CELLULAR SYSTEM

Fundamental concept of cellular system:

Let see example of cordless telephone used at home which employed wireless technology, which has less coverage and smaller amount of power. All the users use same frequency range without much inference among users. Same frequency interference avoidance is used in cellular system with much more powerful transmitting station, or base station.

Introduction to cellular concept:

A cell is defined as the use of mobile station radio communication resources is under the control of the base station. Depending on the size, shape and amount of resources allocated to each cell determines the performance of the system.

Cell area:

The important factor in the cellular system is the size and shape of the cell. Transmitter or base station coverage area is called a cell, base station serve all the mobile station connected to it in that area. Whereas the coverage area of the base station can be represented by a cellular cell with a radius R from the center of the base station. While the many factors affecting the signal strength including refraction of the signal, reflection, elevation of the terrain due to the presence of tall buildings or valleys, or hills. Received signal strength will determine the original shape of the cell. Cell boundaries are represented by using different models are hexagon, square, and equilateral triangle. From the available model hexagon mostly used model due to its arrangement style. In a hexagon, multiple hexagons is arranged next to each other, without having any spacing between two hexagons without any overlapping area. Another most popular model is a rectangular shape, which is similar to the hexagon model. If the cell area is increased the number of the channels per unit area is reduced for the same number of channels and if the populated area is less it is good which has fewer subscribers.