Telephone

Article

A telephone enables people to communicate by transmitting speech and other audio over distance. It converts sound into an electrical or radio signal, carries that signal through a network, and converts it back into sound at the receiving end.

Early telephones used analogue electrical currents over pairs of copper wires and manual switchboards. Automatic exchanges, long-distance cables, radio links, digital switching, fibre optics, satellites, and cellular networks greatly expanded their range and capacity.

Modern fixed and mobile telephones usually encode speech digitally. Calls may travel through circuit-switched networks, internet protocols, or combinations of several network technologies.

Telephone systems support voice calls, emergency access, voicemail, conferencing, messaging, data services, and video communication. Their development transformed personal communication, business, public administration, and social life while requiring large-scale standards, numbering plans, infrastructure, and regulation.

Source details and credits

• Source / publisher: Wikipedia
• URL type: WWW
• Credits: Wikipedia
• URL: https://en.wikipedia.org/wiki/Telephone