advanced mobile phone system

telecommunications

Also known as: AMPS

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Last updated

July 23, 2026

Quick Summary

The Advanced Mobile Phone System (AMPS) was a cellular telephone system developed primarily by AT&T and Motorola. It was an analog system that used frequency modulation (FM) and operated in the 800-megahertz band. AMPS was designed to support both vehicle-based and pedestrian users, allowing for greater mobility than previous mobile telephone services.

Key characteristics of cellular communication, including AMPS, involve dividing geographic areas into smaller "cells," each served by a base station. This cell structure allows for frequency reuse in non-adjacent cells, significantly increasing the system's capacity. When a mobile user moves between cells during a call, a central controller automatically reroutes the call through a process called "handoff," ensuring an uninterrupted signal. As demand increases, cells can be "split" into smaller ones to accommodate more users. AMPS was publicly introduced in 1983 and was highly successful, leading to millions of subscribers. It laid the groundwork for subsequent generations of mobile communication technologies.1

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telecommunication
Frequency-division multiple access
In the advanced mobile phone system (AMPS), the cellular system employed in the United States, different callers use separate frequency slots via FDMA. When one telephone call is completed, a network-managing computer at the cellular base station reassigns the released frequency slot to a new caller. A…
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In the advanced mobile phone system (AMPS), the cellular system employed in the United States, different callers use separate frequency slots via FDMA. When one telephone call is completed, a network-managing computer at the cellular base station reassigns the released frequency slot to a new caller. A…
Read More

mobile telephone
Development of cellular systems
…cellular system, known as the advanced mobile phone system, or AMPS, was developed primarily by AT&T and Motorola, Inc. AMPS was based on 666 paired voice channels, spaced every 30 kilohertz in the 800-megahertz region. The system employed an analog modulation approach—frequency modulation, or FM—and was designed from the outset…
Read More
…cellular system, known as the advanced mobile phone system, or AMPS, was developed primarily by AT&T and Motorola, Inc. AMPS was based on 666 paired voice channels, spaced every 30 kilohertz in the 800-megahertz region. The system employed an analog modulation approach—frequency modulation, or FM—and was designed from the outset…
Read More