  Channel properties influence the development of wireless communication
systems. Unlike wired channels that are stationary and predictable, radio
channels are extremely random and dont offer easy analysis. A Radio Propagation
Model (RPM), also known as the Radio Wave Propagation Model (RWPM), is an
empirical mathematical formulation for the characterization of radio wave
propagation as a function of frequency. In mobile radio systems, path loss
models are necessary for proper planning, interference estimations, frequency
assignments and cell parameters which are the basic for network planning
process as well as Location Based Services (LBS) techniques. Propagation models
that predict the mean signal strength for an arbitrary transmitter receiver (T
R) separation distance which is useful in estimating the radio coverage area of
a transmitter are called large scale propagation models, since they
characterize signal strength over large TR separation distances. In this paper,
the large scale propagation performance of Okumura, Hata, and Lee models has
been compared varying Mobile Station (MS) antenna height, Transmitter Receiver
(TR) distance and Base Station (BS) antenna height, considering the system to
operate at 900 MHz. Through the MATLAB simulation it is turned out that the
Okumura model shows the better performance than that of the other large scale
propagation models.
