In this post I continue discussing some of the different legacy technologies used by the Public Switched Telephone Network (PSTN). Today let's take a dive into analog or frequency multiplexing.
This 240KHz is placed in the frequency range of 312 – 552 KHz.
This 2.40MHz is placed in the frequency range of 564 – 2.964 MHz.
This 14.4 MHz is placed in the frequency range of 3.084 – 17.484 MHz.
Frequency multiplexing is now considered obsolete technology on the telecommunications network. Analog signals are more sensitive to noise and other signals which can cause problems along the transmission path. Those long coaxial cables make pretty good antennas. They have been replaced with digital multiplexers. In my next legacy PSTN post I'll cover how digital multiplexing works.