Improvement in Accuracy of Breakpoint Distance Model for Path Loss Prediction

Positioning algorithms of wireless terminals that are based on received signal strength (RSS) require highly accurate prediction of RSS. Revisiting breakpoint distance models for path loss prediction is essential for new applications of wireless communications such as wireless localization and dense interference calculations. The breakpoint distance is defined as the distance that separates two different trends of path loss that follows two different path loss exponents. The most widely used breakpoint distance model is based on Fresnel zone theory as the distance where the first Fresnel zone along direct ray begins to obstruct ground surface. In this work, we improve the accuracy of this model and extend its application to different polarization and propagation over water (e.g., sea) reflection surface.