How a POT line work?

Answer 1

A POT line (plain old telephone line) is a twisted pair of copper wires that connects a traditional telephone -- aka "landline", aka "hard-wired phone" -- to the telephone company POP building ("point of presence").

Many communication systems, such as some kinds of power-over-Ethernet, use one pair of wires to carry power out, one pair of wires to carry data out, and one pair of wires to carry data in -- 3 separate pairs of wires.

The POT system somehow combines all three functions onto a single pair of wires.

A POT line uses the "bias-T" technique with a an inductor to combine and split data and power at the ends of the line. (Sometimes a gyrator circuit simulating an inductor is used at the POP end).

A POT line uses "echo-cancelling" techniques to combine and split incoming and outgoing data lines at the POP end of the line.

Answer 2

A Plain Old Telephone Service (POTS) line is a traditional analog phone line that transmits voice signals through copper wires to connect callers. The POTS system requires a physical copper wire connection between the caller and the receiver, enabling the transmission of voice signals in analog form. When a call is placed, the analog voice signal is converted to electrical signals that travel through the phone line to reach the recipient.