Evolution of Mobile Radio Communications

Evolution of Mobile Radio Communications

The rst wireline telephone system was introduced in the year 1877. Mobile communication
systems as early as 1934 were based on Amplitude Modulation (AM)
schemes and only certain public organizations maintained such systems. With the
demand for newer and better mobile radio communication systems during the World
War II and the development of Frequency Modulation (FM) technique by Edwin
Armstrong, the mobile radio communication systems began to witness many new
changes. Mobile telephone was introduced in the year 1946. However, during its
initial three and a half decades it found very less market penetration owing to high

costs and numerous technological drawbacks. But with the development of the cellular
concept in the 1960s at the Bell Laboratories, mobile communications began to
be a promising eld of expanse which could serve wider populations. Initially, mobile
communication was restricted to certain ocial users and the cellular concept was
never even dreamt of being made commercially available. Moreover, even the growth
in the cellular networks was very slow. However, with the development of newer and
better technologies starting from the 1970s and with the mobile users now connected
to the Public Switched Telephone Network (PSTN), there has been an astronomical
growth in the cellular radio and the personal communication systems. Advanced
Mobile Phone System (AMPS) was the rst U.S. cellular telephone system and it
was deployed in 1983. Wireless services have since then been experiencing a 50%
per year growth rate. The number of cellular telephone users grew from 25000 in
1984 to around 3 billion in the year 2007 and the demand rate is increasing day by
day. A schematic of the subscribers.