history.

Alexander Graham Bell demonstrating the telephone

Evolution of the Phone: A look at telephone technology through the decades.

A man in period clothing speaks into an early telephone device in a black-and-white dramatization of Alexander Graham Bell's first successful telephone call.

telephone c. 2000

Alexander Graham Bell's 1876 sketch of an early telephone design, showing a man speaking into a large cone connected to a device, with handwritten notes below.

Engraving of Alexander Graham Bell seated at a table filing his telephone patent with an official; Bell's early telephone device rests on a separate table to the right.

Alexander Graham Bell

At a Glance

default image

telephone summary

Alexander Graham Bell sits at a desk speaking into an early telephone, surrounded by a crowd of men observing the event in a formal room. — Alexander Graham Bell and the New York City–Chicago telephone link Alexander Graham Bell, who patented the telephone in 1876, inaugurating the 1,520-km (944-mile) telephone link between New York City and Chicago on October 18, 1892.

telephone

telecommunications

Also known as: telephony

Written by

David E. Borth

Fact-checked by

Britannica Editors

telephone, an instrument designed for the simultaneous transmission and reception of the human voice. The telephone is inexpensive, is simple to operate, and offers its users an immediate, personal type of communication that cannot be obtained through any other medium. As a result, it has become the most widely used telecommunications device in the world. Billions of telephones are in use around the world. This article describes the functional components of the modern telephone and...

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