Measurement Based Physical Layer Modeling for Wireless Network Simulations

Simulation methods have become an integral part of almost all aspects of networking research and particularly in the area of wireless networks. Any new protocol or methodology that is proposed for wireless networks almost always will be demonstrated using simulations. However, there is little evidence that existing models of physical layer signal propagation and signal strength calculations produce realistic or meaningful results. Indeed, there have been a number of empirical studies that have shown little predictability in measured signal strength and packet receipt probability for deployed networks. Common assumptions used in simulation models about the behavior of the wireless signal have been shown to often be invalid. These prior works motivated us to design a stochastic model for wireless signal propagation in our GTNetS simulator. Our model is based on a detailed empirical measurement study and uses random variations to produce more realistic behavior for wireless packet transmissions and reception modeling.