Energy equivalence routing in wireless sensor networks

Energy is a critical resource in wireless sensor networks. In this paper, we propose a new approach to maintain network wide energy equivalence and maximize network lifetime. Compared to existing protocols, our approach emphasizes on route maintenance instead of route finding. This means no critical nodes would become the bottleneck of network lifetime. A reroute request packet is sent out from sinks periodically. When the packet reaches a path node, Common Neighbor Switching (CNS) algorithm checks energy difference between the node and its neighbors outside the routing tree. If the difference goes beyond a threshold, double neighbor switching is performed. Two path-rerouting algorithms, namely, Shortest Rerouting (EERS) and Longest Rerouting (EERL), are a] so presented to show that neighbor switching is better than path rerouting. Simulation results show that CNS outperforms Directed Diffusion in more than 90% cases, while EERS and EERL show only blurry and conditional advantage over directed diffusion. (C) 2004 Elsevier B.V. All rights reserved.