Search results
Results from the WOW.Com Content Network
A sound-powered telephone is a telephone which transmits voice communication by wire, powered by the energy of the sound waves of the operator speaking. Principle of operation A moving-coil microphone converts the sound waves into an electrical signal, which is then converted back into sound waves at the receiver's end.
The first and historically most important application for communication satellites was in intercontinental long-distance telephony. The fixed Public Switched Telephone Network relays telephone calls from land line telephones to an earth station , where they are then transmitted a receiving satellite dish via a geostationary satellite in Earth ...
In practice, most intercontinental communication will use the Asynchronous Transfer Mode (ATM) protocol (or a modern equivalent) on top of optic fibre. This is because for most intercontinental communication the Internet shares the same infrastructure as the public switched telephone network.
A commercial IP telephone, with keypad, control keys, and screen functions to perform configuration and user features. The field of technology available for telephony has broadened with the advent of new communication technologies. Telephony now includes the technologies of Internet services and mobile communication, including video conferencing.
In 1876, Alexander Graham Bell invented the telephone. After 1920 it replaced the telegraph as the primary means of communication between cities. As the telegraph was eventually supplanted, it paved the way for the development of modern communication systems and revolutionized the way people communicate over long distances. [16]
The development of new communication technologies, such as telephone, radio, newspapers, television, and the internet, has had a big impact on communication and communication studies. [232] Today, communication studies is a wide discipline. Some works in it try to provide a general characterization of communication in the widest sense.
The master telephone patent granted to Bell, 174465, March 7, 1876. The modern telephone is the result of the work of many people. [12] Alexander Graham Bell was, however, the first to patent the telephone, as an "apparatus for transmitting vocal or other sounds telegraphically".
The telephone played a major communications role in American history from the 1876 publication of its first patent by Alexander Graham Bell onward. In the 20th century the American Telephone and Telegraph Company (AT&T) dominated the telecommunication market as the at times largest company in the world, until it was broken up in 1982 and replaced by a system of competitors.