9.1 Introduction

The cellular concept [1] refers to the scheme adopted by the most importantwireless systems. Using this concept it is possible to serve at a reasonable priceentire countries or even continents using a limited portion of the RF spectrum.The cellular concept is based on two main key points:

• Frequency reuse;
• Cell splitting.

As an illustration of the concepts covered in this chapter, a brief descriptionof the advanced mobile phone service (AMPS) system used in North Americaand its European version total access cellular system (TACS) will be given.

A cellular layout in a wireless communication network permits the adequatefulfillment of the following objectives [1]:

1. High user capacity;
2. Efficient use of the RF spectrum;
3. Extended coverages up to national or continental level;
4. Adaptability to different traffic density conditions;
5. Provision of service to mobile and hand-held terminals;
6. Telephone service plus special services including dispatching;
7. Service quality similar to that of the fixed telephone network;
8. Affordable price.

9.2 Keys to The Cellular Concept

To introduce the cellular concept, an illustrative example will be given relativeto the so-called zero generation public mobile telephony (PMT) systems. Inthese systems a high-power multichannel control transmitter was employed forthe downlink direction (from the base to the mobile stations). The mobileuplink range limitations were solved by using voting receivers (see Chapter 2)with a coverage that matched the lower transmission powers of the mobiles.

Suppose that a PMT system covering a town and its suburbs is set up.Assume that the coverage area is a circle of radius R =...