The greedy forwarding routing protocol has been widely used for constructing a route with low control overheads in wireless sensor networks. However, its performance drops significantly when obstacles exist. This paper proposes a novel mechanism, named WRGP, which removes the impact of obstacles on the greedy forwarding routing. The proposed WRGP initially applies the previous research to specify the border nodes that surround the obstacle. Then the border nodes in the concave region of the obstacle initiate the weight assigning process and establish a forbidden region to prevent the packets from entering the concave region. Finally WRGP specifies some border nodes to act as the effective border nodes for constructing the optimal routes from themselves to the sink node. Comparing with the existing obstacles-resisting protocols, the proposed WRGP avoids the ping-pong effect and guides the packets moving along the shortest path from the encountered effective border node to the sink node. In addition, the M-WRGP is further developed to cope with the multi-obstacle problem. Simulation results show that both WRGP and M-WRGP outperform the existing protocol PAGER in terms of control overheads and average route length.
IEEE International Conference on Communication (IEEE ICC) 2008, Beijing, China