Modeling for Geo-Routing in Multi-Hop Wireless Networks

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 work describes a physically realistic model for the log-normal correlated shadow fading loss, and investigates the importance of the shadowing correlation length on designing protocols for ad hoc and sensor networks. Nodes that are geographically proximate often experience similar environmental shadowing effects and can have correlated fading. This work also describes an evaluation procedure, which produces statistically meaningful results over a large number of realizations of multi-hop networks. This procedure takes into account the overall path loss (shadow fading and median path loss) based for antennas working at 2.4 GHz with heights ranging from 0.5 to 1.8 m. Finally, we analyze and compare the performance of the localized position-based greedy algorithm used for Unit Disk Graph (UDG) and the probabilistic position-based greedy algorithm on the proposed model for different values of standard deviation (σ) of shadow fading to show the importance of both the shadow fading and correlation length while designing the protocols for ad hoc networks.