Probabilistic Forwarding Decision Scheme for Reliable Geocasting in Wireless Sensor Networks

Geocasting is an important communication service in wireless sensor networks. Most of the existing geocasting protocols assume that sensor nodes and the area of interest have accurate location information. However, this assumption is unreasonable if localization systems or schemes cannot work well. This study proposes an efficient probabilistic forwarding decision scheme for reliable geocasting in virtual coordinate-based wireless sensor networks. The proposed scheme uses directional code and hop distance to identify sensor node’s location. The sensor node determines a direction-based probability and a distancebased probability derived from its directional code and hop distance, respectively. The sensor node depends on the two probabilities to determine its ultimate forwarding probability. Simulation results confirm that the proposed scheme outperforms the pure direction-based forwarding scheme in packet delivery ratio though it occurs more packets. Results also show that the direction-based probability significantly dominates the geocasting performance.