17.1 Introduction to Cellular Systems

Although cellular radio is a relative newcomer to mobile communications, the concept of a cellular system dates back to the early 1940s, and the principle of a mobile phone system goes back still earlier. The first mobile phone system was an experimental system installed in 1921 by the Detroit police department. It used transmission frequencies at 2 MHz band and was capable only of one-way transmission. The called police officer had to use the public telephone network to answer the call. But it was the predecessor of today s mobile phone networks.

The cellular concept was conceived in the 1940s. Planners imagined a system of transmitters that could cover certain geographic areas and provide very efficient communications for a large number of users. Unfortunately, however, the technology required to realize such a system wouldn t exist for almost another 40 years. The objective of providing two-way communication became more realizable as the basic concepts were moved upwards in frequency, and the development of VLSI made it possible to reduce the physical size and power consumption of the devices, thus opening up new opportunities in the deployment of cellular radio systems.

Today s mobile telephone systems began in earnest with the Mobile Telephone System (MTS) in 1964. It operated at 150 MHz band and its major advancement...