Virtual Convex Polygon Based Hole Boundary Detection and Time Delay Based Hole Detour Scheme in WSNs

In wireless sensor networks, an important issue often faced in geographic routing is the "local minimum phenomenon." To mitigate the local minimum issue, when the routing process becomes stuck at hole boundary nodes, the existing perimeter routing tends to route data packets along the boundaries of the holes. However, this may enlarge the hole, causing the "first hole diffusion" problem. On the other hand, the existing hole detour scheme based on the virtual ellipse forwards data packets to outside the virtual ellipse. This may generate other holes around the existing hole - the "second hole diffusion" problem. Therefore, we propose a novel virtual convex polygon based hole boundary detection and time delay based hole detour scheme. The proposed scheme solves first and second hole diffusion problems. Comprehensive simulation results show that the proposed scheme provides approximately 22% and 16% improvements in terms of the packet delivery ratio and the network lifetime, respectively.