Lecture 25: The Telephone System

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Lecture 25: The Telephone System

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The telephone system remains as the backbone of low-cost telecommunications services in North America. An understanding of the telephone system is necessary when considering its use for data communications. Telephone: invented in 1874 by Alexander Graham Bell and patented in 1876 Single wire: In the beginning, the market was for telephones only. It is the customer who used to wire them between telephones using single wires and the earth as the ground or the other conductor to complete the circuit. ...

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