Telephone [English: telephone, from Greek τ? λε(tēle, meaning "far") and φ ω ν? (ph n ē, meaning "sound"), the old translation is a long-distance communication device, which can transmit and receive sound. As early as the eighteenth century, the word "telephone" was used in Europe to refer to microphones strung together with wires (cups strung together with wires) The telephone was attributed to Alexander Graham Bell. The principle of early telephone is that sound is a compound vibration in the air, which can be transmitted to solids and to conductive metals through electric pulses. Bell applied for the telephone patent in March 1876.
On June 5th, 2002, the United States Congress confirmed Antonio Muzzi as the inventor of the telephone. Zi Mu first showed his invention to the public at 1860, and published an introduction in an Italian newspaper in new york.
The improvements and inventions of telephone in history include: toner microphone, manual switchboard, dial, automatic telephone exchange, program-controlled telephone exchange, dual-tone multi-frequency dialing, voice digital sampling and so on. In recent years, new technologies include ISDN, DSL, VoIP, analog mobile phone and digital mobile phone.
This industry is usually divided into telephone equipment manufacturers and telephone network operators. Historically, network operators usually have a national monopoly position. In recent years, with the opening and integration of the global telecommunications market and the development of technology, there has gradually emerged a situation in which many operators compete in the same market. For example, Bell system, that is, AT & amp； T's subsidiary once owned 80% of the American telephone market. During the period of 1984, Bell system was forced to be divided into several independent local Bell companies due to the antitrust lawsuit of the US Department of Justice. There is a saying that can explain this phenomenon: At & amp； Before T was divided, IBM was the second largest company in America. at at & at； After T was divided into seven companies, IBM ranked eighth.
Telephone communication is a communication technology that uses electricity as the medium and transmits language through the mutual conversion of acoustic energy and electric energy. The simplest way for two users to communicate is to connect two phones with a pair of wires.
When the speaker picks up the phone and speaks into the microphone, the vibration of the vocal cords excites the air to vibrate, forming sound waves.
Sound waves act on the microphone to generate current, which is called speech current.
Voice current is transmitted along the line to the receiver of the other party's phone.
The function of the receiver is just the opposite of that of the microphone-it converts the current into sound waves and transmits them to people's ears through the air.
In this way, the simplest call process is completed.