The first mobile service was introduced in America in 25 major cities in year 1946. In which each system used a single & high-powered transmitter .A large tower was used in order to cover distances of over 50 km in a particular market. As the demand for wireless service increases, the number of channels assigned to a cell eventually becomes insufficient to support the required number of users. At this point, cellular design techniques are needed to provide more channels per unit coverage area