Which technology operates over the Public Switched Telephone Network (PSTN)?

Dial-up technology operates over the Public Switched Telephone Network (PSTN), utilizing standard telephone lines to establish an internet connection. This method involves modulating digital data into analog signals that can be transmitted over the voice-grade telephone lines, making it compatible with the existing infrastructure of the PSTN.

Dial-up connections typically operate at lower speeds compared to newer technologies, with a maximum speed of 56 Kbps for standard modems. The use of the PSTN means that dial-up can be accessed almost anywhere there is a telephone line, although it requires the line to be free for internet use, which can limit simultaneous voice calls.

In contrast, other technologies mentioned, such as cable connections, ADSL, and fiber optics, utilize different mediums and infrastructures. Cable connections rely on coaxial cable networks, ADSL utilizes existing telephone lines but operates on a different technology allowing for higher speeds simultaneously with voice calls, and fiber optics depend on light transmitted through glass fibers, providing significantly higher bandwidth and speed but requiring specific infrastructure.