Realistic physical layer modelling for georouting protocols in wireless ad-hoc and sensor networks

Abstract

Existing routing and broadcasting protocols for ad-hoc networks assume an ideal physical layer. In reality, an accurate representation of physical layer is required for analysis and simulation of multi hop networking in sensor and ad-hoc networks. This paper describes the model for the lognormal correlated shadow fading loss from the first principles of probability theory, and investigates the importance of correlation length while designing protocols for ad-hoc and sensor networks. Nodes that are geographically proximate often experience similar environmental shadowing effects and can have correlated fading. We consider the overall path loss (shadow fading & median path loss) based on antennas working at 2.4 GHz with heights ranging from 0.5 metres to 1.8 metres. Finally, we analyze and compare the performance of localized position based greedy algorithm used for Unit Disk Graph (UDG) and probabilistic progress based algorithm on the proposed shadowing model for different values of standard deviation (σ) of shadow fading to show the importance of both the shadow fading and correlation length.