1921
The Detroit Police Department in 1921 implemented a radio that
system allowed the patrol cars to communicate a central control
point, although this system has little in common with today's
sophisticated modern communications systems, it was the first
mobile communications system.1939 - 1944 (World War II)
World War II proved that the mass production of VHF radios was
possible, by the end of the 1940's there seems to be little standing
in the way of the development of mobile communications systems.
1946
By 1946 in St. Louis it became possible link a vehicle mounted
mobile radio unit to a PSTN (Public Switched Telephone Network).
PMR & PAMR (Private Mobile
Radio & Private Access Mobile Radio)
These systems were developed by during the 1950's, usually utilising
vehicle mounted units. These systems are mainly used by the emergency
services, public utilities, road haulage and taxi's. To start
with these systems were very basic single site and single channel.
However they have developed into much more complex systems, utilising
multi site, multi channel, selective calling, connections PABXs/PSTN's
and direct calling. (TETRA(Terrestrial Trunked Radio).
TACS (Total Access Communications
System)
TACS was the first real mobile communications system*. In 1985
when this system was introduced it was mainly vehicle mounted
units, but later developed into mobile units. Unlike the other
systems used around the world TACS used the 900 MHz band.
* In the United Kingdom
|