'modem-based' originates from the combination of 'modem' and 'based', where 'modem' is derived from 'modulator-demodulator', a device that converts digital data to analog signals and vice versa.

'Modem' evolved from the need to transmit digital data over analog telephone lines, leading to the creation of devices that modulate and demodulate signals.

Initially, 'modem' referred specifically to the hardware device, but over time, it has come to represent any technology or system that uses modems for communication.