Analog Mobile

In 1983, the analog cell-phone standard called AMPS (Advanced Mobile Phone System) was accepted by the FCC and first used in Chicago. AMPS utilizes a range of frequencies between 824 megahertz (MHz) and 894 MHz for analog cell phones. In order to promote competition and remain prices low, the U. S. government required the existence of two carriers in every market, known as A and B carriers. One of the carriers was generally the local-exchange carrier (LEC), a fancy way of saying the narrow phone company.

AMPS was a first-generation cellular technology that uses split frequencies, or "channels", for each conversation (see FDMA). It therefore required extensive bandwidth for a large number of users. In general terms, AMPS was very comparable to the older "0G" Improved Mobile Telephone Service, but used significantly more computing power with the intention of select frequencies, hand off conversations to PSTN lines, and handle billing and call setup.

What really alienated AMPS from older systems is the "back end" call setup functionality. In AMPS, the cell centers could flexibly consign channels to handsets founded on signal strength, allowing the same frequency to be re-used in diverse locations without interference. This permitted a larger number of phones to be supported over a geographical area. AMPS pioneers fathered the term "cellular" because of its use of small hexagonal "cells" within a system