In 1970, when Joel was working as
an electrical engineer as Bell Labs, in Murray Hill, New Jersey, Amos Joel
(b.1918) came up with an idea that worked so well that many of us use it today
without noticing that anything has happened at all. Joel had invented the idea of the cellular
mobile phone.
Cell phones existed prior to
1970, but they had problems. Since each
call was made on a single channel, the number of simultaneous calls was limited
to the number of available channels.
Additionally a cell phone could not leave the base station are of
coverage in which the cal was initiated or the connection to the network would
be lost.
Joel’s cellular mobile
communication system proposed providing phone service to a geographic area by
dividing it up into many small, low-powered base stations or “cells”. This network of cells could deal with a
greater number of simultaneous calls by allocating a radio channel to a call in
one cell and reusing the same radio channel in a number of other cells
separated by enough distance to prevent interference. When a user traveled from the service area of
one cell to another, the user’s phone call would not be disrupted as each cell
would “hand-off” to the other, switching cellular base stations and radio
channels without anyone noticing.
The key ingredients-A
microprocessor that could make all the decisions, identify the phone, find
cellular base stations and control the connections as users moved through the
network. Today’s cell phones support a
number of additional services such as text messaging, access to the internet
and camera.
“Motorola produced the first
commercially approved cellular phone in 1983.
It weighed 28 ounces (794gms)”.
