What is Public Switched Telephone Network (PSTN)

The Public Switched Telephone Network (PSTN) is a system of interconnected voice-oriented public telephone networks built on copper cables delivering analogue voice data around the world. It is made up of a group of hardwired individual telephones connected to a public exchange.

It is both privately and publicly owned. It’s also known as POTS (Plain Old Telephone Service) (POTS). Circuit switching is used by the PSTN. Telephone lines, fibre optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables make up the PSTN, which is interconnected by switching centres and allows most telephones to communicate with one another.

Previously, the public switched telephone network was simply referred to as the telephone network. This network was designed primarily for analogue voice transmission across countries and continents via cables. It is an advancement over Alexander Graham Bell’s original telephone system.

The Bell Telephone Corporation in the United States was the first company to be formed to provide PSTN services. Except for the final link from the central (local) telephone office to the user, technology is virtually fully digital today. Subscribers can be connected to the Public Switched Telephone Network (PSTN) by dialling telephone numbers.

The current connections are largely utilised to send speech data. The connection is ended when you hang up, and the resources you utilised become available to other subscribers.

Switching From Public Switched Telephone Network Over Voice over IP telephony (VoIP)

As smartphones and mobile devices become more common, wireless telecom networks are gaining market dominance, while PSTN landline technology is dwindling as Voice over IP telephony becomes more prevalent (VoIP).

VoIP has posed a greater threat to PSTN operators than any other technology by allowing individuals to communicate for free or at a reduced cost locally and globally.
For speech communication, Voice over IP uses the internet and sends voice data in individual data packets.

There is no static link between the two subscribers on public switched telephone networks; instead, data is dynamically routed over the data network using a virtual connection. The packets can even be routed differently over the network because each data packet has a destination address.