What is PSTN ?

PSTN stands for Public Switched Telephone Network. It is the traditional telephone network that has been in use for over a century, providing voice communication over copper wires.

The PSTN is a circuit-switched network that connects landline phones, allowing for local, long-distance, and international calls. It includes a vast infrastructure of telephone lines, switches, and exchanges, and is often referred to as the “landline” or “legacy” phone network.

Key characteristics of PSTN:

  1. Analog Communication: Traditionally, it used analog signals to transmit voice data, though much of the network has been upgraded to digital technology.
  2. Circuit-Switched: This means a dedicated path or circuit is established for each call, ensuring a constant, stable connection for the duration of the call.
  3. Voice-Only: The PSTN was primarily designed for voice calls, though modern upgrades allow some data transmission as well (such as dial-up internet or fax).

With the advent of mobile networks and Voice over Internet Protocol (VoIP) technology, PSTN usage has declined, but it is still in operation in many areas.