Associate Professor,

Abstract: This work deals with the concept of a underground wireless communication systems modeling especially in mines and tunnels using existing terrestrial wireless models. The need for efficient underground communication systems has increased with increase in number of tunnels, metros, mines etc. Even though the basic principles of communication remain the same, the factors which are to be considered vary voraciously in case of underground. Unlike terrestrial environment, underground environment poses variety of challenges like humidity, wall penetration, bends, excess attenuation of signals, scattering over rough surfaces, multiple reflections etc. The model selected for the study in this case is COST231 model. This paper takes in to consideration some major losses which affect the signals in such environments to obtain the suitable correction factors pertaining to those losses. Then the conventional path loss equation is modified by adding the correction factors and a hybrid model is obtained from the existing terrestrial wireless communication models. This hybrid model holds good for most of the cases of underground communication, provided the conditions are satisfactory (ex. The operating frequency is around 900 MHz