Active Route-Guiding Protocols for Resisting Obstacles in Wireless Sensor Networks

In wireless sensor networks, a geographic region without the functionality of sensing and communication can generally be treated as an obstacle, which significantly impacts the performance of existing location-based routing. An obstacle can dynamically be formed due to unbalanced deployment, sensor failure, or power exhaustion, animus interference, or physical obstacles such as mountains or buildings. This paper proposes novel algorithms that enable the existing location-based routing protocols that resist obstacles. Applying the proposed active route-guiding protocol for single obstacles (S-RGP), border nodes that surround the obstacles will actively establish a forbidden region for concave obstacles and make the obstacle information transparent. Then, packets will be guided to overcome the obstacle and move along the shorter path from the encountered border node to the sink node. In addition, the proposed active route-guiding protocol for multiple obstacles (M-RGP) takes multiple obstacles into consideration and integrates their information to help the packets overcome multiple obstacles. Simulation results show that the proposed S-RGP and M-RGP create low overhead and significantly reduce the average route length, and, therefore, improve the energy consumption and end-to-end delay for a wireless sensor network with obstacles.