What is PSTN?

Local, regional and national telecommunications companies operate the PSTN. The connected circuit-switching public telephone networks allows for landline telephone calls to be made. Today, both homes and businesses use the PSTN to call one another.

Continue reading to learn more about the PSTN basics and how the network functions.

What does PSTN stand for?

PSTN stands for Public Switched Telephone Network. This network is also referred to as the Plain Old Telephone Service (POTS).

How does the Public Switched Telephone Network work?

PSTN uses circuit switching to allow users to make landline telephone calls to one another. The call is placed after it is routed through multiple switches. These switches are found in a central office (CO) or in a wire center. Ultimately, voice signals are able to travel over the connected phone lines.

The development of the Public Switched Telephone Network

Before the PSTN, two telephones needed to be connected over a copper wire in order to make a phone call. Because of the small number of connections, very few people could actually call each other. Soon enough, there was a demand for the PSTN. A copper wire connected individual landline telephones to a local telephone exchange, creating the PSTN. While the network started off local, it now is an international landline phone service network.

How voice signals are carried over the Public Switched Telephone Network

When two telephones are connected, analog voice data is transmitted over the copper wires of the PSTN. The voice data is then converted into electrical signals which are eventually routed in the switching centers. Finally, a connection is made and communication is possible.

The advantages of the Public Switched Telephone Network

Thanks to the PSTN, homes and businesses can make both local and long distance telephone calls. Callers can speak and be heard by one another because communication is bidirectional. Subscribers can receive service from their local telecommunications company.