h loss over multiple obstacles, namely, the irregular terrain scenario. 6.4 CONCLUSION In this work, the UTD-PO and the FKE approaches are studied to predict the path loss over an irregular terrain scenario. This scenario is a series of obstacles or hills of UTD-PO and FKE Models for Path Loss Prediction uneven height and spacing which is approximated as knife edge obstacles to predict path loss between transmitting and receiving points. The results of these scenarios show that when the path loss is predicted for one obstacle between the transmitting and the receiving point, both the approaches give exactly same results. But when the number of obstacles is increased to more than one, path loss for the FKE approach gives inferior results when compared with the path loss of measurement data and the path loss of the UTD-PO approach. Also, data analysis shows that the mean error for both the approaches in the case of one obstacle is same, but when the number of obstacles is more than one, the mean error of the UTD-PO approach is smaller than the mean error of the FKE approach. These results show that the predictions of path loss through the UTD-PO approach over a multiple obstacle scenario gives more accurate results than the FKE approach. REFERENCES 1. Rodríguez, J. V. et al. A new solution for the analysis of multiple-building diffraction in urban areas with shadowing caused by a cylindrical hill. IEEE Transactionon Antennas and Propagation 55(9): 2632-2636, 2007. 2. Durkins Computer Prediction of Service Areas for VHF and UHF Land Mobile Radio Service. IEEE Trans. Veh. Technol. 26(4): 323-327, 1997. Leubbers, R. J. Finite Conductivity uniform GTD versus Knife Edge Diffraction Prediction of Propagation Path Loss. IEEE Trans. Antennas Propagat. A32: 70- 76, 1984. 4. Eliades, D. E. Terrain Simulation for the Cascadeed Cylinder Diffraction Model. IEE Proceeding-H 140(4): 285-291, 1993. 5. Luebbers, R. J. Propagation Prediction for Hilly Terrain Using GTD Wedge Diffraction. IEEE Trans. Antennas Propagat. AP- 32(9): 951