Assessment of Radio Coverage in Indian Cities Using FDTD

Abstract

Prediction of Radio coverage has seen a massive surge of research in recent years. In this paper we attempt to predict the radio coverage of an extremely complicated urban scenario using a very sophisticated mathematical model called Finite-Difference Time-Domain (FDTD). FDTD technique helps us to model an urban area, with different obstacles, by numerically implementing the Maxwell’s equations. This enables us to find the electric and magnetic field strength of different regions. As the simulation is based on basic laws of electromagnetic theory, all the physical phenomena occurring in an urban space are taken into consideration. We use particular electromagnetic parameters such as, electric permittivity, magnetic permeability and electrical conductivity of the materials which form the obstacles. They are aided with the transmission data i.e Transmission power and frequency for deriving the radio power. The simulation is based on a 2 dimensional model of FDTD. This greatly increases our accuracy in complicated scenarios. This also helps us in finding the specific regions that are under very high exposure to radio signals and thereby accessing the risk of health hazards in such regions. In a last few decades, there has been a surge of research and novelty in prediction of radio power and radio coverage in different regions. The requirement of effective algorithms and proper platforms for simulations has been a prime driving cause. There are a number of models in place for determining radio power in a particular area. But the current tools are based on empirical and semi-empirical models for easier algorithms and short running time. These models have shown effective results in rural and semi-urban scenarios. But they seem to fail in extremely complicated urban scenarios, where all the obstacles must be accurately modelled. In these scenarios, we must take all possible physical phenomena, such as reflection, refraction, diffraction, transmissions and scattering, into consideration.